A . / T H E TEA RESEARCH INSTITUTE OF CEYLON Report for the Year 1968 Part II \ y — Published by THE TEA RESEARCH INSTITUTE OF CEYLON ST COOMBS. TALAWAKELE. CEYLON 1969 The Tea Research Institute of Ceylon, Talawakele The laboratories and headquarters of the Institute are situated at St Coombs Talawakele. Correspondence, enquiries, specimens, soil samples and other consignments should be addressed to The Director Tea Research Institute of Ceylon St Coombs Talawakele Telegraphic Address Railway Station : Telephones : Forwarding Agents : RESEARCH, TALAWAKELE TALAWAKELE Talawakele 44 \ Tillicoultry 35 J Radella 36 Radella 32 Open at all hours; extensions to the Director's office, all Divisions and Senior Staff bungalows Director's office during office hours only Chief Administrative Officer during office hours only Messrs M. Y. Hemachandra & Co. (Transporters) Ltd., Talawakele, Mas- keliya, Norwood and Colombo. It is particularly requested that letters should not be addressed to officers by name. Consign­ ments sent by rail should be forwarded to the Railway Station, Talawakele, c'/o the Forwarding Agents. Carriage must be pre-paid. Accommodation : The Guest House at St Coombs is open to persons visiting the TRI and St Coombs Estate on business. Prior permission for accommodation must be obtained in writing from the Director, Tea Research Institute of Ceylon, St Coombs, Talawakele. Unless sufficient notice is given, accommodation cannot always be guaranteed. A list of rules and charges is available on request. The TRI Low-Country Station, Ratnapura Low-country estates in the Sabaragamuwa, Southern and Western Provinces should address their correspondence, enquiries, plant specimens and soil samples to The Advisory Officer TRI Low-Country Station St Joachim Ratnapura Telegraphic Address : RESEARCH. RATNAPURA Railway Station : RATNAPURA Telephones : Ratnapura 428 — Extension to Assis­ tant Director's bungalow Ratnapura 359 — Extension to Supe­ rintendent's bungalow The TRI Mid-Country Station, Kandy Mid-coun'ry estates in the Central Province should address their advisory enquiries and plant spscime is to The Advisory Officer TRI Mid-Country Station Hantane Estate Kandy Telegraphic Adlress Railway Station : Telephone : RESEARCH. K A N D Y K A N D \ Kandy 7lo9 Tha TRI Uva Stat ioi , Debcdde Estates in the Uva Province should address their advisory enquiries, plant specimens and soil samples to The Uva Scientific Officer Telegraphic Address : RESEARCH, DEBEDDE TRI Uva Station Railway Station : BADULLA Gonakelle Estate Telephone : Passara 546 Debeddc Until further notice, soil samples for pH determinations and eelworm counts should be addressed to the Director, Tea Research Institute of Ceylon, St Coombs, Talawakele. Visitors—Visitors to the Institute's headquarters and laboratories at Tilawakele, the Low- Country Station at Ratnapura, The Uva Station at Debedde, The Mid-Country Station at Kandy, St Coombs Estate and St Joachim Estate are welcome on any day, provided they make a prior appointment with the officer they wish to meet. Subscriptions The post-free subscription for Annual Report is Rs 6/- per annum for persons resident in Ceylon, India or Pakistan, and £0-7-0 for those resident elsewhere. Copyright—Mo part of this journal may be reproduced in any form without the written permission of the Director, Tea Research Institute of Ceylon. T H E TEA RESEARCH INSTITUTE OF CEYLON Report for the Year 1968 Part II Edited by L. H . F E R N A N D O , BSc , P h D (Lond) £ and R. L. D e SILVA, BSc (Cey), P h D (Load) , D I C Published by T H E T E A R E S E A R C H I N S T I T U T E O F C E Y L O N ST C O O M B S , T A L A W A K E L E , C E Y L O N 1969 1 PAGE The Board of the Tea Research Institute of Ceylon 5 The Staff of the Tea Research Institute of Ceylon 6 Report of the Director 9 Report of the Agricultural Chemistry Division . . I . . 18 Report of the Plant Physiology Division 39 Report of the Plant Pathology Division 58 Report of the Nematology Division . . 70 Report of the Entomology Division . . 79 Report of the Biochemistry Division . . . . 93 Report of the Technology Division 102 Report of the Statistics Division 111 Report on the Low-Country Station and the Kottawa Substation 112 Report on the Mid-Country Station 141 Report on the Uva Station 150 Report of the Advisory Division . . 155 Report on St Coombs 157 Report on St Joachim . . 167 Meteorological Observations The Tea Research Institute Laboratory, Talawakele . . 175 The Low-Country Station, Ratnapura . . . . 176 The Mid-Country Station, Kandy . . . . . . 177 The Uva Station (Gonikelle), Debedde . . . . . . 178 Index to field experiments, trials & factory experiments . . . . 179 C O N T E N T S The Tea Research Instituteof Ceylon The Board as at 31st December 1968 Chairman: Vacant Ex-officio Members The Director of Agriculture : Mr M. S. Perera The Honourable the Minister of Finance : represented by Mr G. D. Loos The Chairman, Planters' Association of Ceylon : Mr B. Warusavitarne TJie Chairman, Agency Section, Planters' Association of Ceylon : Mr S. K. D. Jayamanne the Chairman, Low-Country Products Association of Ceylon : Mr T. C. A. de Soysa tlie Tea Controller : Mr C. P. Chanmugam The Director, Tea Researclx Institute of Ceylon : Dr L. H. Fernando Nominated Members Appointed by the Planters' Association of Ceylon : Mr S. P. Vytilingam Mr G. B. Middleton Mr J. R. Somerville Appointed by the Agency Section, Planters' Association of Ceylon : Mr P. J. C. Durrant Mr J. F. A, P. Peries Mr M. B. Horsfall Appointed by the Low-Country Products Association of Ceylon : Mr S. Pathmanathan Mr J. L. D. Peiris Mr G. Hettiarachchi Appointed by the Honourable the Minister of Agriculture to represent the smallholders: Mr D. E. Hettiarachchi Mr M. Rajendram, MBE Appointed by the Honourable the Minister of Agriculture to represent the House of Representatives : Mr D.J , Ranaweera, MP Secretary: Mr P. Kanapathipillai 5 TEA RESEARCH INSTITUTE.OF CEYLON Director Agricultural Chemistry Agricultural Chemist Research Officer Research Assistants Technical Assistants Biochemistry Biochemist -j^ o Research Officer Research Assistant .. Technical Assistants Entomology Entomologist Research Assistant .. Technical Assistants Nematology Nematologist Technical Assistants Plant Pathology Plant Pathofogisf: Research Officer Technical Assistants Plant Physiology Plant Physiologist . Research Officer Research Assistants f T H E S T A F F ' (On 31st December 196S) D I R E C T O R A T E .. . L. H. 'Fernando, BSc, P h D (Lond) R E S E A R C H D I V I S I O N S V. P. Bhavanandan, BSc (Coy), P h D (Edin), A R I C W. M. W. B. Manipura, BSc (Cey), P h D (Cantab) *S. Sandanam, BSc (Cey) , *S. SiVasubramariiam,BSc (Cey) 1 V. Fernando '. '•,,•;,• S. G. Jayasuriya . T.- G, Z. Jayman t . Kiilaratna, BSC (Cey) C. C. Rajasingham ; : r ; " v : " ' A. Somaratne, BSc (Cey) . S. SunderaIingam,.BSc (Poona) A. B. D . Wickremaratne, BSc (Vidyodaya. Cey) RvL. Wickrsmasinghe, BSc (Cey), BSc (Lond), P h D (Sheff), F R I C R. R. Selvcndran, BSc (Cey), P h D (Cantab) *G. R. Roberts, BSc (Cey), A R I C U . L. L. de Silva, B S c (Lond)' ," " W. A . B. de Silva, BSc (Cey) B. P. M. Perera • K. P. W. C. Perera, BSc (Cey) : K. Sivapalan, BSc (Cey), MSc (IARI, N e w Delhi) W. Danthanarayana, BSc (Cey), P h D (Lond), D I C D . J. W. Ranaweera K. D . Bandularatne, BSc (Cey) •S; .N. . Fernando, BSc (Cey) A . Kathiravetpillai. BSc (Cey) C. Shanmugam P. Sivapalan, BSc (Cey), P h D (Rutgers) A . R. M . Hassim P. A . John ' T. Manivasagar S. Samarajeewa V. ShivanandarajaK, BSc (Cey) ;N. Shanmuganathan, BSc (Cey), P h D (Lond) R. L. de Silva, B S c (Cey), P h D (Lond), D I C *P. V. Arulpragasam, BSc (Madras) R. N . Bopearatchy, BSc (Cey) 1 S. R. A . Fernando, BSc (Cey) S. Murugiah T. V. Saravanapavan. B S c (Cey) * U . Pethiyagoda, BSc (Cey), P h D (Lond) , D I C V. S. Kulasegaram, BSc (Cey), P h D (Lond), MI Biol »S. Kandiah, BSc (Cey) *S. Nagarajah, BSc (Cey), M S (Calif) * A : R. Sebastiampillai, BSc (Cey) f When more than one officer is listed under a designation, the names appear in alphabetical order * Working Overseas ANNUAL REPORT FOR 1968 Technical Assis tants A . S. B . G o m e z , B S c (Cey) " D . J a n a k i r a m , BSc ( M a d r a s ) , M S c ( I A R I . N e w Delhi ) S. Krishnapil lai , . BSc (Cey) H . R. So lomon H . B. Wijetunga S. W i m a l a d h a r m a Statistician Technical Assis tant ... Technology Technologis t Deve lopment Engineer Research Assis tants Technical Assistants Electrical F o r e m a n Electrician Mechanics Agriculturist H e a d Fac to ry Officer Act ing H e a d Clerk Field Officer Apo theca ry : - : ... Clerk of W o r k s W o r k s Clerk P. Kanapa th ip i l l a i , BSc ( L o n d ) . F S S K . Seevara tnam .. . D . Kir t is inghe, BSc (Cey), P h D (Lond) , D I C , A M I C h e m E , C E n g ... W. Joseph , BSc Eng (Cey) ... * N . M . Abdu l Gaffar, BSc (Cey) *W. C. A . de Silva, BSc (Cey) . . . W. A. C. de Silva , : ; S. J a y a r a t n a m , BSc (Cey) S. S a m a r a s i n g h a m A. Theva thasan , BSc (Cey) W . R . S o l o m o n .. . K . A . Bowie ... D . A . S. O p a t h a V, " ; .-. K . S . Vadivelu , ' ST COOMBS ... L . A . Seevara tnam, BSc (Dune lm) ... V. A . F e r n a n d e z . . . H . N . d c Silva ... W . Ar iyapa la . . . S. P . de Silva ... R. A . Danie l " " ' ^ . . . K . H . T . D a s s a n a y a k e O U T S T A T I O N S E R V I C E S Low-Country Service The Low-Country Station, Ratnapura Biochemist Research Officer Advisory Officer Deve lopmen t Engineer Technical Assistants Adminis t ra t ive Officer Accoun t s Clerk S tenographer Electrician W o r k s Clerk Super in tendent H e a d Fac to r ) ' Officer H e a d Clerk Field Officer R . L . Wickremas inghc , BSc (Cey), BSc (Lond) , P n D . - (She i f ) ,FRIC :v-'. D . T . Wet tas inghe , BSc (Cey) , P h D (Rcadini?)' J. V. Sabanayagam, BSA (Toron to ) , M S c (Guelpl i ) W . J o s e p h , BSc Eng (Cey) E. J . B.de Silva. BSc (Cey) U . L . L. de Silva; BSc (Lond) W . A. B . de Silva, BSc (Cey) C. K a n d a p p a h , BSc (Cev) A . A . C. K a r u n a r a t n c , BSc (Ccv) D . D . K r o o n . . . :• • . K . . P . . W . C. Pe re ra , BSc (Cey) N . S. Ra jendram, BSc ( M a d r a s ) * T ; F . Saldin, BSc (Cey) - : ? < H . H . S a m a r a k o o n ' U . P . de S. W a i d y a n a t h a , M S c (Cey) - v ; ; v ': N . Y o g a r a t n a m , BSc (A lahabad ) C. Ki r th i ra tne , F C C S T . R . B. Sally S. K . P . T a m b i m u t t u B; T . R a n a s i n g h e I . D . V. C o o r a y -.y: ST JOACHIM G. S. M u t t e t t u w e g a m a M . S. W . Wijera tne G . L . A . T h o m a s D . D . P a t h i n a y a k e * Work ing Overseas ANNUAL REPORT FOR 1968 The Kottawa Substation, Talgampola Officer in Charge . . . Technical Ass i s tant . . . Deniyaya Technical Ass i s tant . . . Mid-Country Service Mid-Country Scientific Officer Advisory Officer Technical Assistants K. H . G. Gunapala H . D . Jayasinghe J. I. H . Bandaranayake Uva Service U v a Scientific Officer Technical Assistants Clerk Act ing Chie f Advisory Officer Advisory Officers . . . Photographer Editors o f Publications Librarian . . . D . Calnaido, BSc (Cey), P h D (Lond) M . K. Vythilingam .. T. A . Munasinghe H. B. Ratnayakc K. Thirugnanasuntheran, B S c (Cey) .. L. M . de W. Tillekeratne, BSc (Cey), M E d (Calif) .. A . M . Abeysinghe N . L. C. Fernando, BSc (Cey) M . T. Subramanian, BSc (Cey) . . A . C. Perera A D V I S O R Y S E R V I C E L. M . d e W . Tillekeratne, BSc (Cey), M E d (Calif) *R. K. Nathaniel , BSc (Poona) J. V. Sabanayagam, B S A (Toronto), M S c (Guelph) M . K. Vythilingam D . J. M . Hettiarachchi LIBRARY A N D P U B L I C A T I O N S . . . L. H . Fernando, BSc P h D (Lond) R. L. de Silva, BSc (Cey), P h D (Lond), D I C .. . D . J. S. de Silva, BSc (Punjab) A D M I N I S T R A T I O N Act ing Chief Administrative Officer Accountant Accounting Assistant Chief Clerk (Accounts) Senior Accounts Clerk Accounts Clerks Internal Audit Officer Internal Audit Clerk Translator/Instructor Secretary t o the Director Stenographers Clerk Typists Record Clerk Postage Clerk Storekeeper P. Kanapathipillai, BSc (Lond), FSS H . S. Goonewardene, B A (Cey) R. I. Pereira W . J. Samuel M . B. Palies K. D . B. H . Abeygunawardena H . Attanayake G. A . K. P. de Silva K. P. Gunawardene N . M . Jayatilleke S. Kulasabanathan U . C. U n a m b o o w e C. B. Warawita H . C. Wickremasinghe I. Rengaraj N . Satchithananthan C . M . Fernando, B A (Cey) G. A . S. Gunasinghe E . C. C. Brohier S. A . L. H . Fernando T. J. Hallaldeen P. W . Uduwawala S. D . J. J. Vitharnepathirana J. N . Apasinha D . W . Bartholomeuz C. V. R. D . Fonseka V. Kodagoda S. B. Wettewe K . L . de Alwis H . W. Perera I . P . Dissanayake * Working Overseas R E P O R T O F T H E D I R E C T O R L. H. Fernando, BSc, PhD STAFF Dr E. M. Chenery resigned from the post of Director, Tea Research Institute of Ceylon, in July 1968, and was succeeded by Dr L. H. Fernando. Mr J. A. H. Tolhurst, Adviser in Agricultural Chemistry and Agronomy and also Deputy Director, resigned in June 1968. Other senior staff changes were the retirement of Mr A. C. Perera, Chief Administrative Officer, the resignation of Dr A. S. L. Tirimanna (Biochemist) and Mr C. H. Wickremasinghe (Tea Taster), and the promotion of Dr V. S. Kulasegaram and Dr W. M. W. B. Mani- pura to Senior Scientific Staff Grade. Dr R. L. Wickremasinghe, Biochemist, moved to the Low-Country Station, Ratnapura. Dr U. Pethiyagoda was on study leave in the UK and Dr Shanmuganathan in Canada. Dr N. Shanmu- ganathan and Dr R. L. de Silva were invited to present papers at the First International Congress of Plant Pathology and Dr W. Danthanarayana at the 13th International Congress of Entomology in Moscow ; they were unable to attend but their papers were presented. Efforts that were made to recruit staff for research proved unsuccessful, and vacant posts in Technology, Entolomogy and Nematology remained unfilled. This was a serious set back to the conduct of research. The com­ plete list of staff changes is given in Appendix 5. STATIONS St Coombs secured 397,894 lb of made tea from 243 acres ; the yield of 1813 lb per acre was the highest ever recorded in the history of St Coombs. This is indeed an achievement, when it is compared with the yield of 480 lb per acre in 1928, the year the Tea Research Institute purchased St Coombs. The nett sale average of Rs 2.29 in 1968, was above the average of Rs 1.93 for high-grown teas, and the profit on St Coombs was Rs 282,115. St Joachim produced 276,665 lb made tea from 260 acres, a mean yield of 1102 lb per acre. The loss incurred on the working of St Joachim over the last three years, consequent on one-third of the acreage being uprooted for replant­ ing, has now been reduced to Rs 26,152 in 1968. The nett sale average of Rs 1.73 for St Joachim teas was above the average of Rs 1.63 for low-grown teas. The TRI Substation at Kottawa, Talgampola, in the Galle District is now 75 acres in extent, with 35 acres planted in clonal tea. The proceeds from the sale of green leaf covered the full working expenses of this station, including the cost of experiments. A high standard was maintained in the management and development of this station. 9 10 ANNUAL REPORT FOR 1968 A firm decision was taken to purchase 203 acres of tea, patna and scrub land from Agratenne Division of Ury Group, Passara, for the establishment of a research station in lower Uva. Progress was made in the development of this station and the first experiments have already been set down. The Hantane Investment Company transferred 56 acres of land to the . Tea Research Institute in August 1968 for the TRI Mid-Country Station. Substantial progress was made in the development of the Station and in the implementation of an experimental programme. RESEARCH No significant differences in yield were generally found when urea was compared against sulphate of ammonia, even with the usual method of broad­ casting the fertilizer on the surface of moist soil. Loss of nitrogen from urea and precautions that should be taken to minimize these losses were studied and recommendations were made. In a wide range of fertilizer experiments on TRI Stations and commercial estates, responses to nitrogen were evident, but yield increases with the application of phosphate and potash were disappoint­ ing. On the basis of these results, a range of 80 to 200 lb N, 20 lb P 2 0 5 , 40 to 80 lb K 2 0 per acre per year is recommended for seedling tea ; and 240 to 360 lb N, 30 lb P 2 0 & and 90 to 120 lb K 2 6 for VP tea. In young tea, striking res­ ponses to nitrogen, phosphate arid potash have been obtained. T200 con­ tinues to be recommended at 4 oz per plant in the first year and f oz in the second year, these applications being made six times per year. When tea is brought into plucking, a fertilizer such as T700 may be used at about 200 lb N per acre per year until pruning is first done. Zinc sulphate applications up to 20 lb per acre per year have increased yields. Liming has not shown any influence on yield, but has raised the pH of the soil, and is accordingly beneficial where high levels of sulphate of ammonia have increased the acidity of the soil. Mulching has been found effective, particularly in young tea. The mater­ ials used were guatemala, dadap and paddy husk in quantities approaching 20 tons per acre per year. The removal of shade has generally increased the yield of both seedling and clonal tea, but experiments are being continued to determine the consequences of shade removal. Studies on the physiology of growth and of the various cultural operations that influence growth and yield were continued. Nutrient deficiency symptoms were induced and corrected using sand culture techniques in the glass house. Studies on growth and dormancy were pursued. Plant hormones were used to break dormancy and improve growth of tea shoots, and also to increase the number and growth of shoots following pruning. Gramoxone at-J- pint in 50 to 60 gallons water applied once in two months has been widely used on estates to control weeds in tea. Some weeds are not ANNUAL REPORT FOR 1968 11 adequately controlled in this way and higher rates and frequencies of applica­ tion of Gramoxone were found necessary. As this increased costs, other chemi­ cals: were tried either as a substitute or a supplement to Gramoxone. Among these diuron at \ lb per acre was found to control weeds effectively over a period of two months. Alternate round of Gramoxone and diuron are accor­ dingly recommended for trial on estates. -Clones continue to be tested at all TRI Stations. Evaluations of yield, quality, tolerance to pests, diseases and drought have been published in The Ted Quarterly. In addition to the usual method of selecting promising bushes in seedling fields, new clones have also been derived by selection in open-pollinated and hand-pollinated progenies. Attempts were also made to obtain desirable characteristics by the use of irradiated cuttings and seed. Emphasis is now placed on the selection of suitable land for replanting of tea.. It is recommended that shallow, eroded soils with underlying rock close to the surface should always be avoided! On suitable soils, rehabilitation: with Guatemala Grass is not always necessary. Where no rehabilitation is done, adequate measures are necessary for soil and water conservation, and the grow­ ing of a suitable legume between tea rows is advisable. The incorporation of organic matter and top soil in planting holes which should be two ft deep is strongly recommended. Eelworm damage is not necessarily confined to tea at the higher elevations ; more recently poor clonal tea in the mid-and low-country have been found.to be affected by the meadow eelworm, Pratylenchus loosi. Factors associated with the incidence of eelworm appear to be high nitrogen and a low uptake of potash. Variations in soil moisture have been found to affect the results of soil sampling for eelworm, and an attempt is being made to determine the right time for sampling in each district. Experiments comparing the use of a winch against uprooting by hand indicate that although initially the eelworm build-up was lower where winching is done, eventually there was no appreciable difference in the two methods cither in respect of eelworm build-up and pathogenicity or in the subsequent growth of tea. These results indicate that winching alone is not sufficient, unless it is followed by deep forking and exhaustive removal of tea roots. ; The search for eelworm-tolerant clones continues. Of six clones (TRI 2025, 2142, DTI, Mooloya 116, 208 and 241) tested for yield and eelworm tolerance, TRI 2025 appeared to be the best, followed closely by Mooloya 241. Fundamental aspects of research on Poria hypolateritia and other root diseases of tea indicate that only a small quantity of inoculum is required: to infect young tea plants. An attempt is being made to determine whether the quantity of inoculum required varies with the age of the tea bush. It has been found that P.hypolateritia can survive as a saprophyte in tea root segments in fallow soil for as long as four years. Methyl bromide has given excellent 12 ANNUAL REPORT FOR 1968 control of PJiypolateritia in large tea stumps, when applied at the rate of one to two lb per 100;sq. ft of infested soil. This finding suggests that Porta patches can. now be fumigated successfully without digging out the infected stumps. Studies of the effects of soil fumigation with methyl bromide on soil microflora and on the growth of tea and Guatemala Grass continue. Methyl bromide was found to be effective in the control of Charcoal Stump Rot of Tea {JJs- tulina deusta), and Rosellinia arcuata. In the control of Collar and Branch Canker (Phomopsis theae) none of the fungicides tested gave satisfactory control of the disease ; even Santar A failed to live up to an earlier expectation. Information on the selection of clones for replanting areas prone to attack by P. theae was published in the December 1968 issue of The Tea Quarterly. Studies continue on the epidemiology of Blister Blight {Exobasidium ve.xans) and loss of crop. Heptachlor is the only alternative to dieldrin that can be recommended at present in the control of Shot-hole Borer. Heptachlor is effective for a maxi­ mum period of 15 months. For this reason, and because the peak of shot-hole borer build-up was about 18 months after pruning, heptachlor is most effective as a mid-cycle application. Morestan and Kelthane are the best acaricides in the control of Red Spider and Scarlet Mites. A bacterium and a fungus pathogenic to Tea Tortrix were isolated from field populations. These organisms are now being identified. It is found that these reach a peak in the south-west monsoon period and perhaps for this reason: tortrix numbers are less during this period. DDT is the best tortrix killer available at present for use in tea, and a single application of DDT was effective for a period of 2\ months. Moreover, DDT applications did not have any adverse effects on the build-up of the tortrix parasite. Spraying insecticides on the frame, drenching the soil, shoot or root or foliar applications of systemic insecticides were not effective in the control of live wood termites. The only method of control available so far was the protection of the frame from the time of planting by annual applications of heptachlor against Shot-hole Borer. Qualitative and quantitative chemical analyses of different types of tea showed the dissimilarities between green, black and instant teas. Analyses of different parts of the tea bush showed a progressive decrease in polyphenols and amino-acids from the bud to the seventh leaf. Quantitative determinations of protein provided evidence that there were changes in these compounds during the different stages of manufacture, parti­ cularly fermentation. A comparison of the volatile compounds of black tea from St Coombs and St Joachim revealed that linalool and its derivatives, geraniol and cis-jesmone were present in relatively higher concentration in the former than in the latter. Artificial addition of the amino-acid, L-leucine, to tea flush (St Coombs), improved the valuations of the black tea prepared therefrom. Manganese too had a beneficial effect on the valuations, but was detrimental above a certain optimal level. Studies on the metabolism of phosphate have given' interesting results. The study of variations in the microbial populations on tea flush con­ firmed last year's observation that these change with season. An investigation of peroxidases indicated that these enzymes undergo changes during manu­ facture. ANNUAL REPORT FOR 1968 13 The process for up-grading St Joachim tea was adopted to orthodox manufacture methods, and more work is in progress on this project. Re­ search in Technology centred round the application of fiuidized bed techniques to the drying of tea. This project suffered an unfortunate set back when Axia Fans, who were collaborating with the Institute on this project, changed hands. Experiments with the manufacture of Instant Tea were also carried out in collaboration with the Biochemist. The freeze-dried samples of instant tea represented a very considerable improvement on the teas produced earlier by spray-drying techniques. The experimental shipment of tea in polythene liners were hot as favoura­ bly reported on as those in conventional chests on arrival in the UK. CTC teas were manufactured at St Joachim during the early part of the year. These samples found favour with buyers from the UK. A project to manufacture green tea on an experimental basis was also initiated. Special attention has been paid to the design, analyses and interpretation of the field, laboratory and factory experiments by the Statistician. The complexity and magnitude of the work involved has increased so much that it is intended to programme and process the data of some of the standard designs on a computer, the computer time being hired for this purpose. LIBRARY AND PUBLICATIONS Dr E . M . Chehery ceased to function as Senior Editor of the Institute's publications, on his departure from Ceylon on 11th July. Dr L- H. Fernando took over the duties of the Senior Editor, after the departure of Dr Chenery. Dr R. L. de Silva continued to function as Co-editor and continued to over­ look the administration of the Library during the year. Library In October, the library was moved into the building previously occupied by the Administrative Division. The library is now situated in close proximity to the research staff who have ready access to the reference library and the reading room. A revision of the mailing list for the publications of the Institute was undertaken towards the end of the vear, but will only be fully implemented in 1969. Publications Parts I and II of the Annual Report continue to be published as Sessional Papers in Sinhalese, English and Tamil. The sale of the TRI Monograph No. 6 on "Insect and mite pests of tea in Ceylon and their . control" were sufficient to cover the cost of printing. In March, the scheduled number of The Tea Quarterly was not published, but a combined March/June number was published in July. The publication of The Tea Quarterly returned to normal with the September issue. For the first time in the 40 years history xsf the journal, summaries of all articles were published in the official language. The complete list of publications issued by the TRI during the year is given in Appendix 1 and the list of scientific papers from the TRI, published in international journals during the : year is given in Appendix 2.;1 14 ANNUAL REPORT FOR 1968 2 — The Tea Quarterly — Index t o Volume 38 .3 — Annual Report for the year 1966 — Part 1 4 — A n n u a l Report for the year 1967 — Part 2 5 — Sessional Paper N o . 20 — Annual Report for the year 1966 — Part 1 - - Published in Sinhala, Tamil and English 6 — Sessional Paper N o . 2 2 — A n n u a l Report for the year 1967 — Part 2 — Published in Sinhala, Tamil and English 7 — S H A N M U G A N A T H A N , N . (1968). 'Root diseases of tea". Tea R e s s Inst. Ceylon Advisory Pamphlet 2 / 6 6 . 11 pp + 8 col. pi. , 7 A P P E N D I X 2 P A P E R S P R O M T H E T E A R E S E A R C H I N S T I T U T E O F C E Y L O N P U B L I S H E D I N I N T E R N A T I O N A L J O U R N A L S A N D S Y M P O S I A I N 1968 B H A V A N A N D A N , V. P. & M E Y E R , K. (1968). Studies o n keratosulfates. J. :. . biol. Chem. 243 , 1052-1059. "' K E R R , A ; & D E SILVA, R. L. (1968). Epidemiology of tea Blister Blight (Exo- basidium vexans). First International Congress o f Plant Pathology, London. M A C N E I L L , B. H . & S A B A N A Y A G A M , J. V. (1968). The induction of dodine tolerance in Fusarium Oxysporum f. melonis. A technique applicable t o the study of bionomics of soil-borne fungal pathogens. Canad. J. Microbiol. 14, 1262-1263. p h i ; ; : M O R R I S . P . J , KIRT1S1NGHE, D , & S T R I C K L A N D - C O N S T A B L E , R , F . (1968). Retardation of growth of salol crystals in the melt i n capillary tubes. J. Crystal Growth 2 , 97-105. ";' ' S E L V E N D R A N , R. R. & I S H E R W O O D , F . A . (1968). Identification o f guano- sine derivatives o f . D - x y l o s e , D-mannose , D-glucose and D-galactose in tn&un strawberry leaxes. Biochem. J. 105,723-721. .. S H A N M U G A N A T H A N , N . (1968). Studies o n the parasitisnf'and control o f tea root disease fungi in Ceylon. First International Congress o f Plant Pathology, London. S I V A P A L A N , P. (1968). Association of Radopholus similis with decline in young tea fields. Plant Dis. Reptr 5 2 , 528. j - r . W E T T A S I N G H E , D . T. (1968). A preliminary investigation o n the effects o f two plant factors o n simazine toxicity. N inth British Weed Control Conference, London. A P P E N D I X 3 . . , m . „ , B U I L D I N G S C O M P L E T E D D U R I N G 1 9 6 8 The Low-Country Station, Ratnapura : : . ' l V T w o jun ior staff houses n 2 — Three .minor staff quarters, (one double unit and one single unit) - A P P E N D I X 1 P U B L I C A T I O N S I S S U E D BY T H E T E A R E S E A R C H I N S T I T U T E O F C E Y L O N I N 1 9 6 8 1 — The Tea Quarterly — Volume 39 Parts 1 & 2 — March/June 1968 Part 3 — September 1968 Part 4 — December 1968 A N N U A L REPORT FOR 1968 15 A P P E N D I X 4 V I S I T O R S T O T H E TEA R E S E A R C H I N S T I T U T E O F C E Y L O N I N 1968 Mr C. G. Akhurst, Member of the World Bank Mission to Ceylon Mrs Jacqueline Amin , S/S Hope , U S A Sir John Arbuthnot, Chairman, Estates & Agency Co . Ltd, England Mr D . Atmer, Berlin, Germany Mr O. P. Bagaria, Steelsworth (Private) Ltd, Assam, India Mr. J. Bain, James Finlay & Co. Ltd, Culcutta, India Mr A . W. Banwell, Investment/Development, India Mr R. W. Bastian, Consultant, Asian Development Bank, F A O , Rome, Italy Mr K. Baloo , Pierce, Leslie & Co . Ltd, South India D r D . S. Bhatia, Coca-Cola Export Corporation, N e w Delhi , India ~ Mr S. K. Banerjee, James Finlay & Co . Ltd, Calcutta, India Mr C M . Bates, Hentley-on-Thames, England D r L. Bateman, Chairman, Malayan Rubber Fund Board, Kuala Lumpur, Malaysia Mr R. C. Billman, Monsanto Co . , U S A Mr W. D . Brind, Director, Commonwealth Bureau of Soils, Harpenden, England D r A . K. Banerjee, Hoechst Pharmaceuticals Ltd, Bombay, India Mr Alors Benda, Embassy of Czechoslavakia, Co lombo Dr K. Caesar, Germany Mr W. H. W. Coultas, Consultant, Asian Development Bank, India Mr D . G. Coursey, Tropical Products Institute, London, England Mrs A . Custot, General Delegate, Comite Francais du The, France Mr K. d e C o u r e g , Leader of the Indian Tea Machinery Delegation to Ceylon Mr A . D ickson , Standard Tea Co. Ltd, London, England D r G. G. Eichholz. Regional Adviser, International Atomic Energy Agency, Vienna , Mr G. H . Ellis, Engineer, Axia Fans Ltd, Crawley, England Mr D . Elz, U S A D r K. Engelthaler, United Nation's Office in Ceylon Mr N a t k o Erber, C o l o m b o , Ceylon Mr K. H . Ermish, Rhu-Stickstoff A - G , Bochum, Germany Mr A . Faure, Asst General Manager, Ste R. Twining & C o . , France 1 • Mr W . R. Feaver, Cadbury Brothers Ltd, Bournville, England Mr H. Ferguson, James Finlay & Co. Ltd, Glasgow, Scotland Professor J. D . Ferwerda, Agricultural University, Wageningen, Hol land Mr G . M . A . Fuller, Weybridge, England His Excellency the.Governor-General o f Ceylon (Mr W. Gopal lawa, M B E ) and his party : Mr A. B. Elkaduwa, Secretary to H E the Governor-General • - Major A . T. Nugawela , A D C to H E the Governor-General Mr F . C. Pietersz, Government Agent, Nuwara Eliya Mr H . Kobbekaduwa, Deldeniya, Menikdiwela ' - Mr A. V. Ghate , Velsicol-Chemical Corporation, N e w Delhi , India Mr W. C. C. Gorst , George Williamsons Africa Ltd, Nairobi , Kenya • "' •' D r P. O'Hagen, Member of the World Bank Mission to Ceylon Mr R. C. Hampel , Plant Protection Ltd., England Mr A . S. M. Haq , Commercial Secretary, High Commission, for'Pakistan, in 'Cey lon Mr C. J. W. Haines, Brooke Bond Liebig Ltd, London, Eng land . T Miss E . Helton, A U X Provinces Gourmandes, Paris, France . 7..;"' D r R. F . Homer , National Research Development Corporation) England. ' D r P. Horst, Berlin,-Germany - Mr Isamu Itoh,'Mitsui i Norin K K , Tokyo , Japan Mr H. S. Jackson, Chairman, Matheson Bosanquet & C o Ltd,- Coonoor , South India Mrs V. Jakovlic, Professor of the University o f Rijeka, Yugoslavia 7 7_ Mr Jakovlic, Ingra, Yugoslavia The H o n . Major Montague Jayewickrema, MP, Minister of Public Works, Posts & Tele­ communications, Ceylon Mr Bong H. Kay , Leader of the Asian Development Bank team to Ceylon D r G. Kemmler, Bunteh Research Station, Hannover, Germany Mr T o n y K e y , Berks, U K D r A . Kerr, Waite Agricultural Research Institute, South Australia Mr R. W. Kettlewell, Hunting Technical Services Ltd, England D r R. Kincaid, Embassy of the United States of America, N e w Delhi , India Mr A. H . J. Kroon , Agronomist , F A O , Rome, Italy Mr B. Kumaran, Upper Waterfield, South India Mr D . W. Lewis, University o f Oxford, England D r & Mrs D . M . Mackay, East Pakistan Mr Lindsay Mackie, London, England , r.: Mr C. J. L. Madden, Director, Rowe, White & Co. , London , England D r Z. Mathioudakis, Greece Mr J. Maurice, George Will iamson & Co. Ltd, London , England Mr L. R. McCutchen, D o w Chemical N . V . Kuala Lampur, Malaysia Mr D . E. MinshuD, Trade Development Officer, Ceylon Tea Centre, London, England Mr B. M. Mukerjee, Member of the Indian Tea Machinery Delegation 1 to Ceylon 16 A N N U A L REPORT FOR 1968 Commander & Mrs G. R. Muir, James Finlay & Co . Ltd, Glasgow, Scotland Mr T. Murayama, N i p p o n Soda Co . Ltd, Tokyo , Japan Mr. M . M . Muthiah, Chairman, Association of Planters of Madras State, India Mr G.S. Napief-Ford, Somerset, England Mr H. R. Neutatz , Berlin, Germany D r Susumu Nishigaki, National Institute of Agricultural Sciences, Tokyo , Japan Mr B. K. G. Niyogi , Andrew Yule & Co. Ltd, Calcutta, India Mr A . N . Norris , Malayakum Plantations Ltd, South India Mr Jiro Otha, Mitsui Nor in K K , Japan His Excellency the High Commissioner for Pakistan in Ceylon, Mr H. K. Panni Mr R. M . Patel, General Manager, Madhavani Sugar Works Ltd, Uganda Mr L. M . Patel, American Spring & Pressing Works, Pvt Ltd, Bombay. India Mr S. J. Perkins, F M C International, U S A D r H . C. Pereira, L A Divis ion, F A O , R o m e , Italy Mr A . L. Perera, Post-Master General of Ceylon Mr E. Ratcliff, Co-op Tea Society, Glasgow, Scotland Mr J. Reinfrank, Berlin, Germany D r E. Rbchecouste, D u P o n t Far East Inc., Australia Mr V. Romer , Frankfurt/Main, West Germany Mr J. Runner,' President, Comite Francais du The,& Mrs Runner Mr Max I. Salhuteru, Government Estate Group^ West Java, Bandung Mr M. M . A . R. Sameha, Trade Representative for the United Arab Republic in Co lombo Mr E. Schroder, Berlin, Germany Mr N . H . Sethna & Mrs Sethna, Bombay Trading Corporation Ltd, South India Mr W. Y . Sharpe, Malayalam Plantations Ltd, South India Mr Rafael Sison, Project Economist , Asian Development Bank, Bangkok, Thailand Mr C. J. Strachan, General Manager, Ang lo Ceylon & General Estates Co . Ltd, England Mr R . L- Stone-Wigg, The African Highlands Produce Co. Ltd, Kericho, Kenya Sir William & Lady Strath, Piccadilly, London Mr M. S. Sydney-Smith, Geneva, Switzerland The Royal Tea Commission Sir Arthur G. Ranasinha, Kt , C M G , CBE, G C I R H. W. Amarasuriya, Esq R. H . de Mel, Esq D . B . Ellepola, Esq., C B E D r W . R. C. Paul K. P. G. Perera, Esq (Secretary) Mr. Ichiro Tanabe, National Institute o f Agricultural Sciences, Tokyo , Japan Mr & Mrs Robert Tellander, University o f Hawaii , Honolulu, U S A D r R. E. Thompson , Axia Fans Ltd, Crawley, England Mr J. E. M . Turpin, Macneil & Barry Ltd, Calcutta, India Mr Yoshiya Uchida, Adviser under the C o l o m b o Plan in Ceylon D r Vidya Sagar, Agricultural Economist , F A O , R o m e , Italy Mr S. Wakamoto , Tozai Bocki Kaisha, Tokyo , Japan Mr A . J. Watson, Michigan, U S A Prof J. M . Webster, S imon Frazer University, British Columbia, Canada Mr Andrew Wemyss , Sotick Tea Co . Kenya Mr J. H . Wertheirri, O. H . Clapp & Co . Inc, U S A Mr D . R. M. Whitaker, Velsicol International Corporation, Singapore Mr S. K l a u s Wiedemann, Berlin, Germany Mr K. D . Wilde, Embassy of the Federal Republic of Germany in Ceylon Mr W. T. Williams, Mincing Lane, London, England Mr J. R. P. Williams, R o w e White & Co . Ltd, London, England Mr W. T. W o o d m a n , Velsicol International, Singapore Mr David Wyndham-Lewis, London, England A P P E N D I X 5 STAFF C H A N G E S — 1 9 6 8 Appointments Directorate Dr L. H. Fernando, Acting Director from 11.7.68 D r L. H. Fernando, Director from 1.10.68 Senior Staff D r ,P. Sivapalan, Head of the Nemato logy Divis ion from 1.1.68 Mf. iP.Kanapathipi l la i , Act ing Chief Administrative Officer from 1.11.68 ANNUAL REPORT FOR 1968 17 lnltriuttliate Staff Nil Junior Staff Mr R. 1. Pereira, Accounting Assistant from 23 .4 .68 ' Mr M . B. Palies, Senior Accounts Clerk from 9 . 5 . 6 8 Mr S. Jayaratnam, Technical Assistant, Technology Divis ion from 1 4 . 7 . 6 8 Mr K. D . Bandularatne, Technical Assistant, Entomology Divis ion from 1 . 8 . 6 8 Mr R. N . Bopearatchy, Technical Assistant, Plant Pathology Division from J . 8 . 6 8 Mr W. A . B. de Silva, Technical Assistant, Biochemistry Divis ion from 1 . 8 . 6 8 Mr V. Shivanandarajah, Technical Assistant, Nematology Divis ion fromT.'8.'68 Mr A . B. D . Wickremaratne, Technical Assistant, Agricultural Chemistry Divis ion from 1 . 8 . 6 8 Mr K. D . L. Nanayakkara, Accounts Clerk, Low-Country Station from 1 8 . 9 . 6 8 Mr T. R. B. Sally, Chief Clerk, Low-Country Station from 1 . 1 1 . 6 8 Minor Staff Mr K. C. W. M. A . Chandrasekera, Laboratory Attendant, Plant Pathology Divis ion from 1 . 9 . 6 8 Resignations Mr B. P. Jones, Stenographer/Typist/Clerk from 3 1 . 3 . 6 8 Mr G. T. Karunasena, Laboratory Attendant, Plant Pathology Divis ion from 3 1 . 3 . 6 8 Mr W. R. F . Rodrigo, Technical Assistant, Plant Pathology Divis ion from 2 8 . 5 . 6 8 Mr M . Sikurajapathy, Technical Assistant, Agricultural Chemistry Divis ion from 3 0 . 5 . 6 8 Mr J. A . H . Tolhurst, Deputy Director and Adviser in Agricultural Chemistry and Agrono­ my from 6 . 6 . 6 8 Mr H. B. Herath, Technical Assistant, Entomology Divis ion from 1 5 . 6 . 6 8 D r E . M. Chenery, Director from 1 0 . 7 . 6 8 Mr A . Nanayakkara, Technical Assistant, Plant Physiology Divis ion from 3 1 . 8 . 6 8 Mr K. C. W. M . A. Chandrasekera, Laboratory Attendant,. Plant Pathology Division from 2 . 1 0 . 6 8 Dr A . S. L. Tirimanna, Biochemist (Flavour Research) from 3 1 . 1 0 . 6 8 Mr K. D . L. Nanayakkara, Accounts Clerk, Low-Country Station from 2 0 . 1 1 . 6 8 Mr U . P. de S. Waidyanatha, Technical Asistant, Low-Country Station from 30.11 63 Retirements Mr A. H. B. Dias , Accounting Assistant from 3 1 . 3 . 6 8 Mr A. C. Perera, Chief Adminstrative Officer from 3 1 . 1 0 . 6 S Termination of Services Mr D . W. Wickremaratne, Accounts Clerk from 1 7 . 1 0 . 6 8 Overseas Training Arrivals Mr J. V. Sabanayagam, Advisory Officer, Low-Country Station returned after post-graduate training from Canada o n 6 . 6 . 6 8 . . . . . . . . . . D r N . Shanmuganathan, Plant Pathologist, returned after post-doctoral research from Canada on 2 . 1 0 . 6 8 Mr K. Sivapalan, Technical Assistant, Biochemistry Divis ion, returned after post-graduate training from India on 1 5 . 1 0 . 6 8 Dr R. R. Selvendran, Research Officer, Biochemistry Divis ion, returned after post-graduate training from the U K on 2 3 . 1 0 . 6 8 . Departures Dr U. Pethiyagoda, Plant Physiologist, was awarded a Nuffield Foundat ion Fellowship for post-doctoral research in the U K and'left Ceylon o n 5 . 3 . 6 8 Mr R. K. Nathaniel , Advisory Officer, was awarded a C o l o m b o Plan Scholarship for - post­ graduate training in Canada and left Ceylon on 2 3 . 8 . 6 8 Mr N . M. Abdul Gaffar, Research Assistant, Technology Divis ion, was awarded a Co lombo Plan Scholarship for post-graduate training in the U K and left Ceylon o n 2 6 . 9 . 6 8 Mr S.' Sandanam, Research Assistant, Agricultural Chemistry Divis ion, was awarded a C o l o m b o Plan Scholarship for post-graduate training in the U K and left Ceylon on REPORT OF THE AGRICULTURAL CHEMISTRY DIVISION Agricultural Chemist — V. P. Bhavanandan, BSc, PhD, ARIC General Mr J. A. H. Tolhurst left Ceylon in June after serving the Tea Research Institute for fifteen years as Agricultural Chemist. Mr S. Sandanam pro­ ceeded to the United Kingdom in September for his postgraduate training. Mir S. Sivasubramaniam continued his training at the Rothamsted Experi­ mental Station. Mr M. Sikurajapathy, Technical Assistant, resigned from his post on 30th May and was replaced by Mr A. D. P. Wickremaratne on 1st August. Laboratory Investigations Chemical and physical analyses of soils The aim of this investigation.is to compare the chemical status of soils from the different tea districts of Ceylon. Soils from tea fields and undisturbed jungle soils from St Coombs, St Joachim, Hantane, Passara and. Kottawa are being analysed for the following physical and chemical properties : texture, colour, pH, organic carbon, nitrogen, acid soluble K & P, cation exchange capacity, exchangeable cations (potassium, calcium, magnesium, sodium) and the more important trace elements. After reviewing the results of these analyses the survey will be extended to other districts, if this is considered worthwhile. It is hoped that the results of such a survey will help in advising estates regarding their fertilizer programmes and also in interpreting and comparing the results from the fertilizer extension experiments in different districts. T. C. Z . Jayman Correlation between leaf and soil manganese The objective of this experiment is to find the best method for estimating plant-available manganese in the soil. Soils from fourteen plots of a shade experiment at the Mid-Country Station were analysed for total manganese and for extractable manganese using the following three extractants: Morgan's (pH 4.8), ammonium acetate (pH 7.6) and ammonium acetate-quinol. Leaves from the same plots were also analysed for total manganese. Statistical analysis of the results showed that the leaf manganese values could not be correlated with any of the four values obtained for the soils. The search for the correct extractant will be continued. The results from this experiment will be very useful in view of the finding that leaf manganese plays an important role in the development of flavour (Wickremasinghe, Perera and de Silva 1969). T. C. Z. Jayman Ammonium nitrogen vs nitrate nitrogen for tea in sand culutre In order to investigate whether tea prefers ammonium or nitrate notrogen two sets of tea plants of clone DT 1 were established in sand culture. After the plants were growing actively, one set of plants was given a balanced nu­ trient solution containing sulphate of ammonia labelled With N 1 5 as the only source of nitrogen. The second set of plants was also given the balance nutrient solution but containing potassium nitrate labelled with N 1 5 as its only source of nitrogen. At the end of ten weeks, two plants from each set 18 ANNUAL REPORT FOR 1968 19 were separately fractionated into the following components: ammonium amide; nitrate; caffaine; amino acids and protein (residue). The individual components were digested with sulphuric acid and hydrogen peroxide. After determination of total nitrogen, the digests were sent to the IAEA laboratories in Vienna for analysis of percentage excess N 1 8 . The results indicated that under the conditions of this experiment, young tea plants of clone DT 1 were able to assimilate both forms of nitrogen. It is intended to pursue these studies after some arrangements are made for the N 1 5 analysis, and when more of the expensive N 1 5 compounds can be purchased. It is necessary to carry out similar experiments in soils, firstly in pots and later in the field. The behaviour of the tea plants growing in soil might be different from those growing in sand culture because of the importance of pH for the growth of tea and the difficulty in controlling pH in sand-culture experiments. T. Kularatna pH and the growth of tea It is well known that nitrification occurs readily in soils of high pH. It is, therefore, reasonable to expect that the ammonium content of soils with high pH will be low in comparison to that of the soils with low pH. This experiment is designed to find out whether there is a relation between the poor growth of tea plants in soils with high pH and the absence of ammonium nitrogen in these soils. Tea plants of clone TRI 2025 were planted in four sets of ten pots each, filled with treated soils, as follows: 1st set — Soil adjusted to pH 7.2 with Limbux 2nd set — Soil adjusted to pH 7.2 with Limbux, mixed with N-Serve* at 5 ppm and then fumigated with methyl bromide to minimize nitrification 3rd set — Soil adjusted to pH 7.2 with Limbux 4th set — Soil pH 5.2, mixed with N-Serve at 5ppm and fumi­ gated with methyl bromide. Some difficulties are being experienced in establishing the young plants in the pots. The growth is generally poor, most plants developed a scorch and a few died. The dead ones have been replaced and after they are well estab­ lished, the 1st, 2nd and 4th sets will be given 10 g of T 200 fertilizer mixture per year in four applications every three months. The third set will receive the corresponding quantity of T 200 without the ammonium sulphate in the same number of applications. The ammonium sulphate for this set will be given separately as a solution, in weekly applications. If the experiment is successful, the effect of high pH and rapid nitrification on the growth of tea plant can be compared with the effect of high pH alone, with nitrification inhibited. Further, from set 3 the effect of frequent appli­ cations of ammonium nitrogen to tea plants growing in soil of high pH can be assessed. An attempt is also being made to duplicate this experiment using soil with a naturally high pH (7.2). In this experiment aluminium sulphate will be used to decrease the pH of the soil required for the 4th treatment. T. Kularatna * N-Serve (2-cM6ro-6-trichlonnethyl pyridine) is a compound marketed by the D o w Chemi­ cal Co. , U S A , and is k n o w n to inhibit nitrification when mixed with soil; 20 ANNUAL REPORT FOR 1968 Studies on the- enzyme urease The. enzyme urease hydrolyses urea applied to the soil to ammonium carbonate, thereby making the nitrogen available to plants. This enzyme has also been detected in certain plants. It was detected in the fleshy tea roots and in tea flush. On an average, the enzyme present in 100 g of flush released about 60 mg N as ammonia from urea, under optimal conditions. In addition to this enzymatic conversion of urea to ammonia, a high degree of non-enzy­ matic hydrolysis of urea was noticed in the boiled tea flush homogenates. Urease in tea soils The urease activity of the soil is important for the utilization of urea applied to the soil as fertilizer. This enzyme is usually present in large quanti­ ties in biologically active soils, because microorganisms hydrolyse urea enzyma- tically. In experiments with St Coombs soils the following information was obtained : 1 — The urease activity of tea soils, as in other soils, is of two types : (a) extracellular activity, adsorbed on soil colloids and humi­ fied organic matter, and (b) activity caused by the metabolizing ureolytic micro­ organisms. Both types are almost completely destroyed on autoclaving the soil; the second type can be selectively inhibited by the addition of toluene. 2 — The urease activity in the soil decreases with depth. eg Depth in inches 0-6 6-12 12-18 18-24 Urease number* 39.6 23.7 14.8 13.9 3 — It appears that the application of urea to the soil increases the urease activity of the soil, as shown below: Treatments Urease Number (Soils from Experiment A4) (Average of 8 determinations over 2 months) Urea 37.7 Calcium ammonium nitrate 28.6 Sulphate of ammonia 21.3 Urease and copper inhibition In this experiment, the inhibition of urease activity in the soil by copper (as copper sulphate & Perenox) was investigated. It was found that large quantities of copper inhibited the activity of this enzyme, eg 500 ppm of copper added to the soil caused a 19% inhibition of the urease activity. The urease activity of the soils from the Plant Pathology Experiment P26 were examined * The urease number gives the quantity o f urease contained in 100 g soi l , eg Urease number 1 corresponds to the quantity o f enzyme in 100 g soil: which hydrolyses 1 m g of nitrogen as a mmcnia from urea, under the specified conditions. . . ANNUAL REPORT FOR 1968 21 to investigate whether the Perenox used for blister blight control has any effect on the urease activity of the soil. The plots in this experiment received six doses of Perenox (0, £, 1, 2,4 and 8 oz per acre) at weekly intervals for three years. There was no satistically significant difference in the urease activity between the six treatments. Urease and soil fumigation with methyl bromide It is known that fumigation of soil with methyl bromide destroys a wide variety of microorganisms normally present in the soil. Investigations showed that the urease activity of the soils fumigated with methyl bromide at 1 lb and 4 lb per 100 sq. ft decreased to 60% and 45% respectively, of the original value, one week after fumigation. It was further noted that even after 11 weeks of fumigation the urease activity did not reach the original value. V. Fernando Volatilization losses from urea applied to the soil Some of the urea applied to the soil may bz lost by volatilization of ammonia after the urea is converted to ammonium carbonate by the enzyme urease. The degree of loss will depend on the properties of the soil as well as on weather conditions. Some of the factors affecting these losses are pH, cation exchange capacity, moisture content, temperature, rainfall and sunshine patterns. Some preliminary studies carried out on this problem gave the following information : 1 — The percentage losses of nitrogen from urea, sulphate of ammonia and calcium ammonium nitrate broadcast on soft was measured in different locations at St Coombs. The figures are given below: Treatment Loss of nitrogen into the atompshere (%) Location No. 1 2 3 4 Urea 33.0 10.7 39.9 24.6 Ammonium sulphate 4.7 3.8 4.5 0.2 Calcium ammonium nitrate 1.8 3.7 2.9 0.4 2 — In most experiments, the losses from urea reached a maximum between the third and fourth days after application and was negligi­ ble after about three weeks. The results under very dry condi­ tions may be different. 3 — The quantity of nitrogen lost was proportional to the rate of appli­ cation of urea : Dose of urea Nitrogen lost as ammonia (lb N per acre) (%) 125 8.9 100 6.9 75 2.7 50 2.0 The figures are from only one experiment; the absolute values do not, therefore, mean much. 22 ANNUAL REPORT FOR 1968 4 — Different methods of application of urea in the field were investi­ gated in order to minimize volatilization losses. The following is the approximate order of efficacy of the methods tested, as com­ pared with broadcasting: (a) Burying of urea to a depth of 3 in.; deep forking-in of urea; injection of urea solution to depths of 4J in. and 6 in. (b) Broadcast followed by spraying of water—simulated rain­ fall (see below). (c) Spraying of urea solution on soil. (d) Dibbling in of urea using hand forks. In a typical simulated-rainfall experiment the figures given below were obtained. Simulated rainfall (inches) N lost as ammonia (%) 0.1 0.2 0.3 0.5 Field Experiments A7, A14 and A17 are being initiated to extend this investigation on the efficiency of the methods of application of urea on an estate scale. V. Fernando Studies on the leaching properties of area The movement of urea in soil in relation to ammonium and nitrate ions was studied using chromatographic columns packed with fresh soil from the field. The results indicated that urea was partly retarded in comparison to nitrate ions which emerged right away from the column. In comparison, however, ammonium ions were eluted only slowly and continuously. It is, therefore, possible that urea is held by some weak adsorption forces on to the soil colloids. An experiment is being planned to study the leaching of urea under field conditions. V. Fernando Fertilizer mixtures and nitrogen losses The strong odour of ammonia which emanated from some of the fertilizer mixtures that were' being handled by us prompted an investigation into the losses of nitrogen as ammonia from fertilizer mixtures. Some initial experi­ ments indicate that fertilizer mixtures consisting of sulphate of ammonia and sapho'sphbsphate slowly and uniformly lost nitrogen as ammonia. Over a period of 38 days a mixture of sulphate of ammonia and saphosphosphate lost 4.9 % of its nitrogen as ammonia. Addition of muriate of potash to the above mixture did not prevent the loss of ammonia. Losses from mixtures where sulphate of ammonia was substituted by urea were negligible (less than 0.1%). Further investigation is necessary to determine the causes for these losses. It is possible that some substance in saphosphosphate may be responsible. 2.2 0.7 0.5 0.2 T . Kularatna ANNUAL REPORT FOR 1968 23 Field Experiments and Trials Experiment A l l was abandoned. Al — NPK at No. 3 Field, St Coombs — (1931) Yield response for the first and second years of the 12th cycle are shown in Table 1. TABLE 1 — Yield response for the first and second years of the \2ih year cycle N P 3 O s K a O Treatments • First year Second year (lb per acre per annum) 0 b per acre per annum) (lb per acre per a m 120 697 942 180 688 1029 240 728 1126 0 575 889 30 798 1134 60 740 1075 0 382 542 75 884 1273 150 847 1283 P = 0 . 05 85 112 P = 0 . 01 115 152 P = 0 .001 153 201 There was no significant response to nitrogen during the first year of the 12th cycle but in the second year, nitrogen gave a significant response. A highly significant rseponse to 30 lb P 2 0 5 was obtained for both first and se­ cond years but there was no further response to an additional 30 lb P2O5. Similarly, for K a O the response to 75 lb was marked in the first and second years with no further increase in response to an additional 75 lb K a O. A2 — NPZn, lime at No. 9 Field, St Coombs — (1962) Liming treatments were introduced into this experiment in the second cycle. Details of treatments in the second cycle were given in the Annual Report Yield potential of VP tea The yield potential as well as the other characteristics of a plant are in­ herent in the plant and will depend on one or more factors. If in the case of VP tea it is possible to determine factors controlling its yield potential, then it would be easier to predict the yield that a particular clone is capable of giving than it is at present. The yielding capabilities of clones are now assessed by long-term (several cycle) and tedious field experiments. It is reported (Chirarijeevi Rao, Krishnamurthy & Thuljaram Rao 1967), that the yield potential of sugar cane varieties can be correlated with the cation-exchange capacity of the sett roots. Investigations were initiated to determine whether such a relation existed in the case of VP tea. Young tea plants of clones of widely differing and known yield potentials were selected for this study. After the methods are worked out, the cation-exchange capa­ cities of the feeder roots of these clones will be determined to see whether these values have any correlation with the yield characteristics of each clone. S. Kulasegeram & A . D . P. Wickremaratne 2 4 ANNUAL REPORT FOR 1968 for 1966. The summarized results for the first 24 months of the second cycle are given in Table 2. Results were analysed separately for replicate 1 and repli­ cate 2 because the lime treatments given to each replicate varied. TABLE 2 — Yield response for the first 24 months of the second cycle Treatments (lb per acre per annum) Yield (lb per acre per annum) Replicate 1 Replicate 2 N 150 2767 2771 300 2988 3002 450 2980 3052 ZnSOa 0 2813 2759 10 2828 2894 20 3094 3172 L S D P = 0 . 0 5 168 177 There was no significant response to the phosphate and liming treatments. Response to both nitrogen and zinc sulphate was linear and significant. A detailed examination of soil pH was carried out at two depths in December 1968 and the results are presented in Table 3. TABLE 3 — Effects of nitrogen and liming treatments on soil pH at two depths Soil depth (inches) 0 — 6 L S D (P = 0 . 0 5 ) 6 — 12 L S D (J> - 0 . 0 5 ) Replicate—1 N (lb per acre per annum) Replicate—2 N (lb per acre per annum) • 150 4 . 2 3 4 . 2 2 300 3 . 8 6 3 . 9 3 450 3 . 7 9 0 . 1 1 3 . 8 7 0 . 0 8 150 4 . 3 7 4 . 4 3 300 4 . 0 6 4 . 1 7 450 3 .9S 0 . 1 3 4 . 0 7 0 . 1 4 Lime (tons per acre)* n 1 0 3 .88 Lime (tons per acre)* 0 2 3 .96 0 — 6 L S D (P — 0 . 0 5 ) 6 — 1 2 L S D (P = 0 . 0 5 ) *On1y one application of l ime was given at the beginning of the cycle. 3 . 9 5 4 . 0 4 0 . 0 5 4 . 0 7 0 . 0 5 4 . 0 7 4 . 3 1 0 . 0 8 4 . 3 8 0 .09 There was a marked decrease in pH with increasing levels of nitrogen at the two soil depths examined. . The application of one ton of lime had a small but a significant effect on soil pH at both depths. With two tons of lime per acre soil pH was raised markedly at both depths. A8 — NPK on clone TRI 2024 at No. 8 Field, St Coombs — (1962) After the first prune in September 1967, the plots were brought into plucking in March 1968. Levels of nutrients tested in the second cycle are the same as for the last year of first cycle! Yield data for the first year after pruning ANNUAL REPORT FOR 1968 '25 were > analysed and the results are presented in Table 4. As in the previous cycle, the results were summarized for the two groups of blocks separately. Group 1 gives markedly higher yields than Group 2. TABLE 4 — Yield response for the first year of second cycle Group 1 Group 2 Treatments Yield Yield (lb per acre per annum) (lb per acre per annum) (lb per acre per annum) N 100 1251 953 200 1413 1221 300 1406 1089 P , 0 5 0 1387 : 1141 50 1320 . 1148 100 1361 975 K , 0 0 1364 1052 6 2 . 5 1394 1061 125 1312 1150 Mean for control plots 638 448 L S D (P = 0 . 0 5 ) 58 165 Response to fertilizer levels was generally small during the first year of the second cycle. In Group 1 where the yield levels are high, there was a significant response up to 200 lb N but no further increase in yield with 300 lb N. Similar trends were also evident for nitrogen in Group 2. There were no consistent trends in the response to phosphate and potash in either group. A10 — Ar, K on clone E 727 at Walaha, Tangakelle Group, Lindula — (1965) After the pruning in June 1967, the plots were brought into plucking in November 1967. Out of the 54 plots laid out originally 36 plots were selected for the fertilizer trial. This design is of the split-plot type, nitrogen being applied to the main plots and levels of potash to the subplots; there are four replicates. Nutrient levels tested are: N (lb per acre per annum) 200 300 400 K 2 0 (lb per acre per annum) 0 75 150 The first treatments were given in May 1968 and no yield analysis will b e made at this early stage of the experiment. A12 — NPK at No. 3 Field St Coombs — (1966) The plots were pruned in July 1968. A complete statistical analysis of the results was carried out for the yield totals of the first cycle (27 months only). The summarized results are presented in Table 5. TABLE 5 — Yield totals for 27 months of the first cycle Nitrogen Yield K 2 0 Yield (lb per acre per annum) (lb per acre) (lb per acre per annum) (lb per acre) 90 2323 0 3582 180 3231 75 3708 270 3955 150 3867 360 4393 '. — — 450 4693 — . • — L S D (P = 0 .05) 517 224 26 ANNUAL REPORT FOR 1968 There was a marked response to levels of nitrogen though the yield'in­ crements due to nitrogen beyond 270 lb N tended to be small. Both the linear and quadratic effects of N were, therefore, very highly significant. No response to phosphorus has yet been observed in this experiment but a signi­ ficant response to potassium was obtained at the 5% level of probability. W. B. Manipura, A. D . P. Wickremaratne & S. G. Jayasuriya MAI — Nitrogen, potassium and shade on seedling tea at Hantane Estate, Kandy — (1966) This experiment is decribed in the Report on the Mid-Country Station (see page 148). Field experiments with urea A4 — Type of nitrogen at No. 9 Field —(1961) In this new cycle the treatments, viz sulphate of ammonia, urea and cal­ cium ammonium nitrate at two levels of N (150 and 300 lb per acre), remain unchanged. The tea was tipped and brought into plucking on 21st January 1968. In the first year (eight plucking months) of this cycle there was no statistically significant difference in yield either for the types or for the levels of nitrogen. S. Sundaralingam A5 — Frequency of application of nitrogen at No. 13 Field — (1963) In this second experimental cycle, sulphate of ammonia was replaced by urea. The tea was tipped and brought into plucking on 11th February 1968. The levels of nitrogen (120 and 240 lb per acre) were maintained throughout, but the frequency (2,3 and 4 applications per year) was reintroduced only from September of this year. For the period ending August 1968, there was no significant difference in yield for the levels of nitrogen. S. Sundaralingam Al — Nitrogen distribution at No. 13 Field — (1963) Again, in the new cycle urea was substituted for sulphate of ammonia. The tea was tipped and brought into plucking on 11th February 1968. From December a new treatment, namely methods of application, was introduced in this experiment to study the effect of forking in of urea. The present treat­ ments, therefore, consist of a) — two levels of urea (75 and 225 lb N per acre) b) — two methods of distribution of urea (alternate and double row) c) — two methods of applications of urea (broadcast and forking in) replicated four times in randomized blocks. The results upto the end of November, ie before the introduction of the new factor, were statistically analysed. The difference in yield between the two levels of nitrogen is significant at the 1 % level of probability. As in pre­ vious years, there was no significant difference in yield between the two me­ thods of distribution of nitrogen. S. Sundaralingam ANNUAL REPORT FOR 1968 27 A14 — 3 levels of nitrogen {urea), 3 levels of potassium, 7> frequencies of appli­ cation and 3 methods of application of urea on VP tea at TangakeUe Group, Lindula — (1967) The 81 treatment combinations were allocated to the plots and the pre- treatment yield data analysed to check for inherent variations. The treatments will start early in 1969. 1968 Experiments A17 — 3 levels of urea and 3 methods of application on VP tea at No. 8 & No. 16 Fields — 3 x 3 randomized block design replicated 3 times — (1968) Thirty plots were laid out in three different clonal areas and pre-treatment yields are being recorded. Treatments will start early in 1969. A22 — Damage to tea leaves resulting from foliar applications of urea — (1968) In order to find the optimum concentration of urea solution that can be sprayed on tea foliage without damaging the bush, a few observation trials were carried out. It was found that urea solutions upto 3 % concentration at the rate of about 100 ml per bush sprayed with a knapsack sprayer did not cause visible damage to the bush. A 4% urea solution at the above rate caused some slight scorch on the foliage; the scorch was reduced considerably when a spreader like Teepol was added to the solution before spraying. Solutions of 5 and 10 % con­ centrations were found to induce scorch the latter, rather severely. An experiment is being planned to compare the efficacy, with regard to crop increase, of knapsack spraying and mistblowing of urea solutions on mature Experiments on spacing and bringing into bearing A9 — Clonal spacing at Nos 2 and! Fields, St Coombs — (1964) This experiment continues to get uniform fertilizer treatment in order to evaluate the residual effects of the NPK mixture (T 200) applied during the first 16. months from planting. Table 6 shows the yield trends for the 4th year from planting, ending in July 1968. Figures under 'Initial N treatment' refer to nitrogen equivalent of the initial 15-month-treatment; all plots have since received 240 lb N per acre per annum. Residual effects of the initial fertilizer levels were still evident. TABLE 6 — Residual effect of varying levels of T 200 in the first 15 months from planting — 4th year yields • — A9 — St Coombs M. Sikurajapathy & C. C. Rajasingham S. Sundaralingam tea. S. Sundaralingam Initial N treatment ( l b / acre ) Present N treatment ( l b / a c r e ) Yields ( l b / a c r e ) 1 6 . 6 240 1672 8 3 . 3 240 1832 1 5 0 . 0 240 1979 L S D (P = 0 . 0 5 ) 159 28 ANNUAL REPORT FOR 1968 Table 7 shows the effect of clone and spacing treatments tested in this experiment. TABLE 7 Yield from clones spaced differently for the 4th year Clone Yield (lb per acre per annum) T R I 2 0 2 4 2088 D T 1 1854 TRI 777 1541 Spacing 14 1893 28 .1799 42 1791 L S D (P = 0 .05 ) 159 L S D (P = 0 . 0 1 ) 214 Spacing indicated in the Table are distances between plants in the row, rows being four ft apart. Clonal differences are still marked but the yield differences resulting from varying the spacing were not significant. A15 — Bringing-into-bearing and spacing of VP tea at No. 3 Field, St Coombs — (1967) The methods of bringing-into-bearing being tested in this experiment are: 1 — Two bendings followed by cutting across at 14 in. and tipped at 18 to 21 in. and brought into plucking, 2 — Cut at six in., then at 14 in. and tipped at 18 to 21 in. and brought into plucking, 3 — Cutting at six in. followed by bending of the axillary branches. New shoots are cut at 14 in. and tipped at 18 to 21 in. and brought into plucking. These treatments are studied in relation to three clones, DT 1, TRI 2142 and TRI 2025, and three spacing viz 10i, 21 and 42 inches within the row, the rows being four ft apart. The initial bending and cut-across treatments were given in December 1967. There were many casulaties during the drought in early 1968. Analysis of variance was carried out on the percentage deaths (data transformed before analysis) and the summarized results are shown in Table 8. TABLE 8 — Effect of spacing and bringing-into-bearing treat­ ments on percentage deaths of different clones during the drought in early 1968 Clone % deaths Trnasformed data D T I 9 . 5 17 .92 T R I 2142 1.7 7 .37 T R I 2025 8 . 9 17 .40 Spacing (inches) . 10J 6 .3 14 .54 21 5 .7 13 .79 42 6 .1 14 .34 ' Method of bringing-into-bearing Bent only . 1.1 6 . 0 6 Cut only 1 0 . 9 19 .24 Cut and bent , 8 . 9 17.38 L S D (J> = 0 .05 ) — 2 . 1 0 (P = 0 . 0 1 ) — 2 . 8 3 (P = 0 .001) — 3 . 7 6 A N N U A L REPORT FOR 1968 29 Clones DT 1 and TRI 2025 were adversely affected by. the drought, this effect being mainly because of the poor conditions of the nursery plants of these two clones. When the plants were cut at six in. there were only a few leaves remaining on the plant. The two cutting treatments, therefore, resulted in a greater number of casualties than those from the bending treatment. Spacing had no significant effect on percentage deaths. This experiment will be brought into plucking in July 1969. W. B. Manipura, S. Sandanam & S. C . Jayasuriya Shade experiments A13 — 3 levels N on 3 clones with 3 levels of shade at No. 3 Field — (1966) The experiment was planted out in July 1968. The three levels of shade are: no shade, Acacia pruinosa spaced 24 ft x 24 ft, and 24 ft x 12 ft apart. Three clones, TRI 2142, TRI 2025 and TC 9, and three levels of N are allocated to the subplots within the shade treatments; there are three replicates. Uniform fertilizer (T 200) will be given for the first two years. At the end of this period the nitrogen treatments will be applied. UA2 — 3 levels of shade, 3 methods of bringing-into-bearing on 5 clones at the Agratenne Substation — (1966) The plots were demarcated and tea was planted in November 1968. No results are available. . W. B. Manipura &' S. G. Jayasuriya Rehabilitation experiments A16 — Rehabilitation Experiment Nos 11 and 13 Fields — (1967) A second set of blocks of old tea was uprooted and planted in Guatemala grass in August 1968. It is proposed to plant VP tea in all blocks in July 1969. ] 968 Experiments A18 — Guatemala grass (Tripsacum laxum), Mana grass (Cymbopogon : confertiflorus) and Crotolaria anagyroides each at 3 levels of nitrogen as soil rehabilitation crops at No. 5 Field — 4 replicates of 9 treatments in randomized blocks — (1968) The three rehabilitation crops were planted in an old-tea area which was uprooted in July 1968. The growth of the three crops are being studied at 3 levels of N. The results are not yet available. A19 — Rehabilitation vs none at No. 3 Field — Paired plots — (1968) Fifteen pairs of plots were marked out in two adjoining areas; 15 plots, on land rehabilitated with Guatemala grass for two years, and the other 15 plots on land where the old tea was uprooted in April 1968, with no subsequent rehabilitation. The plots which were not rehabilitated, ;were fumigated with methyl bromide at the rate of \ lb per 100 sq. ft. All plots were planted with clone TC 9 in June 1968. Apart from the excellent weed control obtained in the fumigated piots till the end of the year, no differences in the growth of tea can still be observed visually between the two treatments.- Soil samples were taken in July 1968 at a depth of 0 to 6 in. and chemical analyses were carried out. The results obtained are summarized in.3%ble;9... ; 30 ANNUAL REPORT FOR 1968 TABLE 9 — Soil nutrient status — 0 to 6 in. depth A m m o n i u m Nitrate Total Available Exchange- Carbon p H Treatment nitrogen nitrogen nitrogen phosphorus able potassium (ppm) (ppm) (%) (ppm) ( % m e q ) (%) 2 yerars rehabilitation 2 4 . 2 1.29 0 . 2 7 1 3 . 3 0 . 5 9 3 . 0 3 5 . 2 N o rehabilitation 3 1 . 3 0 . 9 8 0 . 2 4 9 . 9 0 . 3 7 2 . 6 6 5 . 0 (Fumigated) ** N S * N S N S — not significant » — significant at P < 0 .05 ** — significant at P<0.01 ati *** — significant at P< 0 .001 Plots which were not rehabilitated but fumigated with methyl bromide gave a higher content of ammonium nitrogen than plots rehabilitated for two years. Increase in the ammonium nitrogen content after fumigation has been reported previously (Shanmuganathan & Fernando 1967). Percentage total nitrogen, percentage organic carbon, exchangeable K, and pH were slightly higher in the rehabilitated plots than in the fumigated plots. Further studies on soil physical structure, chemical characteristics and growth of plants are planned. W. B. Manipura, S. G. Jayasuriya & A. Somaratne Young tea experiments Experiments AYT12, AYT14, AYT15, AYT16, AYT19 and AYT20 have been concluded. AYT21 was abandoned. AYT22 and AYT23 are reported as A20 and A21 respectively. A20/— Mulching on young tea at No. 3 Field — (1967) This experiment compares mulching with Guatemala loppings once a year and twice a year at the rate of 16 tons fresh material per acre each time with no mulching. The effect of mulching on growth, soil moisture content, soil nutrient content and weed growth are being studied. Growth of the young tea was assessed at the end of one year by cutting the plants across at nine inches. Summarized results for the leaf and stem weights and for total dry weight per plant are shown in Table 10. TABLE 10 — Effect of mulching with Guatemala grass on the growth of young tea Treatment Leaf dry wt Stem dry wt Total dry wt (g per plant) (g per plant) (g per plant) Mulched once a year 4 3 . 6 2 7 . 2 7 0 . 8 Mulched twice a year 4 2 . 3 2 4 . 9 67 .1 Control 3 5 . 6 2 0 . 4 5 6 . 0 L S D (P = 0 .05 ) 6 . 3 4 . 3 10 .5 Leaf dry weight, stem dry weight and total dry weight per plant were significantly increased by mulching once a year when compared with no mul­ ching, but mulching twice a year did not result in any further increase in ANNUAL REPORT FOR 1968 31 growth. Mulching also resulted in slightly higher moisture content of the soil mostly at 0 to 6 in. depth. Chemical analysis of soil carried out at the end of the first year did not show marked differences in available nitrogen, total nitrogen, available phosphorus and exchangeable potassium between the treatments tested. Preliminary studies on the effect of mulching on surface runoff, infiltration and soil erosion are being made in similar experiments. The results are not yet available. (Refer under AIT22 in previous Annual Reports). A21 — Sulphate of ammonia, calcium ammonium nitrate and urea on 3 clones — (1967) Sulphate of ammonia, calcium ammonium nitrate and urea were tested as a source of nitrogen for young plants on three clones TC 9, DT 1 and TRI 2027. Surface application of these fertilizers was also compared with dibbling and no dibbling as sub-treatments. The quantity of fertilizer applied was equi­ valent to 90 lb nitrogen per acre per annum on the basis of 5000 plants per acre. Fertilizer was always applied in wet weather. At the end of first year plants were uprooted and the dry weight of leaf, stem and roots were taken separately. The summarized results for the effect of the type of nitrogen on growth ate shown in Table 11. TABLE 11—Effect of the type of nitrogen on the growth of young tea Treatment • Leaf dry wt Stem dry wt R o o t dry wt (g per plant) (g per plant) (g per plant) Sulphate o f ammonia Clacium ammonium nitrate Urea N o nitrogen L S D (J> = 0 .05 ) All three types of nitrogen gave similar and significant increases in leaf dry weight per plant and stem dry weight per plant when compared with the control. Increase in root dry weight per plant failed to reach significance at the 5 % level of probability. There were no significant differences in leaf, stem and root dry weights between types of nitrogen and between dibbling and no dibbling. There was no interaction between clones and type of nitrogen with respect to any of the yield components. (Refer under AYT23 in previous Annual Reports). W. B. Manipura, A . Somaratne & S. G. Jayasuriya, Chemical control of weeds Experiments Wl, W2, W6, W7, W9 and W10 have been concluded. MWI — This experiment is described in the Report on the Mid-Country Station. 1968 Experiments Wll — Levels of surfactant on the herbicidal activity of'diuron — Randomized block design with 3 replicates — (1968) Four levels of Surfactant N (supplied by the Shell Co. of Ceylon Ltd), viz 0, \, 1|, 2£ and 3£ pints in 50 gallons of spray volume per acre were tested at two levels of diuron (one lb and two lb ai per acre). The most common weeds observed in the experimental plots were Crassocephalus crepidioides, Digitaria pps., Drymaria cordata, Polygonum spp., Crepis javanica and Cyanotes villosa. 5 0 . 2 4 3 . 7 4 9 . 7 2 6 . 4 9 . 8 6 1 . 2 6 1 . 7 6 1 . 8 4 1 . 4 1 1 . 8 2 1 . 1 2 0 . 5 2 1 . 6 1 5 . 6 5 , 2 32 A N N U A L REPORT FOR 1968 Appreciable leaf scorch symptoms were observed only one week after spraying. Leaf scorch symptoms were assessed visually at weekly intervals up to the fifth week after spraying. No marked effect of the levels of surfactant was observed at either levels of diuron; the two lb level of diuron was slightly superior to the one lb level. W12 — Amitrole T and Gramoxone on Panicum repens — Randomized block design with 4 replicates — (1968) The following treatments were being compared : 1 — 2 lb per acre Amitrole T 2 — J lb per acre Amitrole T followed by i pint Gramoxone per acre two weeks later 3 — I pint Gramoxone per acre only. This experiment is laid out in an area with a uniform stand of Panicum repens (Couch). Amitrole T is a mixture of amino triazole and ammonium thiocyanate. Leaf and stem cholrosis were observed on the second day after spraying Amitrole T and these; symptoms continued down the stem changing its colour from yellowish white to light pink: Gramoxone alone scorched the leaves and stems severely, arid there was good weed control up to the fourth week. Rapid regeneration and new growth was observed thereafter. Amitrole and Gramoxone in combination gave good control up tct the sixth week and regrowth was noted thereafter but not to the same extent as in the plots treated only with Gramoxone. Amitrole T at two lb gave good control up to the seventh week, after which there was a very slow regeneration and a gradual disappearance of chlorotic symptoms. Control with any of the treatments tested, was in no instance complete. W13 — Gramoxone and diuron separately and in combination on weeds in VP tea areas — Randomized block design with 4 replicates — (1968) Two levels of Gramoxone (J and 1 pint per acre) and two levels of diuron (1 and 2 lb per acre) were tested separately and in combination, to test the efficacy of mixtures of herbicides for better weed control. The weed control was estimated visually at monthly intervals for four months after spraying and the1 summarized results are presented in Table 12. TABLE 12 — Effect of Gramoxone and diuron separately and in combination, on weed growth in VP tea areas T r e a t m e n t G r a m o x o n e Diuro i (pints) (lb) — 1 i — 1 — I 1 i : 2 l i 1. 2 1st m o n t h 2nd m o n t h 3rd m o n t h 4 th m o n t h + + _i—i—L + + + .+ + + + + + + + + + + + -f + + + + + + + + + + + + + + + + + + + + + + + +' + - f - r - r + • • ' + + + + + + + + + + + + . + T + + -!.. _!_ a. .i. + + -r- T + + 4 - Very good cont ro l -r G o o d control • + Very satisfactory control + Satisfactory control ANNUAL REPORT FOR 1968 33 The higher level of diuron was slightly more effective than the lower level with respect to weed control, but it was also noticed that in some instances, slight chlorotic symptoms appeared in tea plants at the higher level of diuron. There was no marked difference between the control obtained with the two levels of Gramoxone. When applied alone, Gramoxone gave poor control after the second month compared with diuron. All mixtures of Gramoxone and diuron had a marked residual effect and the combination of one lb diuron and half pint Gramoxone gave good control up to the fourth month. It was not possible to draw definite conclusions from these preliminary obser­ vations, because of the wide variation in weed growth observed initially between plots. W14 — Diuron, Simazine and Gramoxone on weeds in VP tea areas — 6 x 6 latin square — (1968) The plots used previously for Experiment Wl were pruned in July and a new set of treatments was assigned. The present experiment is designed to control weeds with two levels of diuron, two levels of Simazine and one level of Gramoxone and to determine the effect of these treatments on the yield of tea. The first applications of the treatments were given late in the year and the results are not yet available. W. B. Manipura & A Somaratne Extension Experiments Yield expressed as pounds dry weight per acre per annum and the period for which the yield has been summarized are quoted separately for each ex­ periment. Fertilizer levels are quoted as pounds per acre per annum for nitro­ gen (N) and for potash (K aO). In experiments comparing levels of Limbux only one application at the rates 0, 1 and 2 tons per acre has been given, at the beginning of each experiment. All results should be taken as indicative of trends observed, and no conclusion should be drawn at this stage. Experiments XA11 and XA12 have been abandoned! XA1 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels on seedling tea at Tangakelle Group, Lindula-^-* (1965) Table 13 shows the response to the three levels of nitrogen. TABLE 13 — Yield response for the period 21.9,67 to 30.11.68 Nitrogen treatments Yield (lb per acre per annum) (lb per acre per annum) 120 240 360 L S D (P = 0 . 0 5 ) There is a response to levels of nitrogen. The use of? different types of nitrogen did not give any significant differences in yield. XA2 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels on seedling tea at Mayfield Estate, Kotagala — (1965) 1866 2129 2314 283 34 ANNUAL REPORT FOR 1968 Table 14 shows the response to the levels and types of nitrogen. TABLE 14 — Yield response for the period 19.6.67 to 20.5.68 Type of nitrogen Yield treatments (lb per acre per annum) Sulphate o f ammonia 2523 Calcium ammonium nitrate 2245 Urea 2245 Levels of nitrogen (lb per acre per year) . 120 1867 240 2498 360 2647 L S D {P mt 0 . 0 5 ) 114 Yield differences are significant for levels of N as well as for types of N. XA3 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels on seedling tea at Hauteville Estate, Agrapatana — (1965) Yield data for the period 7.10.67 to 8.10.68 were statistically analysed but there were no significant differences in yield resulting from the use of different levels of nitrogen (120, 240 and 360 lb) or types of nitrogen. XA4 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash on seedling tea at Diyagama East, Agrapatana — (1965) Table 15 shows the yield response to the'three levels of nitrogen. TABLE 15 — Yield response for the period 4.6.66 to 3.7.68 Nitrogen treatments Yield Ob per acre per annum) (lb per acre per annum) 120 3105 240 3197 360 3357 L S D (P = 0 .05 ) 130 There is a significant response to levels of nitrogen, but the yield differences resulting from the use of different types of nitrogen and different levels of potash were not significant. XA5 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels on VP tea at Ederapolla Group, Bulathkohupitiya — (1965) Table 16 shows the yield response to the three types of nitrogen. TABLE 16 — Yield response for the period 14.12.66 to 23.7.68 Type of nitrogen Yield (lb per acre per annum) Sulphate of ammonia 3192 Calcium ammonium nitrate 3033 Urea" 3233 L S D CP =* 0 .05 ) 138 ANNUAL REPORT FOR 1968 35 Yield differences were significant for the three types of nitrogen but not for the levels of nitrogen. XA6 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash on seedling tea at Blairlo- mond Estate, Udapussellawa — (1965) Yield data were summarized for the period 14.11.67 to 14.11.68 and statistically analysed. None of the treatments gave significant yield differences at the 5% level of probability. XA7 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3_ levels in combination with 3 levels of Limbux on seedling tea at Kirkos- wald Group, Bogawantalawa — (1966) « Table 17 shows the yield response to the three levels of nitrogen. TABLE 17— Yield response for the period 17.8.66 to 13.7.68 Nitrogen treatments Yield (lb per acre per annum) (lb per acre per annum) 120 1921 240 2223 360 2439 L S D (J" = 0 . 0 5 ) 214 There is a significant response to the three levels of nitrogen but not to the other treatments. XA8 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash at Brunswick Group, Mas- keliya — (1966) Table 18 shows the yield response to the types and levels of nitrogen. TABLE 18— Yield response for the period 18.8.66 to 9.6.68 Type of nitrogen treatments Yield (lb per acre per annum) Sulphate of ammonia 2724 Calcium ammonium nitrate 2565 Urea 2503 Levels o f nitrogen (lb per acre per annum) 120 2161 240 2635 360 2996 L S D (P = 0 . 0 5 ) 105 Sulphate of ammonia gave a significantly greater response than either of the other two types of nitrogenous fertilizer. There was ho significant response to levels of potash. There was a highly significant linear response to levels of nitrogen. 36 ANNUAL REPORT FOR 1968 There is a significant linear response to the levels of nitrogen but not to other treatments. XA14 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 *" levels in combination with 3 levels of potash at Dickoya Estate, Dick- oya — (1966) . The yield responses to the levels of nitrogen are given in Table 20. TABLE. 2Q — Yield response for the period 8.10.67 to 17.10.68 Nitrogen treatments Yield (lb per acre per annum) (lb per acre per annum) 90 1320 180 1565 270 1724 L S D (P - 0 . 0 5 ) 70 The yield response to levels of nitrogen is significantly linear. There was no significant response to the types of nitrogen or to the different levels of po­ tash. XA15 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3. ... leveh in combination with 3. levels of potash at Kotiyagala Ejstate, Bogawanialawa — (1966) XA9 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux at Holyrood Estate, Tala- wakele — (1966) . Yield data were summarized for the period 17.8.67 to 17.8.68 (first year after pruning). None of the treatment effects reached significance at the 5 % level of probability. XA10 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash at Clarendon Estate, Nanu Oya — (1966) .Yield data were summarized for the period 28.5.67 to 5.6.68. Statistical analysis of the results was carried out and none of the treatments gave a signi­ ficant response. XA13 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash at Ottery Estate, Dick- oya — (1966) The yield response to the levels of nitrogen are given in Table 19. TABLE- 19— Yieldresponse for the period 23.12.66 to 6.7.68 Nitrogen treatments Yield Ob per acre: per annum) (lb per acre per annum) 9 0 2130 180 2242 270 2417 L S D ( > - 0 . 0 5 ) 134 ANNUAL REPORT FOR 1968 37 90 1856 180 1954 270 2100 L S D CP = 0 . 0 5 ) 65 There was a significant response to the different levels of nitrogen but not for the other treatments. XA17 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with three levels of Limbux at Diyagama East Estate, Agrapatana — (1966) The yield response to the different types and levels of nitrogen are given in Table 23. TABLE 23 — Yield response for the period3.4.67 to 23.5.68 Type of nitrogen treatments Yield Ob per acre per annum) Sulphate of ammonia 2458 Calcium ammonium nitrate 2615 Urea 2617 : Levels o f nitrogen Ob per acre per annum) 90 2334 180 2511 270 2844 L S D ( P = 0 .05 ) 131 There was a significant linear response to the different levels of nitrogen. Yield differences between types of nitrogen Were significant at the 5% level of probability. There was no significant response to the different levels of Limbux. The yield responses to the levels of nitrogen are given in Table 21. TABLE 21 — Yield response for the period 5.1.67 to 22.7.68 Nitrogen treatments Yield Ob per acre per annum) Ob per acre per annum) 90 1830 180 2048 270 2301 L S D CP = 0 . 0 5 ) 262 The response to levels of nitrogen is significantly linear. There was no significant response to the levels of potash and no significant yield differences resulted from the use of different types of nitrogen. XA16 :— Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux at Oonagaloya Estate, Kotmale — (1966) The yield responses to the levels of nitrogen are given in Table 22. TABLE 22 — Yieldresponse for the period 4.6.67 to 28.6.68 Nitrogen treatments Yield Ob per acre per annum) Ob per acre per annum) 38 ANNUAL REPORT FOR 1968 XA18 r 1 - Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux at Gonapitiya Estate, Kandapola •— (1966) The yield response to the different levels of nitrogen are shown in Table 24. TABLE 24 — Yield response for the period 2 7 . 5 . 6 7 to 29.6.68 Nitrogen treatments Yield (lb per acre per annum) (lb per acre per annum) 90 2701 180 2893 270 3059 L S D CP = 0 . 0 5 ) 248 There was a significant linear response to the different levels of nitrogen but no other treatment effects were significant. S. Sandanam, W. B. Manipura & C. C. Rajasingham Acknowledgements We wish to thank the Superintendents and other staff on estates where our experiments are located, for their kind co-operation and help. The assis­ tance of the Statistician and his Assistant in statistical designs and analyses is greatfully acknowledged. Our thanks are also due to Dr R. L. Wickrema- singhe for the use of the Biochemistry laboratory facilities; to Dr U. Pethiyagoda and Mr S. Krishnapillai for their co-operation and help in sand culture work and to Drs P. B. Vose and H. Broeshart of the IAEA Research Laboratories in Vienna for the N 1 5 analysis. Visits, Lectures and Symposia Lecture Dr V. P. Bhavanandan addressed the members of the Chemical Society of Ceylon, on the subject "The Chemistry of the mucopolyscaharides" in June. Symposium Dr V. P. Bhavanandan and Dr W. B. Manipura participated in a sympo­ sium on 'Drought' held at Badulla for the Uva Planters' Association. Publications BHAVANANDAN, V. P. & MEYER, K. (1968). Studies on Keratosulfates. J. Biol: Chem. 2 4 3 , 1052-1059. References CHIRANJEEVI, RAO, K., KRISHNAMURTHY, T . N. & THULJARAM RAO, J. (1967). Cation-Exchange capacity of roots and yield potential of sugar cane. Plant and soil, 2 7 , 314-318. SHANMUGANATHAN, N. & FERNANDO, S. R . A. (1967). Some observations on Poria control by soil fumigation with methyl bromide. Tea Q. 38, 311-319. WICKREMESINGHE, R . L., PERERA, B. P . M. & D E SILVA, U. L. L. studies pn the quality and flavour of tea—4—Observations on the biosyn­ thesis of volatile compounds, (1969). Tea Q. 4 0 , 26-30. REPORT OF THE PLANT PHYSIOLOGY DIVISION Research Officer — S. Kulasegaram, BSc, PhD, MIBiol General The year under review was marked by the absence of four members of the Division including Dr U. Pethiyagoda, the Plant Physiologist, who left for the UK in March for one year on a post-doctoral fellowship, awarded by the Nuffield Foundation. Dr S. Kulasegaram was in charge of the functioning of the Division during the absence of the Plant Physiologist. Messrs A. R. Sebastiampillai, S. Kandiah and S. Nagarajah continued their post-graduate studies abroad. Mr A. Nanayakkara resigned from his post of technical assis­ tant in August. Laboratory Investigations Growth of tea in sand culture Induced nutrient deficiencies Nutrient deficiency symptoms for nitrogen, potassium, calcium, magne­ sium and sulphur were induced in clone CY9. A description of the foliar deficiency symptoms in respect of the above elements was given in the Annual Report for 1967. In view of the apparently unusual response of clone CY 9 to magnesium deficiency, four clones, TRI 2024, TRI 2027, DT 1 and TC 9, were grown in sand culture using nutrient solution lacking in each of the fiye major nutrients mentioned above, to test the possibility of clones differing in their expression of nutrient deficiency symptoms. All clones under investigation behaved in a manner similar to clone CY 9. Magnesium deficiency induced a faint interveinal chlorosis, the affected leaves being shed shortly afterwards. Clone TRI 2024 was exceptional in its reaction to potassium deficiency. The plants showed progressive yellowing of the leaves along the margins before the characteristic foliar scorch symptoms of potassium deficiency developed. Foliar deficiency symptoms were successfully corrected by introducing the deficient element concerned in the nutrient solution. Plants under the corrective treatments showed no further progression of the symptoms in the affected parts and produced normal new leaves. Interaction between aluminium and certain other minor elements Three experiments designed to study the interaction between aluminium and iron, manganese and fluorine respectively on the growth of clone TRI 2025 have been described in the Annual Report for 1967. All plants in the three experiments were pruned in March 1968 at a height of one ft arid the tops weighed. No significant differences in top weights were noted in respect of the levels of aluminium, iron or fluorine. No differences were evident in the ap­ pearance and growth of the plants treated with these elements. There was a significant reduction in top weights in the treatments receiving no manganese. This was evidently due to severe deformity, scorch and premature shedding of leaves, symptoms characteristic of manganese deficiency. The plants re­ covered well from the pmne but have since declined in growth. An interesting observation was that even the plants that were grown without manganese recovered well butdeve^ped foliar symptoms of deficiency quite soon. 39 40 ANNUAL REPORT FOR 1968 The levels of supply of iron, fluorine and manganese have since been in­ creased tenfold ie to 0, 10, 20 and 40 ppm. Plants receiving high levels of fluorine as sodium fluoride showed severe scorch of foliage and most of the plants have progressively died. Further experiments are planned to test whe­ ther the toxicity resulted from the high levels of sodium (introduced from other salts as well) or from the fluorine. Effect of aluminum on growth Two experiments were initiated to study the effect of different levels o f aluminium on the growth of young seedlings from open-pollinated seeds o f clone TRI 2024. In one experiment, aluminium (as aluminium sulphate) was supplied twice a week to these plants at 0,2, 4 and 8 ppm. On other days o f the week the plants were given Hewitt's solution at half strength. In the other experiment aluminium at 0, 10, 20 and 40 ppm was included in the nutrient solution and given daily to these plants. The experiments are in progress. Comparison between nitrate and ammonium as forms of nitrogen for tea plants The experiment was to determine the optimum manner of supplying nitrogen to tea plants in sand culture—whether as nitrate or ammonium or as a mixture of the two forms. Young plants of clone DT 1 were supplied the different nutrient solutions after an initial stabilising period of two months. Each plant received a constant volume' of nutrient solution containing an equivalent of 100 ppm of nitrogen. Between the extreme treatments which consisted of nitrate or ammonium as the only source of supply of nitrogen, were nine mixtures of'ammonium and nitrate, separated by steps of ten ppm. As the. nitrate nitrogen content rose by ten ppm, the ammonium dropped by an equal amount so that the total nitrogen level remained at 100 ppm. The eleven treatments were replicated five times. Plants receiving nitrogen mainly or only as ammonium produced darker green leaves than those receiving a greater proportion of their nitrogen as nitrate. The former, however, subsequently developed a characteristic chloro­ sis of their leaves which were also crinkled and recurved along the stem axis. These plants were also much smaller in size, the best growth apparently being shown by plants in the median treatment region. Plants receiving large pro­ portions of nitrate also showed a characteristic scorching of leaves. Growth assessments and analyses are due to be carried out shortly. S. Krishnapillai Field Experiments and Trials The following experiments have been concluded : PHI, PH4, PH6, PH9, PH19, PH21, PH22, PH23, PH27 and XPH8. PH3 — Growth Analysis — (1963) Two further assessments were recorded during the year. While statistical analysis awaits the completion of further assessments, the following general trends have emerged : 1 — Bending, cut-across pruning and plucking have all reduced plant weight relative to the untouched free-growing treatment. This is also generally true for the weights of the component plant parts— stem, leaf and root. ANNUAL REPORT FOR 1968 41" 2 — There are indications that with the passage of time, the initial setback to growth is gradually overcome and the gap narrow. The greatest initial reduction arose from the formative cut-across prune. Bending and plucking have exerted relatively mild effects. 3 — While in the first four years the free-growing treatment was the \ superior one, it is likely that as maximum plant size is approached, the bushes in plucking may overtake them in dry matter production. There is a suggestion that this reversal has occurred or is imminent in clone TRI 777 whose final size is smaller than the other clone in the experiment, TRI 2142. The tea is to be pruned shortly. PH5 — Mulching — (1965) The experiment has now progressed for a further period since commence­ ment and the analysis of the yields recorded during the period under review is presented in Table 1. TABLE 1 — Effects of different types of mulch and levels of nitrogen on yield—Mulch applied monthly to pro* vide 6.2 tons fresh matter per acre per annum- Nitrogen at four-monthly doses to provide 45, 135 and 225 lb per acre per annum Mulch treatments Yield (lb fresh weight per plot for 151 plucks from 3 1 . 1 2 . 6 5 to 3 1 . 1 2 . 6 8 ) All leaf swept away 214 .90 Mana 2 3 5 . 9 9 Grevillea robusta 262 .27 Tea 272 .99 Dadap 2 7 6 . 4 0 L S D (P = 0 .05 ) 16 .84 .. . CP = 0 . 0 1 ) .. 2 2 . 8 2 .'• ( > = 0 . 0 0 1 ) 3 0 . 5 6 Mean yield for all mulched treatments 262 .41 Yield for swept control 2 1 4 . 9 0 L S D (P = 0 .001) 41 .31 Nitrogen treatments Yield (lb N per acre per annum) (lb fresh weight per plot for 151 p lucksfrom 3 1 . 1 2 . 6 5 to 3 1 . 1 2 , 6 8 ) 45 2 1 8 . 2 0 135 250 ,57 225 289 .95 L S D {P = 0 .001) 23 .67 As reported previously, nitrogen as well as the mulch treatments have had significant promotive effects on yield. There was no significant interaction between mulch treatments and levels of nitrogen. The beneficial effects of the additions of the different types of mulch followed the same pattern as reported earlier. The three other types of mulch were all superior to Mana and did not differ significantly among themselves. The yields obtained for 57 plucking rounds from the supplementary plots in the experiment involving the additions of tea leaf droppings confirm the beneficial effects of tea leaves as. mulch. H. B. Wije tunga & S. W i m a l a d h a r m a 42 ANNUAL REPORT FOR 1968 Treatment Length of plucking N o . of Yield Yield Calculated round (days) plucking (lb green leaf per pluck made tea per rounds per plot) (lb) acre per annum 0 b ) 7 (fish leaf) 52 4 0 5 . 3 7 . 7 9 1277 . 3 121 3 9 2 . 5 3 . 2 4 1236 5 • i 73 . 3 8 8 . 6 5 . 3 2 1224 Alternating 4 & 10 52 3 7 7 . 4 7 . 2 6 1189 9 40 3 6 9 . 9 9 . 2 5 1165 7 (single leaf) 52 3 6 3 . 0 6 . 9 8 1143 Alternating 6 & 8 52 323 .1 6 .21 1018 10 36 3 1 3 . 2 8 . 7 0 987 14 26 2 9 0 . 4 11 .17 915 L S D for total yields P = 0 . 0 5 2 9 . 8 P = 0 .01 3 9 . 9 P = 0 .001 5 2 . 4 Of the frequencies involving normal plucking there was no significant difference between three, five, alternating four and ten, nine and seven-day rounds. These proved to be significantly superior to the rest. Fish leaf plucking on a seven-day round gave the highest yields and was significantly different from the longer plucking rounds of nine, seven, alternating six and eight, ten and 14 but not significantly different from the shorter rounds of three, five, and alternating four and ten. This experiment has been concluded. H . B. Wije tunge & S. W i m a l a d h a r m a PH12 — Hakea saligna as a shelter-belt plant — (1965) The experiment continues. PH13 — Rested tea bushes as shelter belts — (1965) The absence of a consistent relationship between plot positions, relative t o the rested rows, may arise from their unsatisfactory alignment with respect t o wind direction. This trial is to be concluded shortly. PH14 — Total available carbohydrate (TAC) levels and recovery from pruning — (1965) PH15 — Quantities of total available carbohydrates (TAC) and recovery from pruning — (1965) No further studies were undertaken on experiments PH14 and PH15 during the year. PH20 — Plucking frequencies and yield — (1967) The mean yield obtained since commencement of the experiment are given in Table 3, TABLE 2 — Mean yield obtained from different plucking frequencies and combinations, on seedling tea— Yields of green leaf per plot are for 12 months of plucking—Figures for made tea per acre per annum are approximate figures based on an assessed bush density of"300 per acre and an out­ turn of'21% made tea ANNUAL REPORT FOR 1968 43 P H 2 4 — Gibberellic acid applications on young nursery plants — (1967) Gibberellic acid as a 200 ppm aqueous solution was applied as a drenching spray to six and ten-week old cuttings of TRI 2025 and TC 9. The two clones were chosen for their contrasting vigour in the nursery. The times of applica­ tion were selected to roughly coincide with stages of root initiation and active growth respectively. Batches of ten treated plants are to be sampled at six, 13, 20 and 27 weeks from planting, along with unsprayed controls. D . Janakiram P H 2 5 — Growth retardants on tea — (1967) No further studies on this subject were undertaken. P H 2 6 — Studies on banji — (1967) Studies on this subject were continued and the observations made and results obtained have been given in a paper "Studies on the dormancy of tea shoots : 1. Hormonal stimulation of the growth of dormant buds" which has been submitted for publication in The Tea Quarterly. Preliminary grafting experiments showed that the technique of reciprocal grafting of active and dormant shoots on young plants in one state or another of growth in relation to the conditions of the terminal buds may be used in studying the source and nature of the factor governing dormancy or growth. Although it takes a minimum period of about eight weeks in a mist chamber, for the graft union to become effective, by which time the dormant bud in the ungrafted plant may have become active, it is felt that by using grafted controls it would be possible to overcome this difficulty. A start has also been made in the experimental control of growth or dormancy by using the split-root technique. It is also hoped to study the levels of other important endogenous growth regulators and inhibitors in dormant buds, in buds resuming growth and in active buds, which may help in understanding the nature of dormancy in tea. P H 2 8 — Pruning of clonal tea at Welimada Group, Welimada — (1967) Visual observations made on recovery did not appear to have shown differences between any of the treatments tested. H. B. Wijetunge & S. Wimaladharma P H 2 9 — Growth factors and recovery from pruning in clone TRI 2025 — (1967) In a preliminary experiment on the above subject, some growth factors such as sucrose, gibberellic acid (GA3), indoIylT3-acetic acid (IAA), all at 800 ppm and kinetin at 50 ppm and some combinations of these were applied on to the pruned frames three times on alternate days. 44 ANNUAL REPORT FOR 1968 All treatments applied increased the total number of buds developing and the number of buds developing per unit area of the pruned frame compared with the control in the following decreasing order of efficacy at the concentra­ tions employed: kinetin (K) -f gibberellic acid (GA,), indolyl-3-acetic acid (IAA) + GA 3, K, IAA, GA 3 , and sucrose. Although the total length of shoots was increased by GA 3 , sucrose and K + GA 3 , only in GA S treated plants was the mean length of shoots greater than that of the control. IAA followed by GA 3 produced a greater number of measurable shoots ( > 0.5 cm) at eight weeks from pruning. It appears that by the appropriate choice of growth factors at the correct concentrations better recovery and frame development may be obtained. It is hoped to follow this line of work. CLONAL TESTING No additional clones were selected and/or tested apart from the testing of the ; performance of the already selected clones which are in the clonal testing experiments at the different locations. The ranking of the clones in the respec­ tive experiments has been made on the basis of total yields obtained over the periods indicated for each experiment. No direct comparison of the yields obtained at the different locations can be made as the experiments have pro­ gressed through different stages in the cycle and the completed cycle yields are not available for comparison. Information on the length of time covered from prune and the length of time each experiment has been in plucking is also given in the Tables 3 to 8 along with the calculated mean yields as made tea per acre, obtained to-date for the different clonal trials. The clones in each table have been arbitrarily grouped into three yield categories similar to that presented in the report for 1967, ie over 2500 lb, between 2500 and 1500 and below 1500 lb made tea per acre per annum. It will be noted that fewer clones have been included in the higher yield catego­ ries in the second cycle compared with that of the previous year. This is because of a variation in the method of computation of the yields obtained into made tea per acre per annum. Earlier, the yields were calculated for 52 Weekly plucks which covered a year. It was felt that while this may be satis­ factory for the calculation of the first cycle yields it would not give a realistic estimate of yield in relation to time for subsequent cycles as it does not take into account the non-productive period of recovery following pruning and, therefore, gave disproportionately high yields. The yield classification of clones has now been made on yield calculated for a period of 12 months follow­ ing pruning, and not for 12 months following first pluck after pruning. VP1 — Clonal testing at St Coombs — (1961) MVP1 — Clonal testing at the Mid-Country Station — (1961) UVP1 — Clonal testing at the Uva Station — (1961) LVP1 — Clonal testing at the Kottawa Substation — (1961) VP1, MVP1 and UVP1 are at various stages in the second cycle, while LVPl is in the third cycle but has not completed a year from pruning, and has, therefore, been omitted from Table 3. A N N U A L REPORT FOR 1968 45 TABLE 3 — Rank of clones on the basis of yields obtained for the periods indicated in experiments VPl, MVP1 and UVP1 — Clones shown in heavy type gave a mean calculated yield per acre per annum of more than 2500 lb — Clones shown in plain type gave a mean calculated yield per acre per annum of between 1500 and 2500 lb — Clones shown in italics gave a mean calculated yield per acre per annum of less than 1500 lb SECOND CYCLE N o . of months from prune N o . of months in plucking- Calculated mean yield (made tea per acre) for the period indicated Yields as made tea per acre per annum V P l M V P 1 U V P 1 KEN 16/3 TRI 2023 T R I 2023 TRI 2025 TRI 2026 T R I 2027 M T / B G TRI 2025 T R I 2025 C Y 9 K E N 16/3 T 5 / 3 T R I 2027 D G 3 9 T R I 2026 N TRI 2151 K E N 16/3 T R I 2023 N U H 9 / 3 TK48 M T / B G N T R I 2024 G M T 9 G M T 9 D T I M T 18 B G 18 T R I 2026 T R I 2027 C Y 9 G M T 9 T 5 / 3 N L 4 / 2 Seed T 5 / 3 5 D T I CV 5/B1 TRI 2024 D G 3 9 K 1 5 0 P A 22 T K 4 8 TRI 777 . E N 31 MT/BG U H 9 / 3 N L 3/1 CV 4/B1 K 1 3 6 ••: D T 1 T R I 2151 P A 22 T K 4 8 E N 31 M T 1 8 , K 1 3 6 CV 5/B1 T 5 / 3 C Y 9 K 1 5 0 PO 2 6 . , Q T 1 / 5 Q T 1 / 5 D G 39 P 0 26 TRI 2024 NL 3 / 1 . N L 4 / 2 PO 26 KEN\S'ir- T R I 777 T 5 / 3 5 TJW2151 KEN 15/7 PA 22 CRA K150 AT 136 7" 5/35 Seed TRI 777 S r i / 5 CV5/BI /VX3/1 £AT31 CRA KEN 15/7 CVA\B\ UH9P Seed /vX'4/2 '"• CVA\B\ CRA 2 2 " " 24 36 12 19 28 1845 ± 1 0 4 4066 ± 2 2 5 4830 ± 1 3 7 1845 2568 2070 VP2 — Clonal testing at St Coombs—{1962) MVP2 — Clonal testing at the Mid-Country Station—(1962) UVP2 — Clonal testing at the Uva Station—{1962) LVP2 — Clonal testing at the Kottawa Substation—{1962) VP2, MVP2, UVP2 and. LVP2 are all in their second cycle. The clones in VP2 have not been ranked in Table 4 because they have still not com­ pleted a year from pruning. 46 A N N U A L REPORT FOR 1968 T A B L E 4 — Rank of clones on the basis of yields obtained for the periods indicated in experiments MVP2, UVP2 and LVP2 = Clones shown in heavy type gave a mean calculated yield per acre per annum of more than 2500 lb—Clones shown in plain type gave a mean calculated yield per acre per annum of between 1500 and 2500 lb—Clones shown in italics gave a mean calculated yield per acre per annum of less than 1500 lb 2nd CYCLE N o . of months from pruning N o . of months in plucking Calculated mean yield (made tea per acre) for the period indicated Yield as made tea per acre per a n n u m M V P 2 U V P 2 LVP2 K P 2 0 4 K P 2 0 4 TRI 2022 TRI 2016 M G TRI 2024 C H 13 TRI 2024 K P 204 TRI 2022 TRI 2039 TRI 2043 N K 4/B29 TRI 2016 M P A 1 M P A 1 rJU2022 NK 4/B29 TRI 2039 H13/4 TRI 2039 T R I 2043 NK4/B29 N A Y 3 N A Y 3 CH 13 M G M G 3 / B 1 NAY 3 TRI 2016 D TRI 7043 C H 1 3 M G MG 3/Bl M G 3 /B l T R I 2024 MPA 1 H 1 3 / 4 T R I 2020 D TRI 2020 O T 5 / 8 TRI 2020 D H 6 A l H6A\ H 6 A l 12 26 30 8 19 26 733 ± 5 0 2909±114 9256±763 1837 4272 VP3 — Clonal testing at St Coombs—(1963) MVP3 — Clonal testing at the Mid-Country Station—(1963) UVP3 — Clonal testing at the Uva Station—{1963) L V P 3 A N N U A L REPORT FOR 1968 Clonal testing at the Kottawa Substation—(1963) 4 7 VP3 and MVP3 have completed 36 months of plucking in the first cycle while UVP3 has completed 19 months of plucking in the first cycle LVP3 has completed the first cycle and is now 18 months from pruning in the second cycle • -i< TABJJE 5 — Rank of clones on the basis of yields obtained for the periods indicated in experiments VP3, MVP3, UVP3 and LVP3—Clones shown in heavy type gave a mean calculated yield per acre per annum of more than 2500 lb—Clones shown in plain type gave a mean calculated yield per acre per annum of between 1500 and 2500 lb—Clones shown in italics gave a mean calcula­ ted yield per acre per annum of less than 1500 lb 1ST C Y C L E 2 N D C Y C L E V P 3 M V P 3 U V P 3 LVI»3 B 2 7 5 T R I 2 0 2 1 B 2 7 5 TRI 2045 T G K 2 D G 7 T R I 2021 TRI 2021 W / 2 - 1 4 5 T R I 2024 T R I 2024 D G 3 D G W3 DG3 D G 7 El/27 DG 3 DG7 TRI 2024 W3 >f/2-145 TRI 2046 B 2 7 5 T R I 2 0 4 6 £ 7 / 2 7 £ 7 / 2 7 E 7 / 2 7 T R I 2 0 2 1 TRI 2046 H72-145 W/2-145 D G 3 DG DG 43 D G 4 3 D G 7 TGK2 TGK2 D G ML 7 77?/2045 W3 TRI 2046 TRI2024 ML 7 DG T G K 2 TRI 2045 W 3 ML 7 M L 7 N o . o f months from prune N o . o f months in plucking 36 Calculated mean yield (made tea per acre) for the period indicated 6089 ± 4 6 3 Yields as made tea per acre per annum 2030 36 1 1 5 8 ± 3 6 386 19 1300 18 15 2058 ± 9 4 5718 ± 3 4 2 • 4574 VP4 — Clonal testing at St Coombs—{1964) MVP4 — Clonal testing at the Mid?Country Station-r-(1964) 48 A N N U A L REPORT FOR 1968 U V P 4 — Clonal testing at the Uva Station—(1964) LVP4 — Clonal testing at the Kottawa Substation—(1964) TABLE 6 — Rank of clones on the basis of yields obtained for the periods indicated in experiments VP4, MVP4, UVP4 and LVP4—Clones shown in heavy type gave a mean calculated yield per acre per annum of more than 2500 lb—Clones shown in plain type gave a mean calculated yield per acre per annum of between 1500 and 2500 lb—Clones shown in italics gave a mean calcu­ lated yield per acre per annum of less than 1500 ft 1ST C Y C L E VP4 M V P 4 U V P 4 L V P 4 M O 241 P G G 2 P L L G 2 CW12 D W 12 M O 116 TRI 1114 H l / 5 8 Q T 4/4 D W 12 D W 12 TRI 2024 M O 146 L A N S . S E E D T R I 2024 TRI 1526 M O 208 T R I 2024 Q T 4 / 4 TRI 1530 TRI 1114 H l / 5 8 M O 116 L A N S . S E E D T R I 2142 T R I 1114 : M O 208 D W 12 P L L G 2 Q T 4/4 CW 21 Q T 4 / 4 M O 116 P L L G 2 C A R 7/10 ILLUK. S E E D MO 114 I L L U K . S E E D T R I 2142 P L L G 2 TRI 1530 M O 208 L A N S . S E E D CAR 7/10 TRI 1526 M O 241 I L L U K . S E E D M O 146 LANS. SEED C A R 7/10 -•• M O 116 CAR 7/10 M O 146 T R I 1114 77W2024 T R I 1530 M O 208 ILLUK: SEED M O 114 M O 114 24 24 18 24 3 0 5 4 ± 2 1 1 ' 1 7 1 9 ± 5 4 • 1 8 6 0 ± 4 4 5743 + 419 1527 8 6 0 - 1240 2872 N o . of months from prune N o . of months in plucking Calculated mean yield (made tea per acre) for the . period indicated' ' Yield as made tea per acre per 'annum V P 5 — Clonal testing at St Coombs—{1965) MVP5 — Clonal testing at the Mid-Country Station—(1965) LVP5 — Clonal testing at the Kottawa Substation—-(1965) ANNUAL REPORT FOR 1968 .49 TABLE 7 — Rank of clones on the basis of yields obtained for the periods indicated in experiments VPS, MVP5 and LVP5—Clones shown in heavy type gave a mean calculated yield per acre per annum of more than 2500 lb—Clones shown in plain type gave a mean calculated yield per acre per annum of between 1500 and 2500 lb—Clones shown in italics gave a mean calculated yield per acre per annum of less than 1500 lb 1ST C Y C L E V P S M V 4 L V P 5 T C 9 T R I - 2 0 2 4 T R I 2 0 2 4 D K 1 L D 9 9 9 T R I 2 5 D K 8 D K 1 7 P K 4 T R I 2 0 2 4 D A 1 4 0 8 S 1 0 6 D A 1 4 0 8 C C 3 4 L D 9 9 9 K 1 4 5 K 1 4 5 D K 1 7 DIV21 D T 9 5 CC 3 4 Q T 3 / 3 T R I 2 0 4 5 1 2 6 2 4 8 5 3 ± 9 3 2 3 1 ± 2 0 2 0 5 4 ± 8 1 8 5 3 •— • 1 0 2 7 N o . of months from prune N o . o f months in plucking Calculated mean yield (made tea per acre) for the period indicated Yield as made tea per acre per annum LVP10 — Clonal testing at the Kottawa Substation—-(1965) TABLE 8 —Monk of clones on the basis of yields obtained for the periods indicated in experiment LVP10— Clones shown in heavy type gave a mean calculated yield per acre per annum of more than 2500 lb^- Clones shown in plain type gave a mean calculated yield per acre per annum of between 1500 and 2500 lb—Clones shown in italics gave a mean calculated yield per acre per annum of less than 1500 lb 1 S T CYCXE L V P 1 0 T R I 2 0 2 3 T 6 2 / 1 T 6 2 / 5 T 6 2 / 7 T 6 2 / 9 N o . o f months from prune — N o . o f months in plucking 2 4 Calculated mean yield (made tea per acre) fpr the period indicated 9 5 9 3 ± 7 4 5 Yield as made tea per acre per annum 4 7 9 7 VP17 — Clonal testing—{1966) This experiment was brought into plucking on 29.4.68 and is still in the first year of plucking but yields obtained so far indicate that clones SM 404, C 34, YF 6/1, PK 2 and TRI 62/9 are doing well. MVP6 — Clonal testing at the Mid-Country Station—{1966) This experiment was brought into plucking in November 1968. VP21 — Clonal testing—{1967) The plants were given a light cut-across in September 1968, tipped and brought into plucking in February 1969. MVP7 — Clonal testing at the Mid-Country Station^(l96T) This experiment has completed one year's growth.' 50 ANNUAL REPORT FOR 1968 No definite conclusions can as yet be made from these experiments on the value of shade, in general for clonal tea. This appears to be a problem which may be usefully studied at a more fundamental level. Close examina­ tion of the Tables 3 to 8 indicate that there is a general similarity in the ranking of the clones as reported previously although certain clones have shifted posi­ tions. These confirm the suggestion that clones may have regional climatic preferences. H . R. S o l o m o n , H . B . Ratnayake, A . M . Abeysinghe, N . L. C. Fernando, K. H . G. Gunapala & H. D . Jayasinghe Height of plucking table and yield Obervation made in VP1 on the growth of shoots and the increase in the height of the plucking table following pruning and tipping done uniformly on all clones indicated that there was a correlation between the rate of develop­ ment of the plucking table and yields, provided the clones are plucked on their respective merits and no attempt is made to maintain a level table over the entire clonal area. An estimate of this relationship was obtained by calcula­ ting the correlation coefficient between the mean heights of the plucking table and the yields recorded over this period (84 plucks) following pruning. A high correlation (r = +0.76) was obtained which was highly significant {P at 0.001 = 0.55). Table 9 gives the mean heights of the plucking table in inches along with the respective yields obtained over this period as lb made tea per acre. TABLE 9 — Mean height of clones in VP1 arranged in ascending order and their respective yields as lb made tea per acre over the same period (3.6.67 to 3.2.69) Clones C V 4 B 1 N L 4 / 2 T R I 2151 N L 3 / 1 T R I 777 T 5 / 3 5 K 1 3 6 Q T 1 / 5 U H 9 / 3 P 0 26 C R 4 T 5 / 3 M T 18 K 1 5 0 N G M T 9 T R I 2026 D G 3 9 P A 22 E N 31 T R I 2027 K E N 16/3 C V 5 B 1 K E N 15/7 M T / B G Seedling T K 4 8 T R I 2024 D T l T R I 2023 T R I 2025 C Y 9 it M e a n height Total yield (in.) 0b made tea per acre) 2 8 . 8 6 1241 3 0 . 0 2 1081 3 1 . 2 2 1791 3 1 . 5 2 2856 3 1 . 7 7 3873 3 2 . 1 7 2030 3 3 . 5 2 3803 3 3 . 6 8 2035 3 4 . 0 4 3624 3 4 . 2 5 3202 3 4 . 2 9 2143 34 .41 3172 3 4 . 4 5 3650 3 4 . 4 5 4056 3 4 . 4 5 4477 3 4 . 4 9 3888 3 4 . 6 7 4043 3 4 . 9 8 3321 3 5 . 2 2 3437 3 5 . 3 0 1606 3 5 . 4 3 4645 3 5 . 5 1 4958 3 6 . 0 0 4376 3 6 . 0 8 2953 3 6 . 1 4 4810 3 6 . 5 9 4060 3 6 . 6 5 4720 3 6 . 6 9 : 4449 3 6 . 9 9 4551 3 6 . 9 9 4738 3 7 . 2 6 5048 3 7 . 5 6 4709 Correlation coefficient r - 0 . 76*** CPaJ 0 .001 = 0 . 5 5 ) ANNUAL REPORT FOR 1968 51 In view of the high correlation obtained, regular height measurements of the plucking table along with their respective yields are being recorded in VP2 and MVP3 which have recently been pruned, to determine how long it takes before a significant correlation will be recorded. VP18 — Nursery growth characters and yield—(1967) . In this trial 15 clones differing in their yields were selected from VP1 and attempts were made to correlate several plant characters in the nursery at three stages (5 | , 8 £ and 12 months) from planting with their respective yields. Table 10 gives the correlation coefficients obtained, for some plant characters with mean first cycle yields. TABLE 10 — Some plant characters and their correlation coefficients with yield Plant character Correlation coefficients Stage of growth (months) 8J 1 2 Mean height 0 . 4 0 7 0 . 5 4 7 * 0 . 5 2 5 * Mean appendage number 0 . 4 8 0 0 . 4 1 8 0 . 3 5 S Mean leaf area 0 . 3 3 6 0 . 5 8 7 * 0 . 4 9 9 Mean total dry weight 0 . 5 8 5 * 0 . 5 9 7 * 0 . 6 6 1 * Mean top dry weight ,0.445 0 . 5 7 8 * 0 . 6 6 1 * Mean root dry weight 0 . 6 7 1 * 0 . 5 7 2 * 0 . 6 0 0 * L S D (J» = 0 .05 ) * significant at 5 % level It will be noted from the above that vigour of the plant in the nursery, as indicated by some of the characters listed above, at 8^ and 12 months would appear to give a better indication of their subsequent performance in the field than vigour determined at an earlier period in the nursery. If this relationship can be shown to hold true for a larger number of clones, it may help in the testing of clones subsequent to their selection, by reducing the period required to assess the performance of a clone so that at least the poorer clones can be discarded at the nursery stage. It is hoped to pursue this work. A. Nanayakkara VP19 —Flush characteristics of clones—(1967) Preliminary studies are in progress on the analysis of the components of the flush in the different clones in VP1, VP2 and VP3. Analysis in VP2 was interrupted as pruning became due. It is hoped to resume once the bushes are brought into plucking. D . Janakiram VP20 — Reaction of clones to drought:—{\9(n) • This experiment was carried out but there did not appear to be a correla­ tion between the degree of drought tolerance and the soil moisture levels associated with temporary and permanent wilting points, the percentage moisture in the tissues at each of these stages and speed of recovery on resump­ tion of watering, respectively. Wide differences were observed in plants within the clones. It was observed that within any one clone, plants which were growing actively wilted earlier than plants which were in the dormant state, on suspension of watering. To avoid any such differences it appears 'that a larger number of plants will have to be raised and carefully selected ac­ cording to their condition of growth to obtain meaningful results. It was also 52 ANNUAL REPORT FOR 1968 noted that larger pots than the ones used in the experiment should be employed so that there is sufficient soil for a reliable sampling to be carried out without damaging the roots of the plants. This would also permit gradual moisture depletion in the soil by the plants and may augment clonal differences. With the use of small pots soil moisture depletion was rapid so that clonal differences were not noticeable. In view of the above considerations it appears that repetition may give useful results. H. B. Wijetunge VP22 — Panasand and Panacide for the control of mosses—Randomized block design with type of chemical and time of application split on clones—2 replicates—(1968) Two commercial formulations Panasand and Panacide which were claimed to control algae and moss development on soil in nurseries were used. Pana­ sand was used at the rate of one part in 150 parts in the top quarter inch of the soil in the polythene sleeve and the Panacide was watered on the soil at the rate of 20 ml Panacide 40% solution in 100 gallons of water. Each of the chemicals was also used at half the above strengths. The treatments also included two times of application, one immediately after planting and the other after about four months. The clones used were DT 1 and TRI2025. Observations made on moss growth showed that both chemicals at the strengths used were effective in controlling moss growth for a period of about six months. Statistical analysis carried out on the effect of the chemicals on the growth of the plants after seven months from planting did not show any effect except for a slight decrease in root growth with Panasand when compared with the control. No significant difference in growth was observed for the two times of application. D . Janakiram VP23 — The influence of nodal position of a cutting on its rooting—4 replicates of 10 treatments in randomized blocks—(1968) In taking single-node cuttings for propagation, it is customary to discard the more tender and the more mature portions of the shoot. In a vigorous and succulent clone, this practice still furnishes a reasonable number of cut­ tings per shoot. In less vigorous clones, whose shoots mature into the redwood stage at a smaller distance behind the apex, acceptable cuttings are limited in number. This experiment re-examines the relationship between the maturity of a cutting (as indicated by its nodal position) and its rooting. The three clones selected, TRI 2025, TRI 777 and DT 1 vary in the succulence and vigour of their shoots. Ten consecutive nodal cuttings (after the top two leaves and the bud were discarded) were propagated from each shoot. The lower nodes in the slower-growing clones extended deep into the redwood portion of the shoot. The experiment is in progress. D . Janakiram PLANT BREEDING VP10 — Selections from open-pollinated clonal seedlings—(1962) The plants have just been brought into plucking and observations are being made so that the better performers can be propagated for testing on a larger scale. ANNUAL REPORT FOR 1968 53 VP11 — Selections from hand-pollinated seedlings—(1963) The plants are in a similar stage as those of VPlft, Yield records are being maintained. VP12 — Selections from bi-clonal progeny—(1964) Plucking continued and the yields recorded are presented below in Table 11. TABLE 11 — Mean yields as lb made tea per acre over 52 plucks (21.1.68 to 13.1.69) Population Yield T R I 2023 22^7 T R I 2024 2260 T R I 2026 2227 Lansdowne Seed 1354 ( M : T R I 2026 x F : T R I 2023) Rambukkande Seed 1324 ( M : T R I 2023 x F : T R I 2026) Lansdowne Seed lfl* ( M : T R I 2023 x F : T R I 2026) T R I 2024 (open pollinated) 935 L S D P = 0 . 0 5 373 0 . 0 1 505 0 .001 676 It will be clear from the above that the parent clones have continued to perform better than any of the seedling populations. The seedling populations show high variability and it appears that further selections should be made from these in order to estimate the maximum potential of the cross, VP13 — Seedling progeny from eight commercial seed gardens—(1965) No yield records have been maintained previously. It was decided that some estimate of yields may be important and records are now being kept. VP14 — Hand-pollinated seedlings—{1965) Observations are being continued VP15 — Field selections at No. 11 and No. 14 Fields, St Coombs—{1964) Yield records are being maintained Irradiation studies The exposure of living cells to certain types of radiations can induce changes in the genetic material which in turn cause changes in the expression of various plant characters. Such changes are called mutations and are generally per­ manent and heritable. Mutations could be of beneficial or of harmful types. Propagating material (seeds or cuttings) may be exposed to radiation and subsequently grown and observed for any chance beneficial mutations. Be­ cause mutations are relatively rare events and because the nature of the change is beyond the control of the experimenter, it is necessary to screen the plants from a large number of irradiated seeds or cuttings. Cuttings and seeds were exposed to radiation in the installation at the Central Agricultural Research Institute, Peradeniya. The ionizing radiation in the unit is obtained from a weak radioactive source of Cobalt 6 0, emitting gamma rays at 1.2 kilorads per hour. The material is placed in an eight-inch- cube chamber and different doses are obtained by varying the time of exposure. Doses ranging from 2.5 to 50 kilorads for cuttings and 25 to 60 kilorads for 54 ANNUAL REPORT FOR 1968 seeds were tested and" the treated material planted but. The- desirable dose for cuttings appears to be below 15 kilorads as those treated with higher doses have shown a very high percentage of mortality. With the dose range used for seeds, none of them germinated. This work is being continued. Controlled hand-pollination studies In contrast to some work reported earlier it was found that self-pollination gave as large a percentage of fruit set as that obtained by cross-pollination. The reasons underlying the apparently conflicting results merit investigation. The seeds obtained from these pollinations are being tested for viability in germination tests. Studies on floral development and effect of climatic conditions on flowering and fruit-set One hundred floral buds on each of five different clonal seed bearers were labelled every month, and their development closely followed through different stages in relation to flowering and natural fruit set. It is hoped to correlate such data obtained with prevailing weather conditions as well. The observa­ tions on the natural pattern of flowering and fruit-set should prove helpful in planning future breeding work. D . Janakiram CENTRAL NURSERY The Central VP Nursery which was under the charge of this Division was handed over to the Agriculturist in July 1968. All requirements of VP tea plants for the respective divisions will now be met by the Agriculturist. EXTENSION EXPERIMENTS Details of these experiments and some of the results obtained earlier has been presented in the Annual Report for 1967. XPH1 — Nitrogen at 4 levels with shade vs no shade as the main treatments at Liddesdale Group, Halgranoya — (1965) This tea was pruned in January 1968. Yields have not been recorded for a sufficiently long period in the new cycle for analysis and are, therefore, not presented. XPH2 — Nitrogen at 4 levels with shade vs no shade as the main treatments at Rothschild Estate, Pussellawa — (1965) This tea was pruned in June 1967 and the yields of the new cycle have been analysed and reported on below. XPH3 — Nitrogen at 4 levels with shade vs no shade as the main treatments at Mayfield Estate, Kotagala — (1965) The tea was pruned in December 1967 and is in the same stage of progress as XPH1. The results are, therefore, not presented. XPH4 — Nitrogen at 4 levels with shade vs no shade as the main treatments at Hauteville Estate, Agrapatana — (1965) Yields have.been recorded for a further periodiand the results reported on below. . . . ANNUAL REPORT FOR 1968 55 XPH5 Nitrogen at A levels with shade vs no shade as the main treatments at Blairlomond Estate, Udapussellawa — (1966) Yields have been recorded for a further period and the results are reported on below. XPH9— Nitrogen at 4 levels with shade vs no shade as the main treatments at Brunswick Group, Maskeliya — (1966) The tea was pruned in January. The analysed yield figures are presented below. XPH10 — Nitrogen at 4 levels with shade vs no shade as the main treatments at Morar Estate, Bogawantalawa — (1966) Forty eight post-treatment plucks have been recorded and analysed, and the results are presented below. XPH12 — Nitrogen at 4 levels with shade vs no shade as the main treatments at Oonoogaloya Estate, Kotmale — (1966) Forty six post-treatment plucks have been recorded and analysed and the results are presented below. XPH6 — Shade vs no shade at Rothschild Estate, Pussellawa — (1966) XPH7 — Shade vs no shade at Bogawana Group, Bogawantalawa — (1966) XPH11 — Shade vs no shade at New Peacock Group, Pussellawa — (1966) The results of experiments XPH6, XPH7 and XPH11 have still to be processed. The experimental plucking continued and the yields have been analysed for the number of plucks indicated against each experiment and are presented in Tables 12 and 13. In all the experiments the difference between shade vs no shade was in favour of the removal of shade. Nitrogen has had a significant promotive effect on yield at all locations. In XPH2, N 2 gave a significantly higher yield than those of the. other levels of nitrogen amongst which no difference was evident. There was no significant difference between the two higher nitrogen levels (240 and 360 lb per acre per annum) in experiment XPH4. In XPH5 there was no difference between the higher rates of nitrogen application, ie 200, 300 and 400 lb. A barely significant increase in yield of the third over the second nitrogen level was obtained (P < 0.05) at Brunswick (XPH9) and Morar (XPH10) while at Oonoogaloya (XPH12) the difference was significant at the 1% level of probability. It would be interesting to see whether the difference between second and third nitrogen levels and in the other experiments also would become significant with time as no significant difference was ob­ tained in the analysis reported previously. It is also of interest to note that reasonable yields were obtained at the zero level of nitrogen suggesting high residual effects of earlier applications. The period over which this will be effective will be of importance. The percentage increases in yield obtained with increasing levels of nitrogen both in the presence and absence of shade trees are presented in Table 14. It was reported earlier (Report for 1967) that although there was a ten­ dency for the response to nitrogen to be slightly better in the absence of shade trees in all the experiments, the difference was not significant in any of them. Analyses carried out after the experiment had progressed for a further period 56 ANNUAL REPORT FOR 1968 showed that in the experiments at Hauteville (XPH4) and Oonoogaloya (XPH12) there was a significant interaction between shade and level of nitro­ gen (P 0.05) indicating a greater response to nitrogen in the absence of shade. Whether this would be true for the other experiments as well in course of time, will be watched with interest. In experiments XPH1, XPH2, XPH3, XPH4, XPH9, XPH10 and XPH12 the levels of nitrogen are 0,120, 240 and 360 lb per acre per annum. In XPH5 the levels of nitrogen are 100, 200, 300 and 400 lb per acre per annum. TABLE 12 — Effect of nitrogen levels and shade trees on yield—All figures are calculated as made tea per acre per year on an absolute bush stand N o . o f Experiment Locat ion plucks — X P H 2 Rothschild 56 X P H 4 Hautevil le 64 X P H 5 Blairlomond 92 X P H 9 Brunswick 43 X P H 1 0 Morar 48 X P H 1 2 Oonoogaloya 46 Shade N o shade NO N l N 2 N 3 1850 1639 1895 1643 1614 1872 1943 2140 2367 2681 2628 2666 1720 1896 1957 2075 1770 1819 2138 2198 2347 1681 1843 1990 NO N l N 2 N 3 : 1743 1848 1960 1847 1644 1825 2245 2344 2839 2860 2861 2957 1776 2039 2102 2307 1955 2182 2292 2417 1280 1780 2089 2249 TABLE 13 — Effect of nitrogen and shade trees on yields at the different experimental sites (mean yields as lb made tea per acre per anmmi) on an abso­ lute stand (a) Nitrogen effects NO N l N 2 N 2 X P H 2 Rothschild 1796 1744 1927 1745 X P H 4 Hautevil le 1629 1849 2125 2242 X P H 5 Blairlomond 2604 2770 2745 2812 • X P H 9 Brunswick 1748 1963 2029 2191 • X P H 1 0 Morar 1862 2015 2215 2308 • X P H 1 2 Oonooga loya 1311 1730 1966 2119 (b) Shade tree effects Shade N o shade X P H 2 Rothschild 1757 1849 X P H 4 Hauteville 1892 2030 X P H 5 Blairlomond 2586 . 2879 X P H 9 Brunswick 1912 2054 X P H 1 0 Morar 1988 2212 X P H 1 2 Oonoogaloya 1714 1849 L S D ^ = 0 . 0 5 P = 0 .01 J» = 0.00.1 132 148 122 161 92 106 203 221 126' 145 Level of significance '• 5 % 5 % 0 . 1 % 5 % , 0 . 1 % 0 . 1 % 277 301 172 198 TABLE 14 — Percentage increase in'yields with increasing levels of nitrogen Shade trees present • N o N l ' N 2 N 3 N o N l N 2 X P H 2 Rothschild 100 89 102 89 100 106 112 X P H 4 Hauteville 100 116 120 133 100 111 137 X P H 5 Blairlomond 100 113 111 113 100 101 101 X P H 9 Brunswick 100 110 114 121 100 115 118 X P H 1 0 Morar 100 103 121 124 100 112 117 X P H 1 2 Oonoogaloya 100 125 137 148 100 140 163 Shade trees removed N 3 106 143 104 130 124 176 A , S. B. G o m e z ANNUAL REPORT FOR 1968 57 Acknowledgements The gift of samples of Gibberellic acid and Phyomone by Chemical In­ dustries (Colombo) Ltd, is gratefully acknowledged. Our thanks are due to Managers, Superintendents, Assistants and others on estates for their interest and^co-operation in the conduct of the extension experiments, and the Statis­ tics Department for the analysis of the results. Visits, Lectures and Symposia Dr V. S. Kulasegaram participated in a symposium on 'Drought' con­ ducted by the Institute at Badulla in November for the Uva Planters' Asso­ ciation. REPORT OF THE PLANT PATHOLOGY DIVISION Plant Pathologist — N. Shanmuganathan, BSc, PhD General The Head of the Division returned to Ceylon on 2nd October having worked overseas for a year. Dr R. L. de Silva acted for him in his absence. Mr P. V. Arulpragasam continued his post-graduate studies at Wye College, Kent, England. Mr W. R. F. Rodrigo left the service of the Institute on 30th June after spending six useful and productive years. He was replaced by Mr R. N. Bopearatchy who assumed duties on 1st August. Mr G. T. Karunasena, Labora­ tory Assistant, resigned his post and left the Institute on 31st March. Mr A. Chandrasekera, who succeeded him, also left the Institute on 30th September. Dr R. L. de Silva continued to function as the Co-Editor of the Institute's publications during the year. He was also in charge of the administration of the Institute's library. Fungicides for Phomopsis theae Using standard techniques, 11 fungicides were tested in the laboratory for their efficacy in controlling spore germination and mycelial growth of P. theae; the most effective were Du Pont 1991, Verdasan, Antimucin and Actidione. This work is being continued. The following experiments have been concluded : P l l , P23, P24, P25, P28, P31, P52, P53, P54, P57, P58, P59, P62, P63, P64, P65, P66, P67, P70, P71, P72, P73, P74, P78, P79, P80 and P82 Red Root Disease (Poria hypolateritia) P10 — Survival of P. hypolateritia in soil at different depths — (1964) The details of this experiment have been described in the Report for 1965. When root segments were retrieved after three years' burial, 76.6% of them still contained the pathogen in a viable state, but only 25.0% of these were able to infect young tea plants. The depth of burial had no significant effect on viability or infectivity. Full results are shown in Table 1. TABLE 1 — Viability and infectivity of root segments ret­ rieved after three years' burial in fallow soil Laboratory Investigations N . Shanmuganathan & R. N . Bopearatchy Fungicides for Monacrosporium ambrosium Work on this subject is presently in abeyance. Field Experiments and Trials Diameter of root segment (cm) Viability (%) Infectivity (%) 1 2 3 4 46.9 80.0 93.8 87.1 0 33.3 14.3 30.7 58 ANNUAL REPORT FOR 1968 59 After four years' burial only 46.6% of the root segments retrieved con­ tained viable P. hypolateritia mycelium. The results of inoculations with ,these root segments are not yet available. P l l — Resistance of clones to P. hypolateritia — (1964) Further observations have shown that none of the clones tested in this experiment (see Annual Report for 1964) is immune to the disease, although clone DUN 7 showed high resistance. This experiment is concluded. P13 — Selection of bushes resistant to P. hypolateritia at Mattakelle Estate, Talawakele — (1964) It was possible to raise plants from only eight of the ten clones selected on the field. Plants raised from these eight clones were planted in pots and inoculated with P. hypolateritia. Observations to date show that two of these clones are susceptible to the disease. The experiment is continuing. P31 — Control of P. hypolateritia in tea stumps using methyl bromide—(1966) Details of the experiment are given in the Annual Reports for 1966 and 1967. The efficacy of the treatments was finally assessed by planting one-year- old tea plants in the plots. A year after planting the number of stumps that were infective in each plot was recorded. Results showed that all the control plots and two others that received the half pound treatment had infected stumps, while the remaining plots had none. It is concluded that for complete control of P. hypolateritia within large tea stumps, the soil should be fumigated with at least one pound of methyl bromide per 100 sq ft. P45 — Resistance of clones to P. hypolateritia — (1966) Results of this experiment in which 19 clones are being tested for resis­ tance to the disease are not yet available. • P53 — Selection of bushes resistant to P. hypolateritia at Le Vallon Group, Pupuressa — (1966) i All the six clones tested in this experiment have been found to be suscepti­ ble to the disease. The experiment is concluded. i P55 — Studies on inoculum potential—Quantity of inoculum and age of host plants on the infection of tea by P. hypolateritia — (1967) The experiment is continuing. P56 — Soil fumigation with methyl bromide on soil nitrogen, soil microflora, and the growth of tea and Guatemala Grass -— (1967) ' This experiment is continuing. 1 P69 — Resistance of clones to P. hypolateritia — (1967) The plants in this experiment (see Annual Report for 1967) have been inoculated, but results are not yet available. , N . S h a n m u g a n a t h a n & S. R . A . F e r n a n d o 60 ANNUAL REPORT FOR 1968 1968 Experiments P75 — Control of P. hypolateritia by soil treatment with chloropicrin—2 repli­ cates of 3 treatments + control — (1968) In this experiment, two rates of chloropicrin, viz 10 ml per sq. ft (3.7 lb per 100 sq. ft) and 20 ml per sq. ft (7.4 lb per 100 sq. ft) were compared with the standard rate of methyl bromide (0.5 lb per 100 sq. ft) for efficacy against Pi hypolateritia. The chloropicrin was applied to the soil nine inches below the surface using injector guns, and plots were covered with polythene sheeting after application. The efficacy of the treatments was assessed by burying infected root segments in the plots before fumigation and retrieving i them and determining their viability seven weeks after fumigation. The results showed that all three treatments were fully effective in controlling P. hypolateritia. It is intended to test lower rates of application of chloropicrin in 1969. P76 — Studies on inoculum potential—Determmation of the smallest effective inoculum for infection of young tea plants by P. hypolateritia — (1968) To determine the effective inoculum potential of one-year-old plants, potted plants of clone TRI 2024 have been inoculated with inocula of different volumes. Twelve different volumes have been used by selecting root segments of varying diameters and lengths (cf P46, Annual Report for 1966). The experiment is progressing. S. R. A. Fernando & N . Shanmuganathan Root diseases of tea P57 — 3 doses of methyl bromide for the control of Ustulina deusta, Rosellinia arcuata, Fomes lignosus and Fomes noxius— (1967) All three doses of methyl bromide tested in this experiment, viz, \, i, 1 lb per 100 sq. ft, gave 100% control of U. deusta down to a depth of two ft, but only the half and one lb treatments were fully effective against R. arcuata. The latter observation confirms earlier results (cf P44, Annual Report for 1966). The efficacy of the treatments against F. lignosus and F. noxius could not be assessed accurately because many of the control inocula were also found to have lost their viability after recovery from the soil. The experiment will be repeated with the Fomes spp. in 1969. S. R. A. Fernando & N . Shanmuganathan Blister Blight {Exobasidium vexans) P14 — Epidemiology of Blister Blight — (1962) An experiment was carried out to determine whether the spores caught in the Hirst trap came mainly from the unsprayed area immediately surrounding it or whether they came from further away. Two traps were run, one each, in the centre of two adjoining unsprayed areas. The tea in one of these areas was progressively pruned starting from the centre, and the catches in the two traps compared. Results showed that there were no significant differences in the number of spores caught by the two traps even after a ring of 18 bushes had been pruned around one trap, implying that the majority of the spores caught in the traps did not come from the immediate vicinity. N . Shanmuganathan & T. V. Saravanapavan ANNUAL REPORT FOR 1968 61 P26 — Loss of crop caused by Blister Blight on unshaded seedling tea—(1966) This experiment began its third year of plucking in April, and in June the tea was four years old from pruning. It was decided to extend the pruning cycle for a fifth year in order to assess crop loss caused by Blister Blight with increasing age from pruning. Pruning is due in 1969. A reappraisal of the results will be undertaken at the completion of the pruning cycle. R. L. de Silva & S. Murugiah P30 — Loss of crop caused by Blister Blight on unshaded VP tea (Clone TRI 2024) — (1966) This experiment began its second year of plucking in July. It was found that infection levels are higher on VP tea than on seedling tea sprayed with the same dose of fungicide. This is probably because VP tea has more plucking points and the area to be covered by the fungicide is, therefore, greater than it would be with seedling tea. An appraisal for crop loss will be made at the end of the pruning cycle, which will be 1970. R. L. de Silva, T. V. Saravanapavan & S. Murugiah P58 — Nickel and copper fungicide mixture for the control of Blister Blight on VP tea — (1967) The differences between treatments failed to reach significance and the experiment was abandoned^ This experiment will be repeated'-as soon as it can be fitted into the experimental programme on Blister Blight. Some of the treatments are included in Experiment P77. P59 — Blister on tea flush — (1967) Assessments of Blister Blight were made on factory leaf (units of two leaves and a bud). It was found that when conditions were conducive for infection, latent blisters appeared as translucent spots on five to ten % of the shoots but no sporulating blisters were found on flush units of two leaves and a bud. In the case of single-leaf soft banji, however, 20 to 40% of the shoots often had sporulating blisters. This is understandable because the leaves on a banji shoot are much older than those on flush shoots. Earlier observations that blisters that do not reach sporulating age on flush, cannot affect the made tea are confirmed. This experiment is concluded. R. L. de Silva P60 — 2 levels of nitrogen, 4 levels of infection of Blister Blight and 3 levels of shade on yield of 2 clones (TRI 2025 and TRI 2023) — (1967) This experiment was planted out in 1967 and, in the year under review, shade trees were planted on all the plots, there being nine dadap (Erythrina lithospermd) trees per plot. Pre-treatment records will be taken when the plants have reached full bearing and the shade on the low-shade and no-shade plots will then be removed for treatments to commence. This would probably be in 1971. R. L. de Silva, T. V. Saravanapavan & S. Murugiah P61 —- Protection of tea against Blister Blight by disease forecasting — (1967) This experiment was continued on No. 14 Field at St Coombs. Spraying was done according to the forecast of the infection in this field. Arxording to this scheme when predicted infection is high, nickel chloride is sprayed; when 62 ANNUAL REPORT FOR 1968 it is moderate, copper formulations are used, and when it is low, no spraying is done. According to this scheme the following spraying rounds were applied during the year under review: Nickel chloride — 9 rounds Copper formulations — 4 rounds The experiment is continuing. R. L. de Silva, W. R. F . Rodrigo & T. V. Saravanapavan 1968 Experiment P77 — Fungicides for the control of Blister Blight on VP tea—Randomized blocks — (1968) Two new fungicides were tested for their efficacy in controlling Blister Blight. The first was a formulation of copper oxychloride and nickel chloride and the second was Du Pont 1991, reported to have systemic properties. Al­ though the latter should be applied to the roots, in this experiment it was sprayed on the leaves together with the surfactant supplied by the manufac­ turers, in two volumes of water. The test fungicides were compared with the performance of nickel chloride, nickel sulphate hexahydrate, and a standard cuprous oxide formulation. Results are not yet available. R. L. de Silva, T. V. Saravanapavan & S. Murugiah Collar and Branch Canker in young tea (Phomopsis theae) UP7 — Resistance of clones to P. theae at Nayabedde Estate, Bandarawela — (1964) One assessment for canker incidence was carried out during the year on the clones under test (see Annual Report for 1965). The three clones that suffered most from P. theae cankers were TRI 2024, UH 9/3 and NL 3/1. The experiment is continuing. UP8 — Resistance of clones to P. theae at Glen Devon Estate, Halgranoya — (1965) The 20 clones in this experiment (see Annual Report for 1965) were exa­ mined for cankers in March, and only clone KEN 16/3 had cankers on 15 bushes. The experiment is continuing. P18 — Clonal resistance, pathogenecity of isolates of P. theae and effect of age of bushes on disease development — (1964) The yearly inoculations in this experiment, the details of which are given in the Annual Reports for 1965 and 1966, could not be carried out in 1968. The last series of inoculations will be carried out in 1969. P62 — 3 fungicides for the control of?, theae on Clone 77*72024 at St Leonards Estate, Halgranoya — (1967) The three fungicides tested in this experiment were Santar A (yellow mercuric oxide), Fomac (pentachloronitrobenzene) and Bordeaux mixture (4:4:50). Statistical analysis of the final results showed that the application of Santar A and Bordeaux mixture caused a significant reduction in the number of collar cankers as compared to the control; but none of the three fungicides :had any significant effect on branch cankeits! Fomac was also found.to be phytotoxic. The experiment is concluded. ANNUAL REPORT FOR 1968 63 P63 — 3 fungicides for the control of P. theae on clone TRI 2024 at Liddesdale Group, Halgranoya — (1967) The three fungicides tested were the same as in P62. Analysis of the final results showed that there were no significant differences between the treat­ ments and the control in regard to canker incidence. The experiment is con­ cluded. P64 — 3 fungicides for the control of P. theae on clone KP9 at Concordia Group, Kandapola — (1967) The same three fungicides were tested as in P62. Final results showed that none of the fungicides was effective in controlling collar or branch canker. The experiment is concluded. P65 — 3 fungicides for the control of P. theae on clones TRI 2025 and N3 at Craig Estate, Bandarawela — (1967) The fungicides tested were the same as in P62. In this experiment, the application of Santar A resulted in a significant reduction in the number of collar cankers compared with the control, but it had no effect on branch cankers. Both Fomac and Bordeaux mixture were, however, ineffective against collar as well as branch cankers. The experiment is concluded. P66 — So/7 covers on soil moisture and incidence of Collar and Branch Canker Disease at St Leonards Estate, Halgranoya — (1967) Details of this experimentVe given in the Annual Report for^f967. Final results showed that plots covered with polythene had significantly less can­ kers than those left uncovered (control) or thatched with Mana grass (Table 2). There were also fewer deaths resulting from attacks by P. theae in the poly­ thene covered plots compared with the other two treatments but the difference was not significant statistically. TABLE 2 — Incidence of P. theae on plots covered variously Cover Mean No. of cankers No. of dead (transformed data) plants Polythene 1.80 3 Mana grass 2.61 15 Uncovered 2.49 19 LSD (P = 0.05) 0.67 NS Soil moisture determinations on the plots carried out weekly for two months proved inconclusive probably because of large errors in sampling. The ex­ periment is concluded! i» N . Shanmuganathan & W. R. F. Rodrigo 1968 Experiments P70 — 3 fungicides for the control of P. theae on clone DG 39 at Delmar Estate, Halgranoya—5 replicates of 3 treatments + control in randomized blocks - (1968) • : .« The three fungicides tested in, (this experiment were Antimucin (a phenyl mercury compound), Santar A andi Kanderdood (a mercury-based: paint), j The: ates and methods of application were as follows.: 64 ANNUAL REPORT FOR 1968 Antimucin — One fluid ounce per gallon of water; sprayed on the collar and frame Santar A — One kg in 2\ gallons of water; sprayed on the collar and frame Kankerdood — Applied as a paint with a brush to the collar and lower parts of the frame. All treatments were applied once each month from June to October. Final results were recorded in December, and statistical analysis revealed that none of the treatments was effective in reducing canker.incidence, although Antimucin appeared promising (Table 3). TABLE 3 — Control of P. theae with three fungicides Fungicide No. of cankers (transformed data) Antimucin 1.31 Santar A 1.46 Kankerdood 2.65 Control 1.87 LSD (P = 0.05) 0.67 P71 — 3 fungicides for the control of P. theae on clones TRI 2022 and TRI 2027 at Cfaig Estate, Bandarawela — 6 replicates of 3 treatments + control in randomized blocks — (1968) The three fungicides used and the rates and methods of application were the same as in P70. The treatments were applied once each month from June to November. Statistical analysis of the final results recorded in December showed that while Antimucin was effective in reducing canker incidence signi­ ficantly, both Santar A and Kankerdood were ineffective (Table 4). TABLE 4 — Control of P. theae with three fungicides Fungicide No. of cankers (transformed data) Antimucin 1.82 Santar A 4.23 Kankerdood 3.45 Control 3.03 LSD (P - 0.05) 1.17 P72 — 3 fungicides for the control of P. theae on clone TRI 2026 at Liddesdale Group, Halgranoya — 5 replicates of 3 treatments + control in ran­ domized blocks — (1968) The details of this experiment are identical to those of P70. None of the treatments gave significant control of the disease in this experiment. P73 — 3 fungicides for ihe control of P. theae on Clone DG39 at Gordon Estate, Uda Pussellawa — 5 replicates of 3 treatments + control in rando­ mized blocks — (1968) The details of this experiment are identical to those of P70. . None of. the treatments gave significant control of the disease in this experiment:. ANNUAL REPORT FOR 1968 65 R. L . de.Silva & L . A Seevarataam P74 — 3 fungicides for the control of P. theae on clone St John's 16 at Park Group, Kandapola — 4 replicates of 3 treatments + control in rando­ mized blocks —. (1968) The three fungicides tested in this experiment were Santar A, Fycol (oil- based copper fungicide + nickel chloride) and Verdasan (phenyl mercuric acetate). Fycol and Verdasan were applied as a spray to the collar and frame at the rate of three oz per gallon and four oz per gallon respectively. Santar A was applied as in P 7 0 . None of the three fungicides tested was effective in reducing canker incidence significantly in this experiment S. R. A . Fernando & N . Shanmuganatban P82 — Depth of root penetration on the incidence o /P . theae — Paired bushes, one of each pair being infected and the other healthy — (1968) This experiment has been concluded and the results published (de Silva & Fernando 1968). R. L. de Suva & S. R. A . Fernando Root disease and shade trees P32 — Killing Grevillea robusta trees by Phortox treatment andby ring-barking — 0966) Details of this experiment are given in the Annual Report for 1966. The following observations were made during the year : Treatment 1 — Phortox 5%—Eight trees were completely dead in this treatment, while four were in various stages of defoliation. The remaining 13 trees did riot show any obvious signs of death. 2 — Phortox 2-5%—Only two trees in this treatment died during the year, while another two were heavily defoliated. The remaining 21 trees showed no apparent signs of death. 3 — Ring-barking—23 trees in this treatment died during the year and the remaining four were defoliating. Up to the end of 1968, 12 estimations of root reserves had been carried out, and results indicated that a significant reduction in reserves had occurred only in the ring-barked trees as compared with the controls. All dead trees have been inoculated with U. deusta, but results are not yet available. The experiment is continuing. N . Shanmuganathan, P. V. Arulpragasam & T. V. Saravanapavan P20 — Incidence of root diseases in tea following removal of shade trees by various methods — (1965) G. robusta trees on various fields of St Coombs Estate were felled (a) after ring-barking and complete defoliation, and (b) without ring-barking. No cases of tea root diseases were detected arising from the ring-barked trees during the year, while four patches of U. deusta were detected in the stumps of trees which had been felled without ring barking. Records continue to be maintained. , :'.. 66 ANNUAL REPORT FOR 1968 OUspot, Disease .... P21 — Rate of spread of OUspot Disease at Pedro Group, Nuwara Eliya (1964) No assessments were made during the year, but the experiment will be retainediibr future assessments. . . R. L. de Silva & P. V. Arulpragasam Phloem Necrosis Virus Disease P23 — Search for indicator clones at Eskdale Estate, Kandapola — (1960) Ten low-jat clones which were planted in 1960 have so far shown no symp­ toms of the disease. The experiment has been in progress for eight years. Even if any of these clones develop symptoms in the future, they would be of little use as indicators. The experiment is, therefore, concluded. P24 — Se4dtransmission:'— (1960) One seedling out of 25 from diseased bushes planted in 1958 showed symptoms of the disease after nine years. The experiment is now concluded. P27 — Tolerance of clones to Phloem Necrosis Virus Disease at Pedro Group, Nuwara Eliya — (1966) One hundred and forty six clones were planted in November 1966 and are under observation for symptoms of the disease. The details of the clones are given in the Annual Report for 1966. The plants are due to be tipped in early 1969. The experiment is continuing. R. L; de Silva Stem Cankers on low-grown clonal tea LP3 — Rate of spread of cankers at Millakande Estate, Bulathsinhala—(1964) ^ No assessments of cankers were carried out during the year but the ex­ periment will be retained for future investigation. R. L. de Silva Mechanical Harvesting of tea P28 — Hand, machine and shear plucking on tea yield and quality — (1966) P29 — Hand, machine and shear plucking oil tea yield and quality —- (1966) P67 — Hand, machine and shear plucking on yields and manufacturing proper­ ties of low jat seedling tea at Pedro Group, Nuwara Eliya — (1967) * Experiments P28, P29 and P67 have been concluded and have been re­ ported in the Report of the Technology Division for 1967 under experiment numbers T18; T19 and T26. R. L. de Silva, S. Murugiah and the Technology Div is ion Asphyxiation of tea roots P52 — Depth of planting holes on growth — (1966) This experiment has been concluded and the results published (de Silya & Seevaratnam 1968). j ..... ) R. L. de Silva & L. A . Seevaratnam ANNUAL REPORT FOR 1968 67 Miscellaneous P68 — Methyl bromide for the control ofCouch Grass — (1967) It was found that methyl bromide at the dose of two lb per 100 sq. ft of ground controlled a heavy stand of Couch Grass extremely well. No new Couch Grass has been observed on the area for almost two years. It is possi­ ble, however, that lower doses may be effective although this was not'tested. It is also possible that on other types of soil, the dose of two lb may not be sufficient. This experiment is concluded. R. L. de Silva & L. A . Seevaratnam P78 — Porosity of soil mixtures adjusted by the use of coarse sand on the growth of young VP tea plants in polythene sleeves — 20 replicates of 4 treat­ ments in randomized blocks — (1968) The four treatments were subsoil and cdarse sand mixed in the propor­ tions 1:1, 1:2, 1:3 and 1:4. It was found that root growth was best, where the highest proportion of sand was used. The roots tended to grow into the body of the soil rather than, remain in-between the polythene sleeve and the soil, when the proportion of coarse sand used was greater. This experiment has been reported on earlier (de Silva & Seevaratnam. 1968) and is now con­ cluded. P79 — Porosity of soil mixtures adjusted by the use of compost on the growth of young VP tea plants in polythene sleeves-20 replicates of 4 treatments in randomized blocks — (1968) The treatments were similar to those used in experiment P87, except that compost was used instead of sand. Again, it was found that root growth was best when subsoil and compost were mixed in the proportion of 1:4. The results of this experiment have been publised (de Silva & Seevaratnam 1968) and is now concluded; P80 — Effect of aeration on the growth of yegetatively-propagated nursery plants growing in polythene sleeves in clayey soil — 20 replicates of 4 treatments in randomized blocks — (1968), The plants of Clone DT 1 selected for this experiment were exhibiting poor growth in clayey soil. There were three treatments as follows : 1—Bags were picked up and pressed in from the sides in order to break up the clay and improve soil aeration. 2 — Using a round iron rod 7 mm in diameter and pointed at one end, the soil in each bag was stalled six times from above so that the rod penetrated to the bottom of the soil, thereby, improving'the drainage of water from the soil. It was found that the treatments 1 and 2 resulted in greatly enhanced root growth whereas the growth in the untreated controls continued to remain poor. The results have been published (de Silva & Seevaratnam 1968) and the experi­ ment is< now concluded. R. 'L..de Silva & L. A . Seevaratnam P81 -r- Forking the soil on the growth of Clone TRI 2142 planted in heavy soil — 14 paired plots — (1968) In this experiment the effect of forking the soil to a depth of 18 inches is being compared with no forking. The growth of the tea is assessed visually. 68 ANNUAL REPORT FOR 1968 The plots are arranged in pairs, one of each pair being forked and the other left unforked. The plots were forked once in late 1968. The results are not yet available. R. L. de Silva & R. N . Bopearatchy New observations and records Charcoal Stump Rot of Eucalyptus robusta Ustulina deusta was recorded, apparently for the first time in Ceylon, on Eucalyptus robusta stumps at St. Coombs. E. robusta is the most common species of gum planted on tea estates in Ceylon. The disease was observed on the stumps and roots of three-year-old trees felled without prior ring-barking. Fructifications, which were abundant on the stumps, were similar to those found on tea stumps affected by Charcoal Stump Rot. Leaf Spot of Crotalaria anagyroides An unidentified fungus was found to attack young plants of C. anagyroides at St. Coombs. The fungus forms grey to black, sharply defined, irregular spots on the leaves and lesions on the stem. The spores of this species are similar to those of Pestalotia theae found on tea. The same fungus was also found on diseased C. anagyroides plants sent to the Institute from an estate in the Kandy District, The disease is under investigation. Acknowledgements The co-operation of the Agency Houses, Managers and Assistants of estates in the conduct of the experimental programme, and the co-operation and assistance of the staff of the Division are gratefully acknowledged. Thanks are also due to commercial firms that supplied free samples of fungicides for experimentation. Visits, Lecturers & Symposia etc Lectures KERR, A. & D E SILVA, R. L. — "Epidemiology of tea Blister Blight (Exobasi- dium vexans)". Paper read at Symposium on "The Epidemiology of Leaf Diseases in the Humid Tropics" organized by the First In­ ternational Congress of Plant Pathology in London in July. PERIES, O. S. & D E SILVA, R. L. — "Problems of crop disease control with chemicals". Paper read at the Symposium on "Crop Protection" organized by the Ceylon Association for the Advancement of Science held in Colombo in December. SHANMUGANATHAN, N. — "Studies on the parasitism and control of tea root disease fungi in Ceylon". Paper read at the Symposium on "Root Diseases of Plantation Crops" organized by the First International Congress of Plant Pathology in London in July. SHANMUGANATHAN, N. & FERNANDO, S. R. A. — "Effects of soil fumigation with methyl bromide on root diseases of tea and the nitrogen status of tea soils". Paper read at the 24th Annual Sessions of the Ceylon Association for the Advancement of Science held in Colombo in December. ANNUAL REPORT FOR 1968 69 Dr N. Shanmuganathan and Dr R. L. de Silva wish to thank Dr A. Kerr for reading their papers at the First International Congress of Plant Pathology held in London in July, which they were unable to attend. Symposia Dr N. Shanmuganathan and Dr R. L. de Silva participated in the Sympo­ sium on Drought held at Badulla in October for the Uva Planters' Association. Publications D E SILVA, R. L. (1968). Agricultural Research. Vidumina of 19th June 1968 (InSinhala). ,| D E SILVA, R. L- (1968). Tea. In a Supplement on Agriculture and Industry. The Times of Ceylon of 30th November 1968, 32 pp. DE SILVA, R. L. & FERNANDO, S. R. A. (1968). The influence of shallow top- soil on the incidence of Collar and Branch Canker Disease of tea (Phomopsis theae Petch). Tea. Q. 39, 87-91. D E SILVA, R. L. & SARAVANAPAVAN, T. V. (1968). Tea Cider : A potential winner. Tea Q. 39, 37-41. D E SILVA, R. L. & SEEVARATNAM, L. A. (1968). The importance of soil air for tea root growth. Tea Q. 39, 42-49. SHANMUGANATHAN, N. & D E SILVA, R. L. (1968). Susceptibility of tea clones to Collar and Branch Canker Disease of tea (Phomopsis theae Petch). Tea Q. 39, 92-93. SHANMUGANATHAN, N. (1968). Root diseases of tea and their control, Tea Res. Inst. Ceylon, Advisory Pamphlet 2/66. 12 pp. + 9 col.pl. REPORT OF THE NEMATOLOGY DIVISION Nematologist—P. Sivapalan^ BSc, PhD General - The yacancy created by Mr. H. B. Herath's transfer to the Entomology Division in October 1967, was filled by the appointment of Mr V. Shivananda- rajah in August 1968. As the Division was short of staff the services of Mr P. A. John, who was due to retire in October 1968, were extended by one year. Laboratory Investigations Methodology Earlier findings indicated that storage of soil-samples in the laboratory, resulted in a build up of eelworm numbers within samples. Further investi­ gations have shown that this observed increase was due to an increased acti­ vation of worms that resulted in a higher percentage recovery than the usual 20 per cent. As the recovery technique depends on the activity of the worms, temporary storage at a slightly higher temperature than that in the field, re­ sults in an increased activity and consequently, a larger percentage is recovered. This technique of "storing and, recovery", has proved useful to detect the exis­ tence of eelworm in areas where the population level has dropped below the threshold value, of the "normal detection level," as for instance, following a period; of rehabilitation under Guatemala grass. p . A . J o h n Biochemicalinvestigations , •' .' Laboratory investigations into the biochemical aspects of resistance of tea clones,to eelworm pathogenicity, have indicated that there is a significant reduction in, the amino acid theanine (an amino acid specific to tea) in roots infested with eelworms. No such obvious reduction in this amino acid was observed in clones tolerant or resistant to eelworms. When investigating the free amino acid pattern within nematode tissues, glutamine and glutamic acid, were found to be the most predominant and these two amino acids also happen to be the major derivatives of theanine. The latter appears to play a signi­ ficant role in the metabolism of this eelworm. As these are interesting observations, further investigations are being carried out. V. Shivanandarajah Field Experiments and Trials The following experiments have been completed and the results have been published in the Annual Report for 1967, Part 2, pp 79-87: N7, N12, N14, N15, N16, N21, N23, LN2, MN1 and UNI. N l — Resistance and tolerance of clones to Pratylenchus loosi — (1962) Thirty six clones were screened for resistance and tolerance in 1968 but the assessments have not been completed, and the results cannot, therefore, be quoted yet. N3 — Field performance of clones tolerant to P. loosi — (1964) 70 ANNUAL REPORT FOR 1968 71 • The results of yield analysis are presented in Tables 1. and 2. TABLE 1 — Field performance of clones tolerant to P. loosi Mean yield (lb green leaf per plot) Mooloya Clone Estates* St Coombs Derryclare M241 103.9 88.6 63.5 M116 59.7 108.1 55.7 2142 61.4 75:0 94.9 2025 125.8 125.7 94.4. M208 58.9 86.9 53.9 DTI 88.6 93.7 56.3 LSD P = 0.05 23.6 33.5 4.6 P = 0.01 32.6 6.3 P = 0.001 45.0 8.7 *The plots at Chapelton Estate were pruned in May 1968. An analysis on yield could not, therefore, be worked out. As seen from Table 1, a highly significant difference in yield was observed between clones at St Coombs and at Mooloya. A Combined statistical analy­ sis of yield patterns, indicated a highly significant difference between locations and a highly significant treatment x location interaction, indicating that the clones behaved differently at the different test locations (vide Table 2). TABLE 2 — Locational performance of clones tolerant to P- loosi Estates Mean Yield ( lb green leaf per plot ) 9 6 . 3 2 8 3 . 0 4 6 9 . 7 8 9 . 1 7 12 .21 15 .93 115 .28 8 5 . 3 3 7 9 . 5 3 7 7 . 0 9 7 4 . 4 8 6 6 . 5 4 1 2 . 9 6 1 7 . 2 7 All the clones yielded best at Derryclare Estate and least at Mooloya Estate. TRI 2025 yielded best at all locations, yielding, on an average, a little over 2000 lb made tea per acre per year, in the third year of plucking of the first cycle. This yield was found to be (highly) significantly greater than all the other test clones. TRI 2025 was followed by M 241 yielding, on an average, a little over 1500 lb made tea per acre per year. All the other test clones were found to yield less than 1500 lb, with M 208 yielding the least (1200 lb). Derryclare St C o o m b s Mooloya L S D ( P = 0 . 0 5 ) ( P = 0 . 0 1 ) ( P = 0 . 0 0 1 ) Clones T R I 2025 M 2 4 1 D T I T R I 2142 M 116 M 2 0 8 L S D ( P = 0 .05 ) ( P = 0 . 0 1 ) 72 ANNUAL REPORT FOR 1968 The results of assessments of eelworm numbers are presented in Tables 3 and 4. TABLE 3 — Build-up of soil populations of P. loosi among the test clones—Analysis done for individual estates G o n e Mean count per 100 g soil (log n + 1 transformed) : Estates St C o o m b s Derryclare Chapelton Mooloya M 241 0 .845 1 .490 1.817 0 .525 M 116 0 . 7 6 2 1 .540 1 .620 1.605 2142 0.-880 1 .072 1 .745 0 . 6 0 0 2025 1 .097 1 .460 1 .778 0:885 M 2 0 8 0 . 2 7 0 1 .240 1 .427 L 2 7 5 D T I 0 .735 ; 1.475 1 .640 0 .975 L S D (P = 0 . 0 5 ) 0 . 9 6 5 0 . 5 6 7 0 . 5 4 2 0 . 6 9 0 (NS) (NS) (NS) AS seen from Table 3> no significant difference in the build-up of the eelworm population in soil was observed in respect of the different test clones, other than at Mooloya Estate, where a significant difference was observed between the clones M 241 arid 208. From a combined statistical analysis, however, it could be concluded that there is no significant difference between the test clones, in respect of eelworm multiplication, (vide Table 4). TABLE 4 — Build-up of soil populations of P. loosi among the test clones—combined analysis for all estates Estates Mean population count per lOOg soil Moo loya 1 .67 Derryclare 1.37 Chapelton 0 . 9 7 St Coombs 0 . 7 6 L S D (P = 0 . 0 5 ) ( / » = 0 . 0 1 ) ( P = 0.001.) 0 . 2 8 0 . 3 7 0 . 4 7 Clones M 116 T R I 2025 D T I M 241 T R I 2142 M 2 0 8 1.38 1 .30 1 . 2 0 1 .16 1.07 1 .05 L S D (P = 0 . 0 5 ) (NS) ANNUAL REPORT FOR 1968 73 A highly significant Ideational variation was, however, observed in res­ pect of eelworm multiplication. This could be due to variations in soil con­ ditions, which in turn have a direct influence on the rate of eelworm: multipli­ cation. According to the observations, the soil conditions at Mooloya seem to be the most favourable, and that at St Coombs the least favourable for rapid eelworm build-up. (The poor performance of the test clones at Mooloya, could probably result from this rapid build-up of eelworms.) The plots at St Coombs and Mooloya are due for pruning in 1970. The plots at Derry- clare Estate were pruned in January 1969. Assessments will be continued for the second cycle. S. Samarajeewa & P. A. John N8 — The effect of two methods of uprooting on (a) survival of P. loosi during the rehabilitation period and (b) the increase of P. loosi following re­ planting — (1965) The results of assessments are presented in Table 5. TABLE 5 — Means of assessments of shoot and root growth of replanted tea and mean counts of eelworm build-up within roots Treatments Shoot weight Root weight Eelworm count Hand pulled 112 .6 2 6 . 3 1 .24 Winched 152 .5 . 3 4 . 4 1 .04 L S D ( P = 0 .05) 5 3 . 8 11 .3 0 .91 (NS) (NS) CNS) Although there is no significant difference between treatments in respect of shoot and root growth and eelworm build-up in roots, in general, there is a trend towards a better growth of plants and a lower eelworm build up, in the winched plots than in the hand-pulled plots. Winching out of old tea bushes, by itself, is not a satisfactory method of uprooting; deep forking, and root removal must necessarily follow the winching out of bushes, particularly, when the land is to be rehabilitated under Guatemala grass. S. Samarajeewa & A. R. M. Hassim N13 — Fertilizer levels and their effects on the build-up of populations of P.. loosi in tea (TRI 2025) — (1966) As all the pots were inoculated with eelworms, the extent of pathogenicity in respect of the different fertilizer treatments, could not be evaluated. The results of analysis of shoot and root growth and nematode counts within roots, are presented in Table 6. As seen from Table 6, a highly significant response to nitrogen and potas­ sium was observed in respect of both shoot and root growth. No significant response to phosphorus was observed with respect to shoot growth and only a small response was observed with respect to root growth. The results of this investigation indicate that potassium may be important for improving the growth of eelworm infested plants. In order to assess possible variations in the extent of pathogenicity, the above experiment is repeated with modifica­ tions (vide N17). S. Samarajeewa, A. R. M. Hassim & P. A. J o h n 74 ANNUAL REPORT FOR 1968 S. Samarajeewa, A. R. M. Hassim & P. A. John TABLE 6 — Performance of clone TRI 2025 in respect of different fertilizer treatments and eelworm infestatian Fertilizer Shoot weight R o o t weight Eelworm count treatment (g) (g) per g root (Nitrogen levels) (sq root trans) ( lb per acre per year 0 4 8 . 6 6 0 . 3 10 .54 60 160 .5 129 .9 1 2 . 4 0 120 2 1 4 . 4 182 .7 7 . 9 4 180 1 9 3 . 2 173 .9 9 .68 L S D (P = 0 . 0 5 ) 3 1 . 4 3 1 . 7 2 . 5 7 ( P = 0 . 0 1 ) 4 1 . 8 4 2 . 1 3 . 4 2 (P = 0 .001) 5 4 . 2 5 4 . 7 (NS) (Phosphorus levels) (lb per acre per year) 0 142 .7 128 .2 10 .72 30 150 .9 125.1 1 0 . 6 0 60 1 6 8 . 9 156 .7 9 .11 L S D (P = 0 .05 ) 2 7 . 2 2 7 . 4 2 .91 (NS) (NS) (Potassium levels) ( lb per acre per year) 0 131 .2 115 .5 10 .03 35 161 .7 135 .6 10 .82 70 1 6 9 . 6 1 5 9 . 0 9 .57 L S D (P = 0 .05) 2 7 . 2 2 7 . 4 2 .91 (P = 0 . 0 1 ) 3 6 . 2 3 6 . 5 (NS) N17 — Fertilizer levels on the build up and pathogenicity of P. loosi in tea — (1967) The results of this experiment indicate that although there was a response to nitrogen in both the infested and uninfested plants, the degree of pathogenicity, increased with increasing nitrogen application. Elemental analysis of both leaves and roots indicates that with increasing nitrogen, the percentage of potassium decreased markedly, in both leaves and roots (see Table 7). TABLE 7 — Results of elemental analysis and assessments of pathogenicity Mean % K Mean reduction Mean % K Mean N e m a t o d e count Levels o f N in leaves in shoot growth in roots reduction per g root (lb per acre in root . (log transformed) per year) growth 0 1 .46 4 . 6 1.76 6 4 . 7 2 .91 15 1.21 6 9 . 5 1 .19 129 .3 2 . 8 9 30 1 .20 6 7 . 9 1 .48 142 .3 3.01 60 1 .06 9 9 . 7 0 . 9 8 1 4 2 . 6 3;05 120 0 . 5 3 1 3 7 . 2 0 .55 160 .3 3 . 2 0 L S D C P = 0 . 0 5 ) 7 1 . 6 0 . 4 9 8 8 . 9 0 . 2 3 ( P = 0 . 0 1 ) 0 . 3 4 — 0 . 6 8 — — ( / > = 0 . 0 0 1 ) 0 . 4 7 — — — — .. The decrease in potassium within leaves and roots was found to be in­ versely proportional to the increase in pathogenicity. Potassium, therefore, appears to be playing a significant role in nematode pathogenicity. Lowering of the potassium content within the host plant appears to be enhancing damage caused by eelworms. Details of this investigations will be published shortly. ANNUAL REPORT FOR 1968 75 N18 - T - 4 levels of application of Nemagon granules (20% w/w) infested nursery soil, on the growth of cuttings and the population build up o/P.loosi in roots of clone TRI 2024 — (1967) No significant difference in growth rates of cuttings was observed between those planted in soil mixed with Nemagon at the different rates of application, and the controls. At the eight month, the majority of the cuttings had deve­ loped only a few roots and most of them had callused heavily. Mixing nur­ sery soil with Nemagon granules, therefore, does not seem to be useful. This experiment is now terminated. A. R. M. Hassim N19 — Selective removal of old tea roots of varying sizes, followed by a period of rehabilitation, on the subsequent growth of tea plants and eelworm build up within roots at Ferham Estate, Lindula — (1967) The Guatemala grass was uprooted and the plots were planted to tea in August 1968. This experiment is continuing. S. Samarajeewa N20 — Selective removal of old tea roots of varying sizes, followed by soil fumigation without a period of rehabilitation, on the subsequent growth of tea plants and eelworm build up within roots at Kirimetiya Estate, Galaha — (1967) Growth assessments of tea plants made at the end of one year, indicate no significant difference between treatments. A small degree of eelworm build­ up has been observed only within the control plots. This experiment is conti­ nuing. S. Samarajeewa N22 — Levels of N, K, and Ca on nematode reproduction and pathogenicity —in sand culture in pots — (1967) Although variations in growth were observed because of differences in treatments, at the time of assessment no eelworms were recovered from the roots. It is possible that the original inoculum added to sand would have leached out soon after inoculation and that the few that escaped leaching would have been insufficient to colonize the roots successfully. This experiment is being repeated, with modified inoculation techniques. T. Manivasagar N24 — Inoculum levels of Radopholus similis and pathogenicity to tea (TRI 2024) —(1967) No differences in growth were observed between inoculated and unino- culated plants and only a very few eelworms were recovered from the roots of plants that received the highest inoculum. It is possible, that the clone TRI 2024, is resistant to R. similis. This experiment is now being repeated, using TRI 2025, which was subsequently assessed to be susceptible to R. similis. S. Samarajeewa & A. R. M. Hassim 1968 Experiments N25 — The effect of using arboricides on old tea due for uprooting, on the build­ up of eelworm populations in replanted young tea at Great Western Estate, Talawake!e—5 replicates of 3 treatments+control (2 chemicals), in : randomized blocks — (1968) 76 ANNUAL REPORT FOR 1968 Old infested tea roots left in the soil continue to harbour eelworm popula­ tions for more than two years. Although, during the period of rehabilita­ tion under Guatemala grass there is an appreciable reduction in the soil popu­ lation, when the land is planted to tea, the eelworms 'incubating' within the old tea roots become attracted towards the feeder roots of the young plants, As a result, a rapid build up is known to occur. The use of tree-killers was considered to be a possible means of minimizing the hazards of leaving such live infested roots in the soil. In this experiment, the old tea due for uprooting was treated with two arboricides, Shell Weed-killer T at two and three gallons per acre and Prefix wettable powder at 36 lb per acre. All plots treated with Shell Weedkiller T, were found scorched within one month after application, whilst those treated with Prefix, remained unaffected. The post-treatment eelworm counts in the different treatments, are presented in Table 8. TABLE 8 — Post-treatment eelworm count, following treat­ ment with arboricides Treatments Mean eelworm counts Gog n + 1) Arboricide D o s e Shell Weed-killer T 2 gallons 1.428 3 gallons 0 . 4 3 2 Prefix 31b 1.482 Control 1.797 L S D (P = 0 .05 ) 0 . 7 6 4 OP = 0 .01 ) 1.053 A highly significant reduction in eelworm numbers in the soil was ob­ served only in the plots treated with Weedkiller T, at the rate of three gallons per acre. The ten plots treated with this weedkiller, were all uprooted and planted with Guatemala grass. At the end of one year, these plots will be replanted with tea. Of the remaining ten plots, the five plots treated with Prefix that continued to remain unaffected, will be uprooted, fumigated and replanted with tea, while the remaining five plots will continue to be control plots and will be replanted with tea, without any treatments. Growth assess­ ments of tea plants and eelworm build-up within the roots, will be made at regular intervals. S. Samarajeewa N26 — Arboricides on old tea due for uprooting, on the build-up of eelworm populations in replanted young tea at Galkandewatte Estate, Talawa- kele—4 replicates of 3 treatments + control—in randomized blocks — (1968) This experiment is similar to N25, except that the Weedkiller T was applied at three and six gallons per acre and instead of Prefix, Hyvar X was used at four lb per acre. Three months after treatment, the plots were uprooted and planted with Guatemala grass. The experiment is continuing. • S. Samarajeewa N27 — So/7 temperature on the build-up and pathogenicity of P. loosi in tea — 3 treatments of 9 assessments each using 4 replicates at each assess­ ment—(1968) The plants are being grown in a constant environment growth cham­ ber, maintained at the requisite temperature. Assessments are being carried out at three different temperatures, viz 82.5, 70.0 and 52.5°F. The ex­ periment is continuing. ., T. Manivasagar ANNUAL REPORT FOR 1968 77 N28 — Dose of methyl bromide required for fumigating nursery soil—3 repli­ cates of 4 treatments + control in randomized blocks —: (1968) Polythene sleeves filled with heavily-infested soil, were stacked in beds measuring 40 ft x 5 ft, and fumigated with methyl bromide at 1,2 and 4 lb per 200 sq. ft. Growth assessments and eelworm counts are to be made at the end of one year. This experiment is continuing. S. Samarajeewa & A R. M . Hassim N29 — Varietal susceptibility of potatoes to P. loosi—5 replicates of 5 varie­ ties + tea (TRI 2024 — control) in randomized blocks — (1968) Earlier findings (Sivapalan 1968a), have shown that potatoes serve as a useful trap crop to reduce potential dangers of eelworm damage to young tea clearings. In order to test the efficacy of the different varieties of potatoes as trap crops for. the meadow eelworm, five varieties of potato, viz, Arka, Pamir, Cosima, Wanda and Condea, were tested by establishing the tubers of the respective varieties in soils heavily infested with P. loosi. Tuber weights and eelworm counts in roots were assessed at the end of three months. The results are presented in Table 9. TABLE 9 — Potato yields and eelworm build up in roots Mean tuber weights (g) Mean eelworm count (log) Condea 1 1 9 . 2 1 .38 Wanda 1 1 0 . 4 2 . 1 0 Pamir 100 .9 2 . 2 9 Cosima 8 6 . 3 2 . 5 3 Arka 119 .4 2 .61 Tea — 2 . 0 3 L S D ( P = 0 .05) 3 0 . 4 . 0 . 7 0 (NS) The results given in Table 9 indicate that although there were no signi­ ficant differences between varieties in respect of tuber weights; the variety Arka was found to be the most susceptible and Condea the least susceptible to P. loosi. As a source of removing eelworm colonies from infested lands, the variety Arka appears, therefore, to be the most suited, for planting in uprooted tea clearings. S. Samarajeewa, T. Manivasagar & P. A . John N30 — Fertilizer types and levels on pathogenicity and build-up of populations of P. loosi in tea—2 sources of N, at 4 levels + control — each applied to infested and uninfested plants—each treatment replicated 4 times— (1968) The two sources of nitrogen used in this investigation were urea and sulphate of ammonia. One half the number of pots in each treatment was inoculated with approximately 10,000 eelworms per pot. Growth assessments and eelworm build-up in roots are to be assessed at the end of one year. The experiment is continuing. S. Samarajeewa & P. A . John 78 ANNUAL REPORT FOR 1968 N31 — Field performance and tolerance of clones to the Root-Knot Nematode, Meloidogyne brevicauda at Kabaragalla Estate, Elamulla—4 replicates of 6 clones in compact randomized blocks in 2 sets, one fumigated and the other unfumigated — (1968) The test clones include DT 1, TC 9, K 145, TRI 2024, TRI 2025 and TRI 2142. These clones are being tested in soils heavily infested with the Root- Knot Nematode, M. brevicauda. One set of plots was fumigated with methyl bromide at 1 lb p^r 200 sq. ft. Build-up of root-knot nematode populations is to be assessed periodically. S. Samarajeewa N32 — Sampling time on population levels of 3 species of parasitic nematodes in tea at 8 widely-spaced locations — (1968) The three species of parasitic nematodes under investigation are P. loosi, Pratylenchus curvitatus and Helicotylenchus erithrinae. The different test locations include St Coombs; Craighead Estate, Nawalapitiya; Kirimetiya Estate, Galaha; Mooloya Estate, Hewaheta; Park Estate, Kandapola; Lean- gahawela Estate, Bandarawela; Kew Estate, Bogawantalawa and Derryclare Estate, Kotagala. Fortnightly samples are being collected, from these locations and population counts of the above species of nematodes are being estimated. Records of rainfall, soil moisture and soil temperature are being taken at each sampling time in the different locations. This investigation is to be carried over a period of one year. S. Samarajeewa & T. Manivasagar Publications SIVAPALAN, P. (1968a). Potato cultivation and Root-Lesion Nematode of tea. Tea Q. 39, 4-5. SIVAPALAN, P. (1968b). Association of Radopholus similis with decline in young tea fields. Plant Dis. Reptr. 52, 528. REPORT OF THE ENTOMOLOGY DIVISION Entomologist — W. Danthanarayana, BSc, PhD, DIC General Mr. H. B. Herath left the service of the Institute on 31st May ; Mr K. D. Bandularatne assumed duties on 1st August. Dr W. Danthanarayana served on the Standing Committee on Agro-chemicals of the Ministry of Agriculture and Food, and also on the Subpanel for Agrochemicals and Fertilizer of the Industrial Development Board. Laboratory Investigations /, Control of the Ambrosia fungus (Monacrosporium ambrosiiim) A systemic fungicide, Du Pont 1991, was evaluated for its ability to pre­ vent the growth of the ambrosia fungus cultured in Petri dishes. The fungi­ cide was tested at concentrations of 0.25, 0.5, 1.0, 1.5, 2, 5 and 10 ppm in five replicates. All concentrations above 1.5 ppm caused fungistasis of the mycelium and also prevented spqrulation. These effects were greater when the fungicide was incorporated into the agar medium, than when the surface was brushed with the solution of the fungicide. W. Danthanarayana & H. B. Herath A laboratory experiment to supplement the field experiments £ 6 0 and £ 6 2 was carried out to test the fungicide Du Pont 1991. Cut tea branches were placed in bottles containing solutions of the fungicide at concentrations of 0 , 333, 666, 1332 ppm. These concentrations were identical to those used in the field experiments £ 6 0 and £ 6 2 . Live beetles were induced to make galleries in these branches. The branches were dissected later to reveal the galleries. Scrapings from the galleries were inoculated on to culture media on Petri dishes. The Ambrosia fungus was detected in all Petri dishes showing that the fungicide had no systemic effect when applied through cut ends of branches. W. Danthanarayana. & S . N . Fernando Behavioral studies on Shot-hole Borer (Xyleborus fornicatus) A series of experiments were begun to study the behaviour of Shot-hole Borer in relation to gallery construction. The results show that the beetles prefer nodes to internodes for gallery construction. The experiments are being continued. S. N . Fernando Biological Control Project on Shot-hole Borer In 1967, the Institute gave a grant to the Commonwealth Institute of Biological Control (CIBC) to look into the possibility of the biological control of Shot-hole Borer. Work on these lines has since been carried out at various stations of the CIBC, situated in different parts of the world, in order to obtain possible parasites, predators or disease that could be introduced into Ceylon. A chalcidoid parasite known as Perniphora robusta was obtained from, the wood-boring beetle Xyleterus (Trypodendroh) Meatus in West Germany. Perniphora appears to be the principal parasite of bark beetles in Europe boring 79 80 ANNUAL REPORT FOR 1968 the wood of coniferous and deciduous trees. It is known to be a primary parasite of beetle larvae.- In May 1968, a test shipment of 150 adults of Pemiphora were received from the European station of the CIBC. Many of the parasites were dead in transit, but those alive were released at Carolina Group, Watawala. More consignments of the parasite are expected in 1969. Biology of the Red Spider Mite (Oligonychus coffeae) Preliminary studies on the life history are being observed on mites bred on rooted clonal cuttings maintained in nutrient culture solutions. Adult female mites were placed on each mother leaf and then removed after an egg was been laid. In the laboratory, the incubation period of the egg was nine days. The eggs were found firmly attached on to the upper surface of the leaf. They are spherical, but flattened on their lower surface and have an average diameter of 0.14 mm. The studies are continuing. A. Kathiravetpillai Field Experiments and Trials The following experiments have been concluded and the results published: E25, E29-E31, E47, E48, E52, E53, XE1-XE8 (see Report for 1967). E28, E32, E34, E35, E41, E43-E46 (see Danthaharayana, Fernando & Shanmugam 1968) Shot-hole Borer (Xyleborus fornicatus) E33 — Aldrin, dieldrin and heptachlor for shot-hole borer control in new clearings at Carolina Group, Watawala — (1966) : The data for the first year after treatment have been statistically analysed and published (Danthanarayana, Fernando & Shanmugam 1968). The results .up to this time showed that all treated plots gave significantly lower numbers of shot-hole borer than the untreated plots. Heptachlor at 1.7 lb (six pints 23% EC) and dieldrin at 1.5 lb (six pints 20% EC) gave the best •results. There was, however, no significant difference between their efficacy. Aldrin at 1.5 lb (six pints 20% EC) was the next best followed by dieldrin at 0.5 lb and heptachlor at 0.6 lb per acre. The borer population in all plots other than those treated with 1.5 lb dieldrin increased at the end of the first year. The heptachlor treatments were,,therefore, repeated at 13 months after the first application and the results indicate that annual applications of hepta­ chlor at 1.7 lb per acre provide highly effective borer control. The experi­ ment is in progress. E42 — Azinphos-methyl, Bordeaux Mixture, azinphos-methyl + Bordeaux Mixture, ethylene dibramide, fenthion, endrin and DDT for shot-hole borer control at Downside Estate, Welimada — (1967) The results at the end of 20 months after treatment are presented in Table 1. The statistical analysis is based on results upto 16 months after treatment only, and shows that 1.25 lb endrin and 1.7 lb heptachlor gave significant reductions in shot-hole borer numbers. None of the other treatments was as effective. Azinphos-methyl and DDT gave good results upto eight months after spraying. There was no significant difference between the efficacy of endrin and that of heptachlor. Sampling carried out at the 18th arid 20th months after treatment shows that heptachlor is slightly superior-to endrin at these months indicating that heptachlor is more persistent than endrin. TABLE 1 — Post-treatment counts of all live stages of Shot-hole Borer, in Experiment E 4 2 Treatment D o s e (lb ai per acre) N o . per 200 sample units (months after treatment given in parantheses) (2) (4) (6) (8) (10) (12) (14) (16) (18) (20) Azinphos-methyl 1 .0 1 8 50 34 181 82 84 202 117 556 Bordeaux Mixture 7 . 5 12 9 126 120 171 77 127 144 169 470 Azinphos-methyl + Bordeaux Mixture 1 . 0 + . 7 . 5 18 2 26 121 148 120 151 215 143 623 Heptachlor 1.7 0 0 16 10 33 23 73 89 95 250 Methiocarb 1.9 1 23 84 104 94 104 . 133 143 162 450 Ethylene dibromide 1 .2 0 0 56 120 .176 ; 78 : 89 124 71 356 Fehthion 1:5 1 17 4 6 . 113 44 199 130 17 185 435 Endrin ! - 2 0 7 1 36 48 3 ."•21 ' 38 113 423 D D T 2.7: ' 0 1 53 9 101 108 135 127 121 653 Untreated control 1 19 . 4 4 113 128 142 85 118 114 508 L S D (/» = 0 . 0 5 ) M e a n n o . per 50 units (as log ( n + 1 ) ) 0 . 8 4 0 . 9 6 1.01 0 . 4 0 * 0 . 8 9 0 . 9 3 0 . 9 3 6 .39* 0 . 7 8 0 . 9 0 0 . 2 4 5 C > '3 OO Significantly different from the untreated at P < 0 . 0 5 Analysis o f variance carried out o n data u p t o 16th m o n t h after treatment only 82 ANNUAL REPORT FOR 1968 1968 Experiments E59 — Heptachlor post-prune, heptachlor mid-cycle, heptachlor + Estab, hep- tachlor + Lovo, heptachlor-impregnated jute, endrin, endrin + Estab, endrin + Lovo, endrin-impregnated jute, endosulphan and dieldrin for shot-hole borer control at Ury Group, Passara—4 replicates of 11 treat­ ments + control in randomized blocks — (1968) Each plot is l/20th acre in extent. The spraying was done with knapsack sprayers with a spray volume of 80 gallons of water per acre. The main object of this experiment is to determine whether the persistence of heptachlor and endrin can be increased by additive stickers. Mid-cycle and post-prune applications of heptachlor and heptachlor-impregnated and endrin-impregnated pieces of jute are also tested for their effect on borer control. If the latter method is found to be effective, then it will be possible to treat densely-planted VP plants without contaminating the foliage, and also overcome the difficulties involved in mid-cycle spraying which is not practicable in dense stands of VP tea. Two assessments of the borer population were made during the year. The experiment is continuing. W. Danthanarayana & A . Kathiravetpillai E60 — Heptachlor, heptachlor + Plyac, heptachlor-impregnated jute, endrin, endrin + Plyac, endrin-impregnated jute, DDT, DDT + Plyac, BHC, BHC + Lovo, fenthion, fenthion + Lovo and Du Pont 1991 for shot- hole borer control at Kataboola Estate, Kotmale—3 replicates of 15 treatments + control in randomized blocks — (1968) This experiment is similar to E59. Each plot is l/20th acre in extent. The spraying was done with knapsack sprayers, with a spray volume of 80 gallons of water per acre. The plots were sprayed at the end of one year from prune. Du Pont 1991 is a new systemic fungicide and is tested against the Ambrosia fungus of Shot-hole Borer. Two assessments of the borer population were made during the year. The experiment is continuing. E61 — DDT at 3 levels, DDT + Plyac, endrin at 3 levels, endrin + Plyac, heptachlor, heptachlor + Plyac and dieldrin for shot-hole borer control at Kataboola Estate, Kotmale—4 replicates of 11 treatments + control in randomized blocks — (1968) The plot size is l/20th acre. The spraying was carried out with knapsack sprayers, with a spray volume of 80 gallons of water per acre. All treatments were given immediately after pruning. The experiment is in progress and no assessments have been made yet. E62 — Three levels of Du Pont 1991, fenitrothion.fenitrothion + Plyac, endosul­ phan, endosulphan + Plyac, /f-14503, dioxathion, UC 21149 (Temic 10G) and Du Pont 1179 (Lannate) for shot-hole borer control at Carolina Group, Watawala — 4 replicates of 11 treatments + control in rando­ mized blocks — (1968) Each plot is l/20th acre in extent. The spraying was done with knapsack sprayers with a spray volume of 80 gallons of water per acre. The treatments were carried out at the end of one year from pruning. UC 21149 is a new granular systemic insecticide belonging to the carbamate group and was given as a soil dressing around the plants. • Lannate is a new carbamate insecticide, and dioxathion is an;organophos- phate compound not previously tested. Fenitrothion is known to control shot-hole borer for short periods (Danthanarayana et al. 1968) and is tested with the additive sticker, Plyac. Two assessments of the borer population were made during the year. The experiment is continuing. ANNUAL REPORT FOR 1968 83 E63 —- Endrin, DDT, endrin + DDT, heptachlor, heptachlor + Tenac, dieldrin, chlordane, perthane, methoxychlor and Resitox at two levels for shot- hole borer control at Rothschild Estate, Pussellawa—4 replicates of 11 treatments + control in randomized blocks — (1968) Each plot is l/20th acre in extent. The spraying was done with knapsack sprayers, with a spray volume of 80 gallons of water per acre. The treatments were applied immediately after pruning. Perthane and methoxychlor are organochlorine insecticides, and Resitox is a mixture of endrin and DDT formulated by the Shell Co. The experiment is in progress and no assessments have been made yet. E64— VCS 506, Dowco 179 (Dursban), formothion, Resitox, DDT at 3 levels, endrin at 2 levels and C-10015 for shot-hole borencontrol at Telbedde Estate, Badulla—4 replicates of 11 treatments + control in randomized blocks — (1968) Each plot was l/20th acre in extent. The spraying was done with knap­ sack sprayers with a spray volume of 80 gallons of water per acre. The treat­ ments were given at the and of one year from pruning. VCS 506 is a new insecticide and its chemical composition is not yet disclosed. Dowco 179 (Dursban) is an organophosphate compound. C 10015 is a new insecticide belonging to the carbamate group. Two assessments of the borer population were made during the year. The experiment is continuing. E65 — Heptachlor, endrin, endosulpltan, endosulphan +' Plyac, phenthoate:, phenthoate + Plyac, toxaphene, Torbidan, Toxaphene-DDT, toxaphene + Plyac and Miltox for shot-hole borer control at Meddecombra Estate, Watagoda—4 replicates of 11 treatments + control in randomized blocks — (1968) Each plot is l/20th acre in extent on VP tea planted in 1966. The spraying was done with knapsack sprayers with a spray volume of 80 gallons of water per acre. The spraying was done in November 1968. Phenthoate is a new organophosphate insecticide. Torbidan is a mixture of toxaphene, DDT and parathion formulated by Hercules International Corporation. Miltox is a fungicide containing copper oxychloride and Zineb and is included as a treatment against the ambrosia fungus. One assessment of the borer population has been made so far. The experiment is continuing. E66 — DDT at 3 levels, endrin at 3 levels, endrin-impregnated jute, Resitox, heptachlor, heptachlor-impregnated jute.and dieldrin for shot-hole borer control at Deltotte Group, Galaha—4 replicates of 12 treatments— control in randomized blocks — (1968) Each plot is l/20th acre in extent. The spraying was done with knapsack sprayers with a spray volume of 80 gallons of water per acre. The applications of the insecticide were made as post-prune sprays. No assessment of borer control has been made yet. The experiment is continuing. W. Danthanarayana, C. Shanmugam & S. N. Fernando Mites E21 —- Mites, shade and fertilizer on yield at Downside Estate, Welimada — (1965) The experiment began in January 1965 was concluded in September 1968. Definite conclusions can be made only after statistical analysis which has not yet been carried out. . v 84 ANNUAL REPORT FOR 1968 E49 — Purple mite attacks on yield and the effects of shade and fertilizer appli­ cations on purple mite numbers at Liddesdale Group, Halgranoya — (1967) The results for 22 months available up to the end of 1968 show that there is a definite increase in yield in the plots protected from mites with applications of Kelthane. Treated plots consistently showed lower numbers of Purple, Scarlet and Red Spider Mites. The results also indicate that purple mite numbers are higher in the unshaded plots. The Red Spider Mite seems to thrive under shaded conditions. The scarlet mite populations were very low and the differences are not clear. The experiment is in progress. ESO — Purple mite on yield at Diyanilla Division, Liddesdale Group, Halgran­ oya — (1967) The experiment has been in progress for 17 months. The mite popula­ tions have not been very heavy during this period. Sampling for mites was carried out at monthly intervals. There were smaller numbers of mites in the plots treated with Kelthane. A slight yield increase was recorded in the plots where the mites were controlled. The experiment is continuing. E51 — Red Spider Mite on yield at Dambawinna Division, Welimada group, Welimada — (1967) As a result of the very severe drought conditions that prevailed in 1968, a large number of tea bushes died in all plots. It was, therefore, decided to discontinue this experiment. 1968 Experiments E67 — Oxythioquinox at 3 levels, dicofol at 3 levels, dicofol + tetradifon at 2 levels, tetradifon at 2 levels, dinobuton and Dowco 213 (Plictran) for purple, scarlet and red spider mite control at Glenanore Estate, Haputale —4 replicates of 11 treatments + control in randomized blocks — (1968) The main object of this experiment is to evaluate oxythioquinox (Mores- tan) for mite control and determine the minimum dose required. In experi­ ment E48 this acaricide gave very good control of Red Spider and Scarlet Mites. Dinobuton (Acrex) and Plictran are two new acaricides. Each plot is l/20th acre in extent. Spraying was done with knapsack sprayers with a spray volume of 60 gallons of water per acre. One pre-treatment assess­ ment and eight post-treatment assessments of the mite numbers have been made so far. The results of only six post-treatment counts of Red Spider and Scarlet Mites have been statistically analysed, and are presented in Tables 2 to 5. Results of this experiment show that all treatments other than those of tetradifon (Tedion) controlled both active stages and eggs of Red Spider and Scarlet Mites. Dicofol (Kelthane) at the higher rate of 0.26 lb (10 fl. oz) per acre was more effective than the lower dose of 0.13 lb (5 fl. oz) per acre. Oxythioquinox (Morestan) gave extremely good and consistent control of all TABLE 2 — Control of the active stages of the Red Spider Mite with acaricides (Experiment E67) Rate > ai per acre) Pre-treatment count N o . o f mites per 100 leaves Post-treatment counts (Weeks after treatment given in parentheses) (1) (2) (3) (4) (5) (6) 0 . 1 1 792 538 144* 8* 9* 16* 0* 0 . 2 2 942 4 9 0 198* 7* 14* 14* 06* 0 . 3 3 966 364 194* 5* 11* 2 1 * 0 4 * 0 . 1 3 868 802 248* 4 4 * 102 142 87* 0 . 2 6 810 594 340 8* 4 3 * 30* 09* 0 . 1 3 + 0 . 0 2 5 540 676 446 38* 104 4 6 * 27* 0 . 0 7 + 0 . 0 1 3 480 540 286 3 1 * 97 38* 28* 0 . 0 2 5 964 702 4 0 0 37* 45* 3 1 * 34* 0 . 0 5 894 740 368 9* 36* 30* 26* 0 . 6 662 368 144* 34* 6 1 * 97* 4 2 * 0 . 2 502 512 11* 7* 2 * 0 6 * 09* 628 770 576 122 172 199 132 NB Analyses o f variance and covariance carried out o n -\/n and V n + 1 transformed values. * Significantfy different fromTthe untreated at P < 0 . 0 5 : Treatment TABLE 3 — Effect of acaricides on the numbers of red spider mite eggs (Experiment E67) '•' '" N o . o f eggs per 100 leaves' Rate (lb ai per acre) Pre-treatment count Post-treatment counts (weeks after treatment g iven in parantheses) • (1) (2) (3) (4) (5) . Oxythioquinox 0 . 1 1 2196 1998 -394* 65* 40* 25* Oxythioquinox 0 . 2 2 2352 2224 •718* 96* 7 1 * 51* Oxythioquinox 0 . 3 3 2588 1128 698* 62* 60* 34* Dicofol 0 . 1 3 1790 3186 682* 272* 384* 266 Dicofol 0 . 2 6 1810 1728 706* 60* 133* 104* Dicofol + tetradifon 0 . 1 3 0 . 0 2 5 1596 1844 1518 152* 319* 81* Dicofol + tetradifon 0 . 0 7 0 . 0 1 3 1410 2014 1088 229* 290* 102* Tetradifon 0 . 0 2 5 2482 3026 1962 564 519 340 Tetradifon 0 . 0 5 2402 2936 1474 298* 448 158* Diriobuton 0 . 6 1 1 6 6 1320 548* 203* * 363* 105* Plictran 0 . 2 1736 1214 130* 76* 72* 28* Untreated control 1682 2230 1892 770 713 578 NB Analysis o f variance was carried out oh Vn transformed values * " Significantly different from the untreated at P < 0 . 0 5 TABLE 4 — Control of the active stages of the Scarlet Mite with acaricides {Experiment E67) N o . o f mites per 100 leaves Treatment Rate Pre-treatment Post-treatment counts (lb ai per acre) count (weeks after treatment in parantheses) (1) (2) (3) (4) (5) Oxythioquinox 0 .11 2128 634 218* 16 6 2 7 1 * Oxythioquinox 0 . 2 2 3428 182 80* 05* 10* 16* Oxythioquinox 0 . 3 3 1046 916 52* 7* 15* 3 1 * Dicofo l 0 . 1 3 1130 4 3 4 84* 17 31 36* Dicofol 0 . 2 6 1762 298 76* 0 5 * 16 12* Dicofol + tetradifon 0 . 1 3 0 . 0 2 5 632 836 56* 11* 2 2 4 0 * Dicofol + tetradifon 0 . 0 7 0 . 0 1 3 330 2058 46* 16 2 0 27* Tetradifon 0 . 0 2 5 1408 842 364 76 253 311 Tetradifon 0 . 0 5 1046 318 686 31 136 168 D i n o b u t o n 0 . 6 390 258 38* 0 6 * 10* 2 4 * Plictran 0 . 2 374 46 0 4 * 07* 06* 0 8 * Untreated Control 662 842 422 47 88 4 5 3 - NB Analysis o f variance and covariance carried out. o n V n + 1 transformed values * Significantly different from the untreated at P < 0 . 0 5 TABLE 5 — Effect of acaricides Treatment Rate Pre-treatment (lb ai per acre) count Oxythioquinox 0 . 1 1 1694 Oxythioquinox 0 . 2 2 2950 Oxythioquinox 0 . 3 3 1092 Dicofo i 0 . 1 3 1282 Dicofo l 0 . 2 6 1648 Dicofo i + 0 . 1 3 + 562 tetradifon 0 . 0 2 5 Dicofo i + 0 . 0 7 + 312 tetradifon 0 . 0 1 3 Tetradifon 0 . 0 2 5 1520 Tetradifon 0 . 0 5 974 D i n o b u t o n 0 . 6 552 Plictran 0 . 2 308 Untreated Control 604 the number of scarlet mite eggs (Experiment E67) N o . o f eggs per 100 leaves Post-treatment counts (weeks after treatment in parantheses) (1) (2) (3) (4) (5) (6) 532 310* 88* 66 37* 35* 332 222* 2 1 * 26* 16* 19* 1442 68* 14* 26? 17* 06* 400 134* 40* 22* 2 1 * 54 284 122* 31* 08* 24* 12* 700 108* 71* 47 2 1 * 28* 1696 96* 73* 25* 17* 52 730 308* 396 353 143 147 296 688 199 164 108 53 290 100* 24* 12* 14* 2 1 * 123 23* 2 3 * 11* 17* 06* 800 538 345 125 352 152 NB Analysis o f variance and covariance carried out o n \/a+1 values, o n corrected data. * Significantly different from the untreated at P < 0 . 0 5 ANNUAL REPORT FOR 1968 89. stages of both species of mites, confirming the results of experiment E48.! These results provide sufficient evidence to recommend Morestan for red spider and scarlet mite control as an alternative to Kelthane. Morestan may be used at the rate of 10 to 14 oz per acre in a suitable quantity of water in knapsack sprayers or mistblowers. Recommendations based on these new findings will be released in 1969. Plictran and dinobuton (Acrex) proved themselves to be effective acaricides. These compounds need further investigation in this respect. E68 — Oxythioquinox at 3 levels, dicofol at 3 levels, dinobuton and prothoate for purple, scarlet and red spider mite control at Welimada Group, Weli­ mada—4 replicates of 7 treatments + control in randomized blocks — (1968) • i The layout of this experiment is similar to that of E67. The results of this experiment are similar to those of E67, but they have not yet been statisti­ cally analysed. E69 — Oxythioquinox at 3 levels, dicofol at 2 levels, dinobuton and Dowco 213 (Plictran) for purple, scarlet and red spider mite control at Gonamotawa Estate, Haputale—4 replicates of 7 treatments + control in rando­ mized blocks — (1968) The layout of this experiment is similar to that of E67. The results of this experiment are similar to those of E67 and E68, but have not yet been statisti­ cally analysed. W. Danthanarayana & D . J. W. Ranaweera Tea Tortrix (Homona coffearia) E56 — The biology and population dynamics of Tea Tortrix — (1967) Data for one complete year on the build up of the tortrix population after dieldrin application are now completed. In addition to Macrocentrus homohae, the external larval parasite (Phytodiaetus capuae) and the egg parasite Tricho- gamma sp. have been obtained. Two pathogenic organisms, a bacterium and a fungus have been isolated from tortrix larvae and are now being cultured for laboratory-controlled tests. Data for the first year are being analysed. The experiment is continuing. W. Danthanarayana, A. Kathiravetpillai &. K. D . Bandularatne 1968 Experiments E57 — Azinphos-methyl, fenitrothion, methyl-parathion, SD 8447 (Gardona) Du Pont 1179 (Lannate), GS 13005 (Supracide), DDT, aminocarb -tj tri- chlorphon and aminocarb for tea tortrix control—4 replicates of 11 treatment + control in randomized blocks — (1968) This experiment has been concluded and the results published (Dantha­ narayana & Ranaweera 1968). 90 ANNUAL REPORT FOR 1968 E58 — DDT, methyl parathion, DDT + methyl parathion, aminocarb, du Pont 1179 (Larmate), SD 8447 (Gardona), fenitrothion, /M4503, dioxathion, SD 9129 (Azodrin) and phosalone for tea tortrix control—4 replicates of 11 treatments + control in randomized blocks — (1968) This experiment has been concluded and the results published (Dantha- narayana & Ranaweera (1968). E70 — Loss of crop caused by Tea Tortrix—12 replicates of 2 treatments in randomized blocks — (1968) Each block consist of four plots l/20th acre in extent each. Two plots were treated with DDT for tortrix control and the other two plots were left untreated for the tortrix population to build up. Pre-assessment of yield of all plots was carried out for one year in 1968 at the end of which a round of dieldrin was applied onto specific plots to induce tortrix development. The experiment is in progress. W. Danthanarayana & C . Shanmugam Termites E54 — Dieldrin, aldrin, heptachlor, chlordane, chlordane + aldrin, chlordane + heptachlor, dimethoate, phosphamidon and dichlorvos for the control of the Up-Country Live Wood Termite at Moray Group, Maskeliya — (1967) The insecticides were sprayed on the frame and on the soil surrounding the tea bushes. None of the treatments gave a satisfactory degree of control. The treatments were then modified by applying the insecticide solutions through open galleries into the termite nests. This was done by cutting the infested branch, exposing the gallery and injecting the insecticide through the open gallery. The swirl plate of the nozzle was removed, the lance of the knapsack sprayer was placed at the cut end of the gallery and a squirt of insecticide was then forced in. This method was found to work well with all insecticides, provided the liquid penetrated most galleries. This is not an entirely satis­ factory method of control. The experiment is concluded. D . J. W. Ranaweera E55 — Dieldrin, aldrin, heptachlor, chlordane, chlordane + aldrin, chlordane + heptachlor, dimethoate, phosphamidon and dichlorvos for the control of the Low-Country Live Wood Termite at Galbode Estate, Ratnapura — (1967) None of the treatments was found to be effective. The experiment is concluded. 1968 Experiments E71 — Dieldrin, aldrin, heptachlor, chlordane, UC-21149 (Temik 10G), dime­ thoate, Dowco 179 (Dursban), phenthoate, prothoate, endrin and DDT + endrin for the control of the Low-Country Live Wood Termite at Galbode Estate, Ratnapura—4 replicates of 11 treatments + control in randomized blocks — (1968) None of the treatments were found to be appreciably effective. A few bushes treated with dieldrin, aldrin, chlordane or heptachlor showed signs of termite control. W. Danthanarayana & A. Kathiravetpillai ANNUAL REPORT FOR 1968 91 Lectures and Symposia Lectures DANTHANARAYANA, W.—"Some problems of tea production in the hill country" at a symposium on "Some aspects of agricultural development in the hill country of Ceylon" conducted by the Ceylon Association for the Advancement of Science at Peradeniya in August. DANTHANARAYANA, W.—"Shot-hole borer control with heptachlor" to the Kelani Valley Planters' Association at Talduwa in September. DANTHANARAYANA, W.—"Shot-hole borer control" at a symposium organized by Carson Cumberbatch & Co. Ltd., at Colombo in September. DANTHANARAYANA, W.—"Shot-hole Borer and side-effect problems" to the Pussellawa Planters' Association at Pussellawa in December. DANTHANARAYANA, W.—"Application of integrated control concept to the shot-hole borer problem of tea" at the 24th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in December. DANTHANARAYANA, W . & WICKREMASINGHE, N.*—"Insecticides and problems arising from chemical pest control" at a symposium on "Crop Pro­ tection" at the 24th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in December. *Central Agriculture Research Institute, Peradeniya. Symposium Dr W . Danthanarayana participated in a symposium on "Drought" organized by the Institute for the Uva Planters' Association at Badulla in November. Publications DANTHANARAYANA, W . (1968a). The distribution and host range of the Shot- hole Borer (Xyleborus fornicatus Eichh.). Tea Q. 3 9 , 61-69. DANTHANARAYANA, W . (1968b) Shot-hole borer control : Recommendations— 1969. Tea Q. 3 9 , 115-118. DANTHANARAYANA, W . & RANAWEERA, D . J. W . (1968). The chemical con­ trol of Tea Tortrix (Homona coffearia Nietner). Tea Q. 3 9 , 50-60. DANTHANARAYANA, W . , FERNANDO, S. N. & SHANMUGAM, C. (1968). Recent developments in research on shot-hole borer control. Tea Q. 3 9 , 94-114. Acknowledgements The co-operation of the Superintendents and Assistants of estates on which experiments were carried out is gratefully acknowledged. The help of the Statistician and his Assistant in the design of the experiments and the analysis of the results is acknowledged. Our thanks are also due to all firms which provided free samples of pesticides for experimental purposes. 92 ANNUAL REPORT FOR 1968 Glossary of insecticides, acaricides and fungicides used in field experiments Active constituent Trade name Owner Agent Aldrin Aldrex-20 Shell Shell Aminocarb Metacil 5 0 % W P Bayer Shell Azinphos-methyl Gusathion 2 0 % EC Bayer Hayleys Chlordane Intox-8 ( 7 0 % EC) Sandoz Baurs C-10015 C-10015, 5 0 W P Ciba Baurs Dichlorvos V a p o n a 4 8 % E C Shell Shell DicMorvos N o g o s 1 0 0 % E C Ciba Baurs Dicofoi Kelthane M F 4 2 % R h o m & Hass Mackwoods D D T Deenol Baurs Baurs D D T A r k o t i n e D - 1 8 Shell Shell DDT-endr in Resitox Shell Shell Dieldrin Dieldrex-20 Shell Shell Dimethoate Rogor-40 ( 3 0 % EC) Fisons Fisons Dimethoate Rox ion E C 40 Cela Ceypag Dinobuton Acrex 30 E C Murphy Dioxathion Delnav 8 0 % E C Hercules — D o w c o 179 Dursban 4 E D o w Harrison & Crosfield D o w c o 213 Plictran 5 0 W P D o w Harrison & Crosfield D u P o n t 1179 L a n n a t e 9 0 % D u Pont Shell D u Pont 1991 D u Pont 1991-50% D u Pont Shell Endosulphan Thiodan 3 5 % EC Hoechst Mackwoods Endrin Endrex-20 Shell Shell Ethylene dibromide Dpwfume W-85 D o w Harrison & Crosfield Fenitrothion Folithion E C 50 Bayer Hayleys Fenitrothion Sumithion E C 50 Sumitomo Shell Fenthion Labaycid 5 0 % E C Bayer Hayleys Fenthion Baytex 4 0 % W P Bayer Hayleys Formothion A n t h i o 2 5 % E C Sandoz Baurs G S 13005 Supracide Geigy Fisons Heptachlor Heptachlor 2E Velsicol Baurs Heptachlor Heptamul 20 & 40 E C — Mackwoods H-14503 H-14503-EC 8 0 Hercules ^ — Methoxychlor Marlate 2 - M R D u Pont Shell Methyl-parathion Folidol M-50 Bayer Hayleys Oxythioquinox M o r s t a n 2 5 % E C Bayer Hayleys Perthane Perthane 4 0 % E C R h o m & Hass Mackwoods , Shell Phenthoate Cidial 5 0 % E C Montecatini C. E . Peries & Co . Phosalone Zolone 3 5 % E C Rhone-Poulenc Baurs Phosphamidon Dimecron 5 0 % E C Ciba Baurs Prothoate F a c 4 0 Montecatini C. E . Peries & Co . S D 8 4 4 7 Gardona 50 % EC Shell Shell S D 9129 Azodrin 5 0 % E C Shell Shell Tetradifon Tedion V-18 Duphar Mackwoods Toxaphene Toxaphene 6 0 % E C Hercules — T o x a p h e n e + D D T T o x a p h e n e - D D T 4:2 Hercules — T o x a p h e n e + D D T + p a r a t h i o n i Torbidan 4:2:1 Hercules — Trichlorphon Dipterex SP 80 Bayer Hayleys UC-21149 Temik 10G U n i o n Carbide Mackwoods VCS-506 VCS-506 Velsicol Baurs Z i n e b + c o p p e r oxychloride . Miltox Sandoz Baurs REPORT OF THE BIOCHEMISTRY DIVISION Biochemist — R. L. Wickremasinghe, BSc, PhD, FRIC General Mr W. A, B. de Silva, Technical Assistant, joined the staff of the Division on 1st August, and filled the vacancy created by the resignation of Mr M. H. Rodrtgo on 26th December 1967. Dr. R. R. Selvendran returned to Ceylon on 23rd October after three years of post-graduate, and one year of post-doc­ toral work in the United Kingdom. His doctoral thesis dealt with "The metabolism of phosphate esters and nucleotides in mature strawberry leaves", and his post-doctoral work (as Broodbank Fellow) was on "The metabolism of phosphate compounds in tea leaves". Mr K. Sivapalan returned to Ceylon on 15th October from New Delhi after a two-year period of post-graduate work at the Indian Agricultural Research Institute, where he was awarded, a Master's Degree in Science on his thesis entitled "Nucleic acid metabolism in two varieties of wheat in relation to nitrogen fertilization". Dr A. S. L. Tiri- manna resigned from the Institute on 31st October. A part of the staff and equipment of the Biochemistry Division was moved to the Low-Country Station, Ratnapura, during May. I Laboratory Investigations Chemical analyses of different types of tea Chemical analyses for polyphenols and amino-acids were carried out on . samples of black, green and instant teas. Some of the results, summarized in Table 1, indicate the wide dissimilarities in the chemical constituents. The following points are noteworthy : •• • • ! . 1 — Liquors of low-grown black tea have a higher level of polyphenols than those of black tea manufactured from high grown leaf. I 2 — Black tea has a lower level of free polyphenols and a higher level of bound polyhenols than green tea. This is to be expected be­ cause the first stage of green tea manufacture is the destruction of the enzyme responsible for the conversion (oxidation) of poly­ phenols to a form which is easily bound. 3 — The finest grade of Japanese green tea has a low level of poly­ phenols and a high level of amino acids. Green tea made from clonal leaf grown at St Joachim had a much higher level of poly­ phenols and a lower level of amino acids. Samples of this clonal green tea were sent through Consolexpo to Japan, where the tas­ ters reported the samples as being 'too bitter' for the Japanese palate. •• . . .i 4 — The values given in Table 1 for instant tea are a rough average of the analyses of ten commercial samples, and are given only for purposes of comparison. Although the polyphenol content of instant tea was similar to that of the liquor of a St Coombs tea, the qualitative paper chromatographic picture showed that the instant teas were lacking in several desirable components. : ! i 93 94 ANNUAL REPORT FOR 1968 TABLE 1 — Analyses of different types of tea Polyphenols Amino acids Black tea, St C o o m b s 130 20 Black tea, St Joachim 180 20 Instant tea 130 15 Free Bound Black tea (average value) 60 130 20 Green tea (Japanese, high grade) 143 36 48 Green tea (Japanese, average) 168 61 22 Green tea (St Joachim) Clone 162 400 13 17 Clone 165 510 31 16 Clone 19 399 26 15 Green tea (Chinese) 238 21 17 U. L. L. de Silva & W. A . B. de Silva Proteins of tea Quantitative analyses for protein were made of aqueous extracts of tea flush, freed of polyphenols by treatment with Polyclar. These analyses indi­ cated that some of the polyphenols (chlorogenic acids, p-coumarylquinic acids and theogallin), were not, in fact, removed by the polyclar treatment and interfered with the quantitative determinations of protein. Accordingly, the aqueous extracts of protein were separated by paper electrophoresis, after which the pure protein was eluted from the paper and estimated. The results obtained so far indicate that there is a slight drop in protein levels of flush during withering, and a very marked decrease during fermentation. The aqueous extracts of protein will, however, contain only a part of the protein fraction (albumin and perhaps, globulins), and attempts are now in progress for the estimation of other protein fractions (prolamines and glutelins). U . L. L. de Silva Analyses of different parts of the tea bush Analyses have been carried out for the polyphenol and amino acid con­ tents of leaves of different ages, large roots, small roots and tea bark. The results, summarized in Table 2, show a progressive decrease with age in the amount of polyphenol and amino acids present in leaves, and also that St Joachim flush has a higher level of polyphenols than St Coombs flush. Tea bark contained an appreciable amount of polyphenols, but chromatographic analyses showed that the picture was different to that of leaves, and suggested that extracts of tea bark would be suitable for the tanning of animal hides in leather production. The roots had a comparatively low level of polyphenols, and among the amino acids, theanine was predominant. ANNUAL REPORT FOR 1968 TABLE 2—Analyses of different parts of the tea bush 95 Clone 2025 Bud lst . leaf 2nd leaf 3rd leaf 5th leaf 7th leaf Tea bark Small roots ( i - 1 m m diameter) Large roots (3 -6 nun diameter) Total polyphenols SJ 885 649 676 598 487 481 300 76 74 S C 288 333 304 222 186 Vanillin reacting polyphenols SJ 355 322 310 309 282 286 212 58 49 SJ S C Amino acids - mi- St Joachim St Coombs B, P. M . Perera, K. P. W. C. Perera & W. A . B. de Silva Studies on flavour i A comparsion was made of the chemical compounds present in the vola­ tile fractions from high-grown (St Coombs) and low-grown (St Joachim) black teas. Separation was effected by gas liquid chromatographic methods. Table 3 gives a list of the compounds indentified, together with a description of the characteristic aroma and the peak area percentage. This percentage is a measure of the relative quantity of the compound present in the volatile fraction. It is seen from Table 3 that many compounds, eg linalool and its derivatives, geraniol and cis-jasmone are present in relatively higher concentrations iri the St Coombs tea samples than in the St Joachim sample. This relatively high level is mainly due to the large quantity of compounds of low retention Jime (including sulphides and mercaptans, not identified in the present study), which occur in St Joachim teas. It is possible that the occurrence of these compounds in low-grown tea may overwhelm and nullify the effect ofjany desirable compounds which are present in these teas. These gas liquid chroma­ tographic studies were carried out together with Professor Tei Yamanishi, who worked at St Coombs for about a month, in her capacity as an Expert Adviser under the auspices of the Asia Productivity Organization. Part of the analyses were carried out at St Coombs and part in her own laboratories, which specialize in flavour research, at Ochonomizu University, Tokyo. A more detailed account of the results of these findings have been reported in The Tea Quarterly (Yamanishi, Wickremasinghe & Perera 1968). Other experiments were attempts to induce flavour by feeding leucine to tea flush, and also by artificially increasing the manganese content of tea flush by spraying manganous sulphate on tea growing in the field. The use of leucine was based on the hypothesis that leucine was a precursor of the com­ pounds responsible for tea flavour (Wickremasinghe 1967), whilst.the possible importance of manganese was indicated by the finding that the manganese TABLE 3 — Comparison of the aroma pattern of high and low grown tea as Peak Retention N o . time (min) Peak assignment A r o m a of effluent 1 2 . 8 iso-Butanal sweet ^ j t . - j y r ^ S ^ ^ 2 3 . 8 n-Butanal 3 4 . 6 iso-Pentanal , 4 5 . 4 U n k n o w n 5 6 . 4 » methional-l ike 6 7 . 7 greenish 7 9 . 8 iso-Butanol (include unknown) cheese-like 8 1 1 . 0 n-Hexanal (n-Butanol) greenish , . 8 ' 1 1 . 8 U n k n o w n sweet & fruity 9 1 3 . 4 1-Penten 3-ol somewhat stimulant 10 1 4 . 2 U n k n o w n sweet & acidic 1 1 . 1 6 . 0 U n k n o w n b lood & metal odour 12 1 7 . 6 iso-Pentanol sweet alcohol ic 13 1 8 . 7 n-Heptanal greenish 2 14 2 0 . 3 trans-2-Hexenal (n-Pentanol) greenish & somewhat cinnamon-l ike 15 2 2 . 3 U n k n o w n metallic, unpleasant odour 16 2 3 . 8 »> amylacetate-like 1 6 ' 2 4 . 2 »» greenish 17 2 6 . 0 cis-2-Pentenol , sweet & fruity 18 2 6 . 8 Octanal (include unknown) acetamide-like 19 2 8 . 5 cis-3-Hexenylacetate pear-like 20 2 9 . 4 n-Hexanol (include unknown) greenish, cinnamaldehyde-l ike 21 3 1 . 3 cis-3-HexenoI grassy, fresh leaf-like St C o o m b s 0 . 7 0 . 5 4 . 4 0 . 9 0 . 4 0 . 1 3 . 8 0 . 2 3 . 1 1 . 0 7 . 7 St Joachim . 3 . 2 2 . 2 8 . 2 trace 0 . 6 1 .6 0 . 9 1 . 0 0 . 4 0 . 4 1 .6 2 . 3 0 . 4 1.5 2 . 2 0 . 1 9 . 4 1 3 . 0 > z z c > r w -a O H •n O TABLE 3 — Comparison of the aroma pattern of high and low grown tea — (Continued) Retention time (min) Peak assignment aroma of effluent St C o o m b s St Joachim 3 2 . 7 trans-2-Hexenol chrysanthemum leaf-like 4 . 2 1 .6 2 4 . 8 trahs-2-OctenoI (cis-5-member) somewhat oily — — 3 6 . 7 Linalool oxide I (cis-5-member) Japanese parsley-like 3 . 2 1 .5 3 9 . 0 Linalool oxide II (trans-5-member) earthy & camphor-l ike 1 5 . 5 4 . 2 4 0 : 6 U n k n o w n — 4 3 . 2 Linalool Lily-of the valley-like 2 9 . 0 7 . 3 4 5 . 3 U n k n o w n cucumber-like trace — 4 7 . 2 3 .5-Octadienone fresh trepang-like trace 0 . 7 4 8 . 6 U n k n o w n earthy & mould- l ike 0 . 2 0 . 1 4 9 . 5 „ rose-like — 5 1 . 0 Phenylacetaldehyde rose-like 4 . 6 3 . 0 5 3 . 4 U n k n o w n sweet aroma 0 . 8 0 . 3 5 6 . 0 » » menthol- l ike 0 . 5 trace 5 7 . 2 Linalool oxide II cucumber-l ike 6 . 9 2 . 8 6 0 . 2 U n k n o w n greenish — — 6 3 . 1 Methylsalicylate (Nerol) winter green oil-l ike 1 .1 0 . 7 6 3 . 8 . Geraniol rose & citrous-like 5 . 2 2 . 4 6 6 : 4 Benzyl alcohol somewhat hay-like 2 . 2 1 . 0 7 0 . 7 Phenylethanol rose-like 3 . 6 9 . 4 7 5 . 0 cis-Jasmone jasmin & hay-like 0 . 3 0 . 2 8 4 . 2 Nerol idol flowery 4 . 1 2 . 6 8 6 . 9 Pyrrylmethylketone stimulant, s m o k y — : — 102 .7 Pyrrol aldehyde bitter, sweet & phenol ic 3 . 9 4 . 3 1 2 7 . 8 Indole ? somewhat flowery 3 . 9 5 . 5 98 ANNUAL REPORT FOR 1968 content of flush rose during the flavoury season (Wickremasinghe, Perera & de Silva, 1969). In both experiments the TRI taster valued the treated teas higher than the controls, although he found no evidence of flavour in the leucine-feeding experiment. The detailed results of the manganese spray experiment are given in Table 4. Here manganous sulphate (0.25% w/v), in aqueous solution was sprayed on clonal tea (DT 1) growing at St Coombs. Spraying was done after each pluck at about weekly intervals, and the flush analysed for manganous manganese and ferric iron, and mini-manufactured, after which the taster • examined the black teas. The results indicated that the spraying of manganese was beneficial, but that excessive levels of manganese resulted in rawness of the liquor, presumably due to the toxic effect of high levels of the metal on the enzymes responsible for fermentation. It is of interest that the spraying of manganese caused changes in the concentrations of ferric iron as well, and this is noteworthy because the ratio of manganous manganese to ferric iron (Mn++/Fe+ ++) , may be a factor of some importance in tea manufacture. The detection of flavour in the treated sample on 25.1.68, doubtful flavour on 1.2.68, and its disappearance thereafter, may indicate an optimal level of M n + + or M n + + / F e + + + for flavour development. It must also be mentioned that the experiment was carried out during flavoury weather conditions at St Coombs. In a separate experiment, manganese contents and M n + + / F e + + + ratios in seven clones were determined at monthly intervals over a period of one year. The clones analysed were TRI 777, DT 1, TK 48, TRI 2024, CH 13, TRI 2142, TRI 2025, TRI 26 and TRI 740, and very marked seasonal and inter-clonal variations were observed to occur. Perhaps the only significant finding was that DT 1 and TRI 777 always had comparatively higher levels of manganese than the other clones. K. P. W. C. Perera & U. L. L. de Silva Microbiology of tea flush The studies of the seasonal changes in the microbial flora of tea flush initiated in 1967, were continued. It was observed at St Coombs, that the microflora showed marked qualitative and quantitative changes throughout the year. In the months preceding the flavoury season, yellow colonies of a xanthomonad, white colonies of a micrococcus and a bacillus, and a black- spored Aspergillus spp. were the predominant micro-organisms. All of these showed a very marked decrease in numbers during the flavoury season, and increased again at the end of the flavoury season. A similar sequence of chan­ ges in the microbial flora occurred in Uva where, however, examinations were carried out only during the period July to September. A very similar picture had been obtained in 1967 and confirmed that climatic conditions affect the microbial microflora on tea flush. B. P. M . Perera Metabolism of phosphate compounds in tea leaves This work was done by Dr R. R. Selvendran during the tenure of his post­ doctoral Broodbank Fellowship at the Low Temperature Research Station, Cambridge. An investigation was undertaken to ascertain the major phosphate esters and nucleotides in tea flush (TRI 777) and the changes which they undergo during tea manufacture. The first stage in this study was the isolation of the acid-soluble phosphate compounds in a trichloroacetic acid extract by two T A B L E 4 — Effect of Manganese spray on clonal (DT 1 ) flush growing at St Coombs F L U S H P L U C K E D B E F O R E A «= Treated S P R A Y I N G O N M n a + ( p p m ) Fe3+(ppm) M n 2 + / F e s + Taster's reports B = Control Treated Control Treated Control Treated Control Colour of infused leaf Infused leaf Colour Strength Quality Flavour 9th January 1968 N o Plucking N o t Analysed — — — — N o Manufacture 18th January 1968 7 7 5 . 9 8 7 4 . 4 3 4 . 5 2 2 . 0 2 2 . 4 9 3 9 . 7 5 A C 8 5 6 8 B C / G 7 5 6 7 - 25th January 1968 8 4 6 . 6 8 3 0 . 0 2 9 . 0 1 5 . 0 2 9 . 1 9 5 5 . 3 3 A C / G 7 4 6 8 2 B C/G 7 4 6 8 - 1st February 1968 1 0 2 0 . 2 7 9 8 . 1 3 7 . 0 4 0 . 0 2 7 . 5 7 1 9 . 9 5 A C/G 7 4 6 8 ? B C/G 7 5 5 8 ? . l o t h February 1968 N o Plucking 1283 .9 805 .1 4 4 : 0 3 0 . 5 2 4 . 2 9 2 6 . 4 0 N o Manufacture 16th February 1968 N o Plucking 1283 .9 9 0 9 . 1 3 0 . 5 2 8 . 5 4 2 . 1 0 3 1 . 8 9 N o Manufacture 23rd February 1968 N o Plucking 1519 .9 7 5 6 . 4 5 0 . 0 3 9 . 0 3 0 . 4 0 1 9 . 3 9 N o Manufacture 28th February 1968 1158 .3 8 9 5 . 3 6 0 . 0 4 9 . 0 1 9 . 3 2 1 8 . 2 7 A C/G 6 4 4 6 R a w B C / G 7 5 6 8 - 14th March 1968 N o t Sprayed 1 7 5 7 . 2 9 9 9 . 4 3 3 . 0 2 2 . 0 5 3 . 2 5 4 5 . 4 3 A G 5 4 5 7 V. green B G 9 7 5 • 7 Green 29th March 1968 N o t Sprayed 1 0 8 2 . 6 8 4 6 . 7 3 8 . 0 2 2 . 5 2 8 . 4 9 3 7 . 6 3 A = Sprayed with manganese sulphate solution in water ( 0 . 2 5 % w/v) M n J * — Manganous manganese B = Unsprayed control F e 3 + — ferric iron C = Coppery C / G = Coppery/Green 100 ANNUAL REPORT FOR 1968 stage chromatography on cellulose columns using organic solvents (Selvendran & Isherwood 1967). The purified extract was fractionated on Dowex-1 for­ mate columns using ammonium formate buffers. Individual phosphate esters and some nucleotides in the purified extract were estimated enzymatically. The following nucleotides were found to be present in appreciable quanti­ ties in fresh flush, ATP, UTP, CTP, ADP, UDP, UMP-5, UMP-3 and UDP- sugars (UDP-glucose). ATP, ADP, (AMP), UDPG, glucose-6-phosphate, fructose-6-phosphate, glucose-1-phosphate, glucose-1, 6, diphosphate and sucrose-6- phosphate in the purified extract were determined enzymatically. Manufacture of tea was accompanied by the following changes : The carbondioxide output decreased markedly; acid-soluble in­ organic phosphate increased, particularly during fermentation and firing; total acid-soluble phosphate increased. Withering caused a significant decrease in the level of nucleoside triphosphates, while nucleoside diphosphates changed little. Min­ cing caused rupture of the cell membranes and considerably altered the respiratory mechanism of the tissue. This was reflec­ ted in the marked increase in the level of nucleoside triphos­ phates. Firing resulted in a decrease in the level of triphosphates and a parallel increase in the level of diphosphates. The most notable change on firing was a ten-fold increase in UMP-3. I Changes in the level of phosphate esters in shoot tips during manu­ facture of black tea were typical of senescing plant tissues. Notably the levels of glucose-6-phosphate, fructose-6-phosphate and glu- cose-l-phosphate were markedly reduced during withering. The changes in these compounds during fermentation and firing were slight. The possible implications of these changes on the quality of the made tea are being investigated. R. R. Selvendran Peroxidases in tea flush Polyclar extracts of tea leaf juice, analysed by starch gel electrophoresis, showed the occurrence of seven bands having peroxidase activity. The bands were visualized by the method based on the oxidation of benzidine in the pre­ sence of hydrogen peroxide. Preliminary experiments indicated that changes occurred in the peroxidases during fermentation. ; A . S. L. Tirimanna Upgrading of St Joachim tea Experiments on the upgrading of St Joachim tea were directed mainly to the adaptation of the process to orthodox manufacture rather thanCTC- Rotorvane methods. These experiments were successful, but more work remains to be done in making the process reproducible. K. P. W. C: Perera ANNUAL REPORT FOR 1968 101 Visits, Lectures and Symposia TIRIMANNA, A. S. L . — "Studies on the flavour of Ceylon teas"— presented at 24th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in December. TIRIMANNA, A. S. L . & RANASINGHE, A. — "The occurrence of peroxidases in the tea leaf' — presented at 24th Annual Sessions of the CAAS at Colombo in December. WICKREMASINGHE, R. L . — "Chemistry of tea manufacture" — Invitation lecture to University undergraduate students — in March. WICKREMASINGHE, R. L . — "Biochemistry and tea manufacture" — address to the Kelani Valley Planters' Association in July. WICKREMASINGHE, R. L . — Participated in the "Symposium on Drought" at Badulla on 29th November. Acknowledgement Grateful thanks are due to Messrs Ranjit Sri Nissanka, C. H. Wick- remesinghe and O. L . de Ktetser, without whose ready and enthusiastic help, the up-grading and other experiments on manufacture could not have been evaluated. Publications SELVENDRAN, R. R. & ISHERWOOD, F. A. (1967). Identification of guanosine derivatives of D-xylose, D-mannose, D-glucose and D-galactose in mature strawberry leaves. Biochem. J. 105, 723-727. WICKREMASINGHE, R. L . (1968). Some observations on tea in Japan. Tea Q. 39, 25-28. WICKREMASINGHE, R. L. , PERERA, B. P. M. & D E SILVA, U. L . L . (1969). Studies on the quality and flavour of tea—A—Observations on the biosynthe­ sis of flavour. Tea Q. 40, 26-30. YAMANISHI, TEI, WICKREMASINGHE, R. L . & PERERA, K. P. W. C. (1968). Studies on the quality and flavour of tea—3—Gas chromatographic analyses of the aroma complex. Tea Q..39, 81-86. Reference •. - WICKREMASINGHE, R. L . (1967). Fact and speculation in the chemistry and biochemistry of tea manufacture. Tea Q. 38, 205-209. REPORT OF THE TECHNOLOGY DIVISION Technologist — D. Kirtisinghe, BSc, PhD, DIC, C Eng, AMIChemE General During the year under review the staff position of the Division continued to deteriorate. The Tea Taster's contract was not renewed when it expired early in the year. Mr N. M. Abdul Gaffar, Research Assistant, proceeded overseas on a Commonwealth Scholarship for training in Biochemical Enginee­ ring at the Universtiy College, London. Mr S. Jayaratnam was appointed Technical Assistant. The Technology Units at Kottawa and Passara were closed down as a measure of economy and the officers of the Technology Divi­ sions at these stations were detailed for duties outside the Division, Factory Experiments Experiments T l to T3, T5 to T21, T23 to T25, T28, T30 and T31 have been concluded. High-country Experiments (St Coombs) T4 — Quality assessment of new clones — (1966) The clones assessed for quality are classified in Table 1. TABLE 1 — Quality assessment of clones Classification Group* 2 Estate Gonamotava Tangakelle Somerset St C o o m b s Bogawana St C o o m b s Clones G M T 9 W Y E727 T R I 62/1* T R I 62/5* B 2 7 5 * T R I 62/3* T R I 6 2 / 4 * T R I 62/6* Remarks Fir colour Greenish infusions, lacking colour St Coombs T R I 62/2* (see Kirtisinghe, de Silva & Samarasingham 1968) * Provisional classifications T22 — Tat withering under controlled conditions of temperature, humidity and airflow rate — (1966) This experiment has been abandoned because it has not been possible to effect the necessary repairs in the machine. A. Thevathasan T26 — Handpicking, shearing and machine harvesting of low-jat seedling tea from Pedro Estate, Nuwara Eliya, on yield and manufacturing properties (P67) — (1967) 102 ANNUAL REPORT FOR 1968 103 The experiment was carried out to determine made tea characteristics of tea harvested with three different types of mechanical pluckers. In the initial stage of this experiment, leaf from all 16 plots were plucked by hand to deter­ mine homogenity. The results of this preliminary experiment show that there are no inherent differences between the teas from these plots. In the second stage of this experiment leaf from 12 of these plots were harvested with three different types of mechanical pluckers and four plots were plucked by hand as a control. The teas were manufactured on an experi­ mental scale and evaluated by the TRI taster as well as by a panel of tasters in Colombo. The results of the evaluations are summarized in Tables 2 and 3 respectively. TABLE 2 — The effect of the use of mechanical pluckers compared with handplucking on made tea charac­ teristics as assessed by the TRI taster Treatments Infusion Colour Strength Quality Valuation (cents) Handpicking 5 . 0 5 . 2 4 . 0 4 . 4 1 4 1 . 2 Ochiai 4 . 9 5 . 1 4 . 1 4 . 5 147.1 Robin 4 . 1 5 . 3 3 . 4 3 . 5 9 3 . 3 Shears 4 . 1 5 .1 3 . 3 3 . 4 7 8 . 5 L S D (P = 0 . 0 5 ) 0 . 1 6 N S 0 . 5 5 0 . 7 4 1 3 . 2 5 TABLE 3 — The effect of the use of mechanical pluckers compared with handplucking on made tea characteristics as assessed by the Colombo panel of tasters Treatments Infusion Colour Strength Quality Valuation (cents) Handpicking 3 . 9 5 , 6 4 . 4 3 . 8 - 1 4 0 . 2 Ochiai 3 . 9 5 . 2 4 . 4 3 . 8 1 4 1 . 6 Robin 3 . 9 5 . 6 4 . 3 3 . 6 133 .5 Shears 3 . 7 5 . 4 4 . 3 3 . 2 1 2 1 . 2 L S D CT — 0 . 0 5 ) N S - N S N S N S 1 3 . 2 Evaluations by the TRI taster indicate that the BOP's from low jat leaf gathered with the Ochiai machine produced a tea as good as that handpicked. The leaf from the Robin machine was inferior to both these treatments but was better than that gathered with the shears. The trends from the reports of the Colombo panel of tasters were similar but the only statistically significant difference that emerged was that the shear plucked leaf produced a tea that was worth less than that gathered by hand or with the Ochiai machine. R. L. de Silva & S. Samarasingham T27 — Time of plucking on the liquoring characteristics of made tea —(1967) The object of this experiment was to determine whether the time of pluc­ king has any noticeable effect on the characteristics of the resultant tea. Two adjacent plots in a field, one planted with clone TRI 777 and the other with seedling tea, were selected for the experiment. Each of these plots was divi­ ded into three sections and these sections were plucked at 07 hr, 11 hr and 15 hr respectively on an eight-day round. The sections plucked at different times were in a randomized order and the experiment was carried out over five plucking rounds. 104 ANNUAL REPORT FOR 1968 Teas were manufactured on a miniature scale and evaluated by the TRI taster. The results indicate that teas produced from leaf plucked at different times, were not different with respect to all made tea characteristics. N . M. Abdul Gaffer T29 — Evaluation of the merits of preconditioning in mixed orthodox-rotorvane manufacture — (1967) This experiment was carried out to study the effect of preconditioning withered leaf in an orthodox roller before rotorvaning in a programme of mixed orthodox-rotorvane manufacture. The treatments applied were : 1 — Ten minutes preconditioning roll, one rotorvane pass and two x 30 min. orthodox rolls, 2 — No preconditioning roll, one rotorvane pass and two x 30 min. orthodox rolls, 3 — No preconditioning, two rotorvane passes. The liquoring properties of teas were evaluated by a taster in Colombo and also by the TRI taster. The Colombo taster did not report differences between any of the treatments for both BOP and BOPF grades. The TRI taster could detect no significant differences between the BOPF grades after any of the treatments. His report on the characteristics of the BOP grades is summarized in Table 4. TABLE 4 — Characteristics of BOP assessed by the TRI taster Treatments Infusion Colour Strength Quality Valuation (cents) 1 5 . 2 5 . 6 4 . 7 5 . 5 2 8 0 . 0 2 5 . 2 5 .8 4 . 7 5 . 2 " - 2 5 4 . 2 3 5 . 2 5 . 7 4 . 6 5 . 2 2 5 2 . 5 L S D (P = 0 .05 ) N S N S N S 0 . 2 8 8 . 8 ( P = 0 . 0 1 ) — — • — N S 1 2 . 0 The TRI taster could detect ho significant differences in the BOPs from these three treatments with regard to the infusion, colour and strength. He, however, preferred the treatment which consisted of a ten-min. preconditio­ ning roll, one rotorvane pass and two x 30 min. orthodox rolls to the other two treatments with regard to quality and over-all valuation. T32 — Drier project — (1967) Development work on the tea drier was carried out at the Low-Country Station. See LT9.for,progress on this experiment, W. Joseph & C. Kandappah 1968 Experiments T33 — Paper sacks as a substitute for tea chests — (1968) A trial was conducted to ascertain the suitability of paper sacks for shipping Ceylon teas. .The sacks had two layers of polyethylene film as waterproof inner liner. The consignment was shipped to a London firm, who reported ANNUAL REPORT FOR 1968 105 that they arrived in very good mechanical condition. The teas were reported as having a musty taste. It would therefore appear that there is no suitable alternative yet to plywood chests for shipping high-quality teas. T34 — Fermentation of teas in an atmosphere of carbon dioxide — (1968) The object of this experiment was to determine whether quality and flavour could be enhanced by allowing dhools to ferment in an atmosphere of carbon dioxide. A mixture of carbon dioxide and air in the ratio of 3 :2 by volume was passed through water and then into a tent made of polythene, where dhool was allowed to ferment. At the same time, another portion of the same dhool was allowed to ferment under normal ambient conditions (control). Experiments were carried out with different dhools which were also allowed to ferment for varying periods of time. Teas were fired, graded and evaluated by the TRI taster on 15 occasions. He found no detectable differen­ ces between the carbon dioxide-treated teas and the controls. N . M. Abdul; Gaffar T35 — Comparison of trough withering with withering on nylon tats and hessian tats during the quality season — 3 x 3 Latin square replicated 4 times — (1968) Leaf plucked at different times (morning, noon arid evening) was withered on nylon and hessian tats as well as by the use of a trough. Treatments were arranged in four replicates of 3x3 latin squares in order to eliminate the varia­ tion resulting from times of plucking (morning, noon or evening) and days of manufacture. Only one of the withering treatments was given to leaf plucked at any one time. The type of treatment given was governed by the latin square arrangement. The average periods of wither were 10|„ 9 | and 6£ hr for morning, noon and evening leaf respectively. Leaf was given four 30-min. orthodox rolls. BOP and BOPF grades were evaluated by the TRI taster as well as by a panel of tasters in Colombo. Results are presented in Tables 5 to 7. : TABLE 5 — Comparison of trough withering with withering'' on hessian and nylon tats—Made tea charac­ teristics of BOP as assessed by the TRI taster Treatments Nylon Hessian Trough L S D (P = 0 .05) TABLE 6 — Comparison of trough withering with withering on hessian and nylon tats—Made tea charac­ teristics of BOPF as assessed by the TRI taster Treatment N y l o n Hessian Trough L S D (/> = 0 .05 ) Infusion Colour Strength Quality ' Valuation ' (cents) 5 . 0 0 5 . 0 4 4 . 8 3 N S 5 . 4 4 5 .08 5 .38 0 .263 4 . 4 2 4 . 3 3 4 . 3 8 N S 5 .08 4 . 9 2 5 .08 N S i 2 3 1 . 9 .' 2 2 8 . 3 .' 222 .1 ; N S Infusion Colour Strength Quality Valuation (cents) 5 . 4 2 5 .46 5 .38 N S 6 .08 5 . 9 2 5 .88 N S 5 . 6 2 5 .71 5 .33 0 .273 5 . 9 2 ; 5 .71 : 5 .88 ; N S 3 0 0 . 0 2 9 0 . 8 2 9 3 . 8 N S 106 ANNUAL REPORT FOR 1968 TABLE 7 — Comparison of trough withering with withering on hessian and nylon tats—Made tea charac­ teristics of BOPF as assessed by the Colombo panel of tasters Treatment N y l o n Hessian Trough L S D ( P = 0 .05 ) Infusion 5 . 9 2 6 . 5 0 5 .83 N S Colour 6 .08 6 .58 5 .33 0 . 4 8 2 Strentgh Quality 6 .75 7 .25 6 .25 0 . 4 2 7 6 .08 6 . 4 2 6 . 5 0 N S Valuation (cents) 2 7 1 . 2 286 .7 2 7 9 . 6 N S TRI taster considered the colour of BOP liquor of nylon and trough- withered leaf, preferable to that of hessian-withered leaf. He could not detect any differences between the three treatments with respect to other character­ istics of the BOP grade. The Colombo panel of tasters could not detect any differences between any treatments for the BOP grades. The strength of BOPF liquors of nylon-withered and hessian-withered leaf was preferred to that of trough-withered leaf by the TRI taster. He could not detect any differences in the infusions, colour and quality between treatments, and overall valuations were not significantly different for the BOPF grades. The Colombo panel of tasters considered the colour of BOPF of hessian- withered leaf to be superior to that of nylon-withered leaf, which in turn was considered to be better than that of trough-withered leaf. The strength of the BOPF grade was considered to follow a similar trend. They could not detect any significant differences between treatments for the BOPF grade for other characteristics. T36 — Blending of clone TRI 2025 with clones possessing excellent quality — (1968) This experiment was carried out to ascertain whether the blending of TRI 2025 (Group 4 classification, Kirtisinghe et al. 1968) with clones DTI and TRI 777 (Group 1 classification) is an economic proposition. Blending was car­ ried out both before and after manufacture. The teas were manufactured on a miniature scale. The different blends and the pure clonal teas were : 1—TRI 2025 2 —TRI 777 3 — DTI 4 — TRI 2025 and TRI 777 mixed in the ratio of 1 : 1 in the roller 5 — TRI 2025 and DTI mixed in the ratio of 1 : 1 in the roller 6 — TRI 2025, TRI 777 and DTI mixed in the ratio of 1 : 1 : 1 in the roller 7 — TRI 2025 and TRI 777 mixed in the ratio of 1 : 1 after manufac­ ture 8 — TRI 2025 and DTI mixed in the ratio of 1 : 1 after manufacture 9 — TRI 2025, TRI 777 and DTI mixed in the ratio of 1 : 1 : 1 after manufacture. The results have still to be analysed, and will be published in a separate paper. S. Samarasingham ANNUAL REPORT FOR 1968 107 Low-Country Experiments (St Joachim) Experiments LT1 to LT3, and LT5 to LT7 have been concluded. LT4 — Rotorvane-CTC manufacture in the Low-Country — (1967) Teas produced during the latter part of 1967 were found to be acceptable by the trade. Commercial production of Rotorvane-CTC teas continued up to June 1968. A schedule of opinions expressed by the tea trade are given below. Schedule of opinion on low-country Ceylon CTC teas ex St Joachim Estate Broker (London) Leaf is black to rather grey. It is even and free from stalk and fibre, but it has the dis­ advantage of being gritty, for the small ball-like particles o f leaf will not assimilate in a blend. N o doubt a little attention in manufacture, perhaps in withering, can overcome this severe disadvantage. Infused leaf is bright and rather green; it could be more even. Liquors, though a little raw and harsh, are bright, have good strength and cream up well. They are red o n the milk. The value on the liquor only on today's market is 4s Od for the BOP and 4s 3d for the • BOPF. Conclusion : These samples certainly give the impression of good mid-country tea, taking only the liquoring- character into consideration. We would value them at 6d t o 9d per lb above the low-grown average. Blender (London) B O P Leaf — neat, even shot-like appearance Infused leaf — bright Liquor — light, bright with milk, brisk and g o o d flavour. B O P F Leaf — small, neat even Infused leaf — bright Liquor — more colour than the BOP, bright with milk, brisk and good flavour. Comments : Both teas would be veiy useful for blending purposes giving a blend character and flavour. More fannings would be required than the broken. With the modern packeting machines n o w operating in most factories the density o f this type of manufactured tea might cause some problems. Blender (London) T h e samples o f B O P and B O P F o f C T C manufacture from St Joachim were most in­ teresting, the liquors proving bright and useful. The leaf of both teas is very black and c o m ­ pares favourably with other Ceylon C T C sorts. There is some sales resistance to increasing quantities o f C T C manufacture, and well-made sizey B O P F with flavour are an attraction, but o n the other hand the liquors of these two teas seem to have been improved considerably. In the case of the BOP the leaf is rather brittle and too shotty to suit all buyers. Packer & Distributor (Manchester) B O P F G o o d black leaf, bright infusion—Reasonably thick in liquor—Price approximately 4s Od—Useful tea as price reducer. BOP Neat black leaf, bright infusion—Thin in liquor—Price approximately 3s lOd—Both teas slightly astringent in taste. Both teas are excellent price reducers but would come out very much better in the London water and possibly might be used for this purpose. Packer & Distributor (Liverpool) > This Company were not very keen o n either of these teas and did not think they came out very well in this water and could only be used as price reducers. Both teas came out quite well in Manchester water but evidently Liverpool water is very different from Man­ chester water. 108 ANNUAL REPORT FOR 1968 National Tea Distributor Our information is that these would not be suitable for the catering trade. They all seem surprisingly thin for this type of manufacture and lacking in body. W e have seen Ceylon teas from the States that have changed from orthodox t o C T C resulting in much fuller liquors but these seem to be the exception. LT8 — Live shade on the manufacturing properties of tea — (1967) The experiment has been concluded but the results have still to be ana­ lysed. T. F . Saldin LT9 — Drier project — (1967) Research activity centered mainly round the application of fluid bed technique to the drying of tea. Satisfactory fluidization of low-country CTC tea was achieved on a flat bed drier and indications have also been obtained that an appreciable fuel saving on more conventional drying technique was also possible. The liquoring characteristics of these teas were not significantly different to those of the same manufacture dried in an ECP drier. Further development of the drier is needed before it can find application in the drying of teas rolled in the orthodox manner. The project has suffered a set back because the firm with whom the Institute was collaborating on this project changed hands while the experiments were in progress. W. Joseph & C. Kandappah 1968 Experiments LT10 — Instant tea project — (1968) Experiments with the manufacture of instant tea were carried out in colla­ boration with the Biochemist. The samples manufactured at St Coombs represented a significant improvement on the samples manufactured hitherto by the spray-drying process. The equipment was sent to the Low-Country Station in May and has not functioned satisfactorily since. S. Jayaratnam LT11 — Manufacture of low-grown leaf allow temperatures — (1968) Leaf was withered, rolled and fermented at 60°F, 70°F and at ambient temperatures (about 80°F). Graded samples could not be evaluated because the tea-taster left the service of the TRI. C. Kandappah Mid-Country Experiments Experiments MT2 and MT3 have been concluded Experimental progress was affected during the second half of the year under review because the tea samples manufactured at this Station could not be evaluated by a tea taster. MT1 ; — Quality assessments of clones — (1966) Of the 18 clones tested during the year, MO 209, CW 21 and H 1/58 show great promise. On account of the difficulties that arose in having the manu­ factured samples evalauted by a tea taster, these clones have to be re-tested and evaluated again before a final assessment of quality is possible. Clones assessed for quality are classified in Table 8. A N N U A L REPORT FOR 1968 109 TABLE 8 — Quality assessment of new clones (Mid-Country) Origin Classification Group 2 Passara Classification Group 3 St Coombs Canaverella Craighead Diyagama Endane Kenilworth Nayabedde Pitakande Somerset ... W o o t o n Classification Group 4 St C o o m b s Balangoda Canaverella Craig Classification Group 5 St C o o m b s Thotulagalla Tangakelle Clone Remarks Clones with good manufacturing quality M P A 1 G o o d colour and strength Clones with satisfactory manufacturing quality T R I 2026 T R I 2151 D G 7 D G 39 C V 4 B 1 N K 4 B29 M G 3 B l C H 13 G N E N 31 K E N 16/3 N A Y 3 W 2/145 E 7/27 W3 G o o d strength Bright infusions, lacking in colour G o o d infusions, colour and strength G o o d infusions ; G o o d colour < Dul l infusions G o o d infusions G o o d colour G o o d infusions, colour and strength needs further testing G o o d infusions, colour and strength needs further testing Poor infusions, insufficient colour Clones with little manufacturing quality T R I 2022 Dul l infusions B G 18 Poor infusions, insufficient colour M T / B G — CVS B l Poor colour C R 4 — Clones with poor manufacturing quality TRI 2043 Coppery infusions T 5/3 Poor infusions, lacking in strength C Y 9 Poor strength MT4 — Plucking rounds-cam-plucked unit — (1967) This experiment aims at determining the effect of plucking rounds of different durations (four, six and twelve days rounds) and the type of plucked units (a bud and either one, two or three leaves) on the liquoring characteristics of made tea. Pre-treatment manufactures were concluded. Analysis of tasters' reports indicated no significant differences between the leaf from each of the experimental plot. The treatments were given in May. The experiment is in progress. MT5 — Gramoxone (and hand weeding in combination with 2 levels of nitrogen) on made tea characteristics — (1967) The manufacturing properties of leaf from plots to which eight weed con­ trol treatments (in MW1) are being applied, were compared, and the differences were not found to be significant. There were also no significant differences in made tea characteristics between leaf from plots receiving 100 lb and 200 lb nitrogen per acre per annum. Gramoxone-sprayed teas were reported to be taint-free. The experimental area was pruned in October. MT6 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels and 3 levels ofKon made tea characteristics — (1967) This experiment was carried out in conjunction with the District Advisory Officer (Mid-Country). Pre-treatment tests were concluded and no significant differences were observed between the leaf from the experimental plots. The treatment applications were done in June and October and the manufacturing tests are in progress. 110 ANNUAL REPORT FOR 1968 MT7 — Age from prune on the characteristics of made tea — (1967) The aim of this experiment is to determine the liquoring characteristics of made tea in relation to age from pruning. Pre-treatment manufacturing tests were concluded. The experimental plots have been divided into three groups of which the first one was pruned in October. The second and the third groups will be pruned in 1969 and 1970 respectively, so that at the end of the third year (1970), the green leaf from the tea bushes that aged in the three successive years from the prune, could be tested simultaneously. Manufactur­ ing tests will begin, after the tea recovers from pruning. T. A. Munasinghe St Coombs factory The nett sale average for teas manufactured at St Coombs factory for the year under review was Rs 2.29. Prices were satisfactory mainly because a reasonable standard of leaf arriving at the factory was maintained for most of the year and also because fewer experiments were carried out on a factory scale as a consequence of staff problems, making it easier to maintain a uniform standard of manufacture. Trough withering followed by a mixed orthodox-rotorvane rolling pro­ gramme was adopted in the factory. The process consisted of a 15 min. _ condition roll with little pressure, one rotorvane pass followed by two conven­ tional rolls of 30 min. duration reducing the bulk to under ten per cent. The period of fermentation ranged from a minimum of 1 hr 45 min. during the quality season in February/March to a maximum of three hr for one day in November. During the rush period a period of about two hr 45 min. was given for fermentation. Visits, Lectures and Symposia Dr D. Kirtisinghe addressed the following District Planters' Associations on matters relating to manufacture, developments in machinery and on fac­ tory designs: Kelani Valley, Uva, Kandy and Galle. Dr Kirtisinghe also served as a member on the Bureau of Ceylon Standards Drafting Sub-committee on tea. Acknowledgements Assistance given to us by several tea tasters in Colombo and useful discussions with some members of the TRI staff in other research divisions are gratefully acknowledged. Publications KIRTISINGHE, D., DE SILVA, W. A. C , SAMARASINGHAM, S., (1968). Manufac­ turing properties of Ceylon tea clones. Tea Q. 39, 29-36. MORRIS, P. J., KIRTISINGHE, D. & STRICKLAND-CONSTABLE, R. F., (1968). Retardation of growth of salol crystals in the melt in capillary tubes. J. Crystal Growth. 2,97-105. REPORT OF THE STATISTICS DIVISION Statistician — P. Kanapathipillai, BSc, FSS General The staff position was the same as last year. In addition to his normal duties, the Statistician was appointed Acting Chief Administrative Officer with effect from October 15th. The Statistician also continued to function as Convener/Secretary of the Experimental & Estates Committee of the TRI. Design and Analyses The designs were all of the simple types viz randomized blocks, split- plots and 3 x 3 x 3 factorials. It is now standard practice in all field experiments, to use pre-treatment data for covariance analyses. A measure of the gain in precision can be seen from the figures given in the last column of the follow­ ing table. The variation within the experiment is given by the coefficient of variation. Range of Mode of coefficients Gain analyses of variation range Analysis of covariance 3%—50% 175%—880% Analysis of 11%—48% covariance Types of design No. of Ex­ periments Randomized blocks (with suitable 70 transformations where necessary) Randomized blocks 80 Split-plot . 4 Analysis of 6%—14% — covariance Over 150 field experiments were analysed and the results further partitioned into meaningful single degrees of freedom. The statistical interpretations of the results of such analyses were also given. Computer Processing The volume of data flowing into the Division for statistical analyses has steadily increased to an extent that it has now become impossible for one technical assistant to cope with this rush. Consequently, the feasibility of processing experimental data on the ICI Computer at the State Engineering Corporation was examined. It is heartening to note that the Corporation has already undertaken the task of preparing programmes for the two types of design most commonly used viz randomized blocks and 3 x 3 x 3 factorials. The cost of these operations was found to be a small fraction compared with the cost of recruiting additional technical staff. In the case of 3 x 3 x 3 factorial it was found that this particular computer was able not only to produce the final analysis of variance of table but also to print the intermediate stages of the calculation viz all the two-way tables—very important components of the analysis for the study of interactions. As the inversion of matrices can also be done on this computer, the question of preparing programmes for multi­ variate analyses is also being considered. I l l REPORT ON THE LOW-COUNTRY STATION AND THE KOTTAWA SUBSTATION Director — L. H. Fernando, BSc, PhD Research Officer — D. T. Wettasinghe, BSc, PhD General The Low-Country Station, St Joachim, Ratnapura Dr L. H. Fernando was appointed Director of the Tea Research Institute and left St Joachim on the 28th December. Mr J. V. Sabanayagam, Advisory Officer, returned to Ceylon in June after successfully completing his post­ graduate studies and obtaining a Master's Degree in Science at the University of Guelph, Canada. He was initially stationed at St Coombs but was trans­ ferred to the Low-Country Station in December. Mr W. Joseph, Develop­ mental Engineer, was transferred to the Low-Country Station in June. Mr U. P. de S. Waidyanatha, Technical Assistant, left the service of the Institute in November. Mr R. I. Pereira, Chief Clerk, was appointed Accounting Assistant and was transferred to St Coombs in April. Mr W. J. Samuel succeeded him as Chief Clerk in May but returned to his substantive post at St Coombs in October, when Mr T. R. B. Sally was appointed to the post of Chief Clerk at the Low-Country Station. Mr K. D. B. H. Ateygunawardena, Accounts Clerk, was transferred back to St Coombs in June. Mr K. D. L. Nanayakkara was appointed Accounts Clerk in September and left after two months of service. Two junior staff quarters and two minor staff quarters were completed and officers went into occupation of them. The Kottawa Substation, Talgampola, Galle District Mr K. H. G. Gunapala remained in charge of the Substation. The results of experiments carried out at the Substation are presented in this report. Advisory Service The Assistant Director and the Research Officer continued to visit estates and address planters at District Associations. The Advisory Officer returned from overseas leave on 13th June 1968, and took over the advisory visits and correspondence with estates in the low country. The Institute participated in the Agricultural & Industrial Exhibitions in Ratnapura and Horana. Heptachlor was used to control Shot-hole Borer successfully on many estates in the low-country with less side effects of tea tortrix and looper or twig caterpillar attacks. Diseases of tea were not serious. Rim Blight with discoloured veins continued to occur in dry weather, following pruning or fertilizer application. Advice on fertilizer applications on estates was given in accordance with the results of low-country experiments. In old seedling tea a level of nitrogen ranging from 80 to 120 lb per acre along with 20 lb phosphoric acid (P 2 0 5 ) and 40 lb potash (K aO) per acre per year was found to be adequate. In younger seedling teas a maximum level of 200 lb nitrogen along with 28 lb P 2 0 5 and 90 lb K a O per acre per year was recommended.' In VP teas the, young tea manure mixture—T200 was recommended for the first two years from planting. 112 ANNUAL REPORT FOR 1968 113 In the third year, when plants are brought into plucking, 200 lb to 240 lb nitro­ gen along with 55 lb P a 0 5 and 120 lb K 2 0 per acre per year is recommended. Subsequently after a proper prune the levels of nitrogen may be increased to a maximum level of 360 lb per acre and phosphorus and potassium levels re­ duced to 28 l b P a 0 5 and 90 lb K 2 0 respectively. The use of Gramoxone at a rate of half pint in 50 gallons of water applied six times per year continued to be the chemical used in the weed control pro­ gramme on low-country estates. Karmex-diuron at the rate of f lb plus 15 fl; oz Surfactant N in 60 gallons water per acre was recommended to estates on an experimental basis. Many estates reported dieback of tea bushes and poor crop responses due to adverse weather conditions experienced in the early part of 1968. The clones TRI 2023 and TRI 2026 continued to be popular in low-country replanting programmes. The drought-tolerant clones DG 39, MT 18 and Sri- kandura S 106 were recommended to areas susceptible to prolonged droughts in the low-country districts. J. V. Sabanayagam Field Experiments and Trials The following experiments have been concluded : LA6, LA15, LA23, LA30, LW9, LW10, LW11 and LW12. LAI — NPKMg on seedling tea at Endane Estate, Kahawatte — (1955) The yields during the first year of the eighth experimental cycle 1968 to 1970 are presented in Table 1. TABLE 1 — Yield over the first year of the cycle 1967 to 1969 N P 2 O s 1st six months 2nd six months 1st year ! reatments Made tea per acre Made tea per acre Made tea per acre acre per year) (lb) (%) (lb) (%) (lb) (%) 0 411 100 890 100 1301 100 40 440 107 976 110 1415 109 80 443 108 1016 114 1459 112 0 436 100 967 100 1403 100 30 427 98 955 99 1381 . 9 8 60 430 99 959 99 1390 99 0 422 100 929 100 1351 100 40 439 104 979 105 1419 . 105 80 433 103 972 105 1405 104 0 425 100 951 100 1375 100 20 440 104 977 103 1417 103 40 428 101 953 100 1382 101 = 0 .05 ) 18 4 43 5 58 4 M g O L S D (P For the first time since the introduction of the present nitrogen levels in 1960 there was a response to nitrogen at 40 lb per acre per year in the first year of the cycle. Potash at 40 lb per acre per year has afso given a significant increase in yield, again for the first time since the introduction of the zero level five years ago in 1963. There is no response to phosphate. Twenty pounds per acre per year of magnesium oxide gave a significant yield response during the first six-months of the cycle. A . A . C. Karunaratne 114 ANNUAL REPORT FOR 1968 Treatments and 2nd years 3rd Year Cycle (lb per acre per year) (lb) (%) (lb) (%) (lb) (%) 75 3294 100 3493 100 3388 100 N 150 3614 110 3770 108 3637 107 225 3668 111 3790 109 3712 110 50 3440 100 3646 100 3496 100 K 2 0 100 3602 105 3718 102 3653 105 150 3533 103 3688 101 3588 103 0 3493 100 3576 100 3533 100 MgO 24 3546'' 102 3711 104 3605 102 48 3537 101 3715 104 3599 102 Interval between 12 3395 100 3675 100 3488 100 appli­ 10 3598 106 3715 101 3625 104 cations 8 3583 106 3662 100 3624 104 (weeks) L S D (/> = 0 .05 ) 110 3 152 4 104 3 The yields in successive years were 2569, 4485 and 3684 lb per acre; the third year yields may have been higher, but for the uncomfortably high plucking table (see Annual Report 1967) and the unprecedented drought early this year. Nitrogen at 75 lb per acre continued to sustain a yield as high as 3388 lb per acre; 150 and 225 lb N per acre increased this yield significantly by seven and ten per cent respectively. Increasing potash from 50 to 100 lb per acre per year raised the yield by five per cent, but increasing potash to 150 lb per acre did not increase the yield any further. The tea was pruned in June 1968 and the recovery was good; there were no casualties. The tea was brought into plucking 95 days after pruning. N . Yogaratnam LA3 — NPKMg shade on seedling tea at the Low-Country Station, Ratnapura-^ (1964) LA2 — NKMg and frequency of application on VP tea at Karapincha, Palm- garden Group, Ratnapura — (1961) The third experimental cycle which was extended to three years (1965 to 1968) has now been completed and the results are presented in Table 2. TABLE 2 — Mean yields of made tea in lb per acre per year during the three year cycle 1965 to 1968 at Karapincha, Palmgarden Yield of made tea per acre per year Mean of 1st ANNUAL REPORT FOR 1968 115 Treatments Yield (%) (lb per acre per year) (lb per acre) 75 1526 100 N 150 1555 102 225 1539 101 0 1516 100 P2O5 40 153Q 101 80 1574 104 0 1478 100 K s O 60 1565 106 120 1577 107 0 1441 100 M g O 24 1533 106 48 1645 114 L S D ( P = 0 .05 ) 114 7 Unshaded 1652 100 G.metadata shade at 14 ft x 14 ft 1534 93 G.tnaculata shade at 7 ft x 7 ft 1434 87 L S D ( P = 0 .05 ) 156 10 Although the difference in yield between 0 and 120 lb K 2 0 per acre was significant, there was no difference in yield between 60 and 120 lb K 2 0 per acre. There was a significant yield response to magnesium at 48 lb per acre per year respectively. Gliricidia maculata shade trees, spaced 7 ft x 7 ft apart caused a significant reduction in yield. H. H. Samarakoon LA4 — NPKMg on VP tea at the Kottawa Substation — (1963) This experiment was pruned in July after two and a half years of plucking. The results are summarized in Table 4. TABLE 4 Treatments (lb per acre per year) Nitrogen 75 150 225 Phosphate 0 30 60 Potash 0 50 100 Magnesia 0 30 L S D (P = 0 .05 ) - Mean yields in lb made tea per acre over the first cycle 1965 to 1968 First Second Third Fourth Fifth six months six months six months , six months six months (lb per (lb per (lb per (%) (lb per (%) (lb per (%) acre) (%) acre) (%) acre) acre) acre) 347 100 311 100 364 100 449 100 400 100 477 137 498 160 557 153 755 168 787 197 613 177 678 218 798 219 1058 235 952 238 389 100 406 100 469 100 665 100 651 100 487 125 510 126 596 127 825 124 746 115 561 144 571 141 654 139 772 116 742 114 463 100 481 100 547 100 722 100 567 100 473 102 497 103 579 106 740 102 754 133 501 108 510 106 593 108 800 111 818 144 460 100 488 100 561 100 734 100 656 100 447 97 475 97 538 96 694 95 715 109 530 115 524 107 620 111 834 114 768 117 91 19 88 18 98 17 122 16 132 19 The results of the two year cycle 1966 to 1968 are presented in Table 3. TABLE 3 — Yield in lb made tea per acre over the two-year cycle 1966 to 1968 116 ANNUAL REPORT FOR 1968 There were significant responses to nitrogen up to the highest level tested (225 lb per acre per year) throughout the first cycle. The large responses to phosphate observed in the early stages gradually decreased and in the fifth six-months period there was no significant response to the phosphate treatments. The response to potash at 50 lb per acre per year reached the level of signi­ ficance only in the fifth six-months period. The response to magnesia did not reach the level of significance throughout the cycle but appears to be in­ creasing with age. H. D . Jayasinghe LA5 — Zn, Nfrequency of application on seedling tea at the Low-Country Station, Ratnapura — (1963) This experiment is now in the third pruning cycle. Over the first 18 months of this cycle the highest yields were obtained with ten lb zinc sulphate and 125 lb nitrogen per acre per year, but the treatment differences were not signifi­ cant. E. J. B. de Silva LA7 — Rehabilitation : Species and fertilizer at the Low-Country Station, Ratnapura — (1963) The yields over the first eighteen months of plucking were not significantly different between treatments. LA8 — Rehabilitation with legumes at the Low-Country Station, Ratnapura — {1963) The yields over the first year of plucking did not reveal differences between the rehabilitation treatments. LA9 — Rehabilitation : Species, fertilizer and duration at the Low-Country Station, Ratnapura — (1965) The plants were given the first cut at 15 in. A visual assessment prior to this operation indicated that the best growth was made in the rehabilitated plots. An examination of height measurements and the weight of the cuttings also leads to a similar conclusion. The height and other growth measurements made on these plants will be analysed in greater detail later. N . Yogaratnam LA10 — Six clones at 3 levels of nitrogen and 3 levels of shade at the Low- Country Station, Ratnapura — (1965) All clones were brought into plucking on 8th July 1967, 25 months after planting. The yield during the first year of plucking is recorded in Table 5. ANNUAL REPORT FOR 1968 117 TABLE 5 — Yield in made tea lb per acre per year over the first year of plucking Clones Yield (lb per acre per year) (%) T R I 2023 1057 100 T R I 2026 1036 98 T R I 2043 683 65 M T 18 840 79 N 3 657 62 K E N 16/3 901 85 L S D (P = 0 .05 ) 108 10 Nitrogen (lb per acre per year) 4 0 668 100 80 967 145 120 953 143 L S D ( P = 0 .05 ) 287 43 Unshaded 854 100 G. maculate shade at 14 ft x 14 ft 815 95 G. maculata shade at 7 ft x 7 ft 918 107 L S D ( P = 0 .05 ) 287 34 TRI 2023 and TRI 2026 were superior to the other clones tested. There was a 45 % increase in yield when the nitrogen level was raised from 40 lb per acre per year to 80 lb per acre per year. As from October 1968 the nitrogen levels were increased to 80, 160 and 240 lb per acre per year. There was no difference between the shade treatments, but it should be mentioned that the shade trees had not grown sufficiently. LA11 — Bringing into bearing, plucking, pruning, levels of N and duration of cycle in VP tea at the Low-Country Station, Ratnapura — (1965) The yields of the first cycle (1966 to 1968) do not indicate significant differ­ ences between the nitrogen levels of 240, 320 and 400 lb per acre per year, nor between the three bringing into bearing treatments of one bending, two ben- dings and centering. D . D . K r o o n LA12 — 3 clones, 3 spacings and 3 levels of Nat the Kottawa Substation — (1961) In the first eighteen months of the third experimental cycle clone TRI 2024 gave the highest yield. Three hundred lb nitrogen per acre per year was better than 100 lb or 200 lb. There was no difference in yield between the spacing treatments 4 ft x 1J ft, 4 ft x 2 ft and 4 ft x 2\ ft. LA13 — 3 clones, 3 spacings and 3 levels of N at the Kottawa Substation — (1962) In the second two-year experimental cycle 1966 to 1968 there was no significant difference in yield between the three clones TRI 2023, 18B and TRI 2026, nor between the three spacings 4 ft x 14 in., 4 ft x 28 in. and 4 ft x 42 in. There was a significant yield response to nitrogen up to 300 lb per acre per year, the highest level tested. H. D . Jayasinghe LA14 — Spacing and fertilizer on VP tea at the Low-Country Station, Ratna­ pura— (1965) The tea was brought into plucking on 9th November 1967, 26 months after planting. The yield during the first year of plucking is presented in Table 6. l i s A N N U A L R E P O R T F O R im T A B L E 6 — Yield in lb made tea per acre over the first year. of plucking (November 1967 to October 1968) Treatment Nitrogen Yield (%) (lb per acre per year) (lb per acre per year) 50 732 100 100 865 118 150 990 135 Spacing between rows (ft) 3 . 5 869 100 4 . 0 879 101 4 . 5 839 93 Spacing within rows (ft) 1.5 896 100 2 . 0 793 89 2 . 5 907 101 L S D (P = 0 .05 ) 80 9 There was an 18% increase in yield when the nitrogen level was increased from 50 lb per acre to 100 lb per acre and a further increase of 17% in yield when the nitrogen level was increased to 150 lb per acre. As from October 1968 the nitrogen levels have been increased to 100, 200 and 300 lb per acre per year. There was no significant difference in yield between the spacing treatments, except in the case of the 2 ft within-row spacing which is lower than all other treatments tested; this is difficult to explain. D . D . K r o o n LA16 — NPKMg frequency of application on VP tea at Hunuwella, Opanaike— (1965) The yields over the two-year cycle 1966 to 1968 are presented in Table 7. TABLE 7 — Mean yields in lb made tea per acre at Hunuwella over the two-year cycle (1966 to 1968) Made tea per acre per year Treatments 1st year 2nd year Mean over the cycle ( lb per acre per year) (lb) (%) (lb) (%) (lb) (%) 120 3519 100 4785 100 4152 100 N 240 3819 109 5452 114 4635 112 360 3784 108 5424 113 4603 111 0 3697 100 5196 100 4446 100 PaOs 30 3740 101 5195 100 4467 100 60 3685 100 5269 101 4477 101 0 3748 100 5185 100 4466 100 KjjO 6 0 3726 99 5262 101 4494 101 120 3649 97 5213 101 4431 99 0 3796 100 5201 100 4498 100 M g O 25 3671 97 5293 102 4482 100 50 3655 96 5167 99 4411 98 Interval between 6 3863 100 5318 100 4590 100 applications 8 3738 97 5311 100 4524 99 (weeks) 10 3521 , 91 5032 95 4276 93 L S D (P - 0 . 0 5 ) 203 5 237 5 183 4 ANNUAL REPORT FOR 1968 119 (lb per acre per year) (lb per acre) (%) 240 8169 100 N 360 8360 102 480 8196 100 0 8060 100 P 2 O 5 30 8387 104 60 8278 103 0 8305 100 K a O 60 8169 98 120 8251 99 0 8223 100 M g O 25 8251 100 50 8251 100 Intervals between 8 8251 100 applications 6 8142 99 (weeks) 4 8332 101 L S D ( P = 0 .05) 218 S 3 There was a significant response to nitrogen up to 240 lb per acre per year during the first and second years of the cycle. Intervals of six and eight weeks between fertilizer applications were better than ten weeks. There was no response to phosphate, potash or magnesium treatments. A. A . C. Karunaratne LA17 — Types and levels of N, levels of dolomite on seedling tea at the Low- Country Station, Ratnapura — (1965) In this experiment, over the first 18 months of the present cycle (June 1967 to June 1969) the mean yield was 2,384 lb per acre. There was no significant difference in yield between the three forms of nitrogen viz sulphate of ammonia, calcium ammonium nitrate and urea, and the three levels of nitrogen viz 100, 200 and 300 lb per acre per year. These treatments have now been applied for a period of two and a half years. H. H. Samarakoon LA18 — Rehabilitation with legumes at the Low-Country Station, Ratnapura — (1966) These plants were cut across at 15 in. in December 1968. Differences in growth between treatments were not evident. N . Yogaratnam LA19 — Bringing into bearing, plucking, pruning and duration of cycle in VP tea at the Kottawa Substation — (1966) The frequency of plucking treatments viz every four, five and six days was introduced in November 1968. The results will be statistically analysed at the end of one year of plucking. H. D . Jayasinghe LA20 — NPKMg and frequency of application on VP tea at Ratnayaka Group, Deniyaya — (1966) The mean yields during the first eighteen months of the cycle 1967 to 1969 are presented in Table 8. TABLE 8 — Mean yields in lb made tea during the first 18 months of the cycle (1967 to 1969) Treatments Yield 120 ANNUAL REPORT FOR 1968 N 240 7499 100 360 7914 106 480 7878 105 0 7874 100 P2O5 30 7734 98 60 7683 98 0 7680 100 K 2 0 60 7818 102 120 7793 101 0 7737 100 M g O 25 7812 101 50 7743 100 Interval in weeks 8 7780 100 between 6 7797 100 applications 4 7715 99 L S D (i> = 0 .05) 368 5 There was a response to nitrogen up to 360 lb per acre per year. There was no response to the phosphate, potash and magnesia and frequency of ferti­ lizer application treatments. LA22 — NPKMg and frequency of application on seedling tea at Anningkande Estate, Deniyaya — (1966) The mean yields during the first eighteen months of the cycle 1966 to 1968 are presented in Table 10. TABLE 10 — Mean yields in lb made tea per acre during the first 18 months of the cycle (1966 to 1968) Treatments Yield (lb per acre per year) (lb per acre) (%) 100 4066 100 N 200 4066 100 300 4114 101 0 4162 100 P«©« 30 4017 97 60 4090 98 0 3993 100 K a O 60 4162 104 120 4090 102 0 4114 100 M g O 25 4090 99 50 4041 98 Interval in weeks 10 4090 100 between 8 4090 100 applications 6 4041 99 L S D ( P = 0 .05 ) 169 4 Potash at 60 lb K ? 0 per acre increased yield significantly. Although the yields were very high, there was no response to nitrogen beyond 240 lb. Phosphate at 30 lb P 2 O s per acre increased the yield signi­ ficantly, but not potash. LA21 — NPKMg and frequency of application on VP tea at Kobomella Group, Beralapantara — (1966) TABLE 9 — Mean yields in lb made tea per acre in the first eighteen months of the cycle (1967 to 1969) Treatments Yield (lb per acre per year) (made tea per acre) (%) A N N U A L R E P O R T F O R i968 i l l Treatments Yield (lb per acre per year) 0 b per acre per year) (%) 160 4754 100 N 320 5235 110 480 5411 ' 114 Interval in weeks 8 5027 100 between 6 5209 104 applications 4 5165 103 Sulphate of ammonia 5126 100 Urea 5159 101 Calcium ammonium nitrate 5116 100 Do lomi te (tons per acre per year) 0 4934 100 4 5257 107 1 5210 106 L S D (P = 0 .05) 272 5 There was a yield response up to 3201b nitrogen per acre per year and half ton dolomite per acre per year increased yields. The differences in yield between the frequency of application treatments and the forms of nitrogen were not significant. LA25 — 3 types of nitrogen (urea, calcium ammonium nitrate and sulphate of ammonia), 3 levels of N, 3 frequencies of application and 3 levels of dolomite on VP tea at Enselwatte Group, Deniyaya — (1966) There were no significant differences between treatment yields over, the first 18 months of the cycle 1967 to 1969. LA26 — Methods of priming, frequency of plucking and duration of cycle on VP tea at Handford Estate, Deniyaya — (1966) The yield for the first eighteen months of the cycle 1966 to 1968 are pre­ sented in Table 12. TABLE 12 — Mean yields in lb made tea per acre in the first eighteen months of the cycle 1966 to 1968 Treatments Yield Frequency of plucking (days) (lb per acre) . (%) 4 4972 100 5 4353 89 6 4262 86 Method of pruning Rim-lung 4519 100 Centre-lung 4522 100 Cut-across 4545 101 L S D (i> = 0 .05) 90 2 LA23 — 3 types of N, urea, calcium ammonium nitrate and sulphate of, am­ monia, 3 levels of N, 3 frequencies of application and 3 levels of dolomite on VP tea at Dankoluwa Estate, Pitabeddera — (1966) This experiment was terminated, following casualties in the plots during a period of unprecedented dry weather. LA24 — 3 types of N (urea, calcium ammonium nitrate and sulphate of ammonia), 3 levels of N, 3 frequencies of application and 3 levels of dolomite on VP tea at Deniyaya Estate, Deniyaya — (1966) The yields obtained over the two year cycle 1966 to 1968 are presented in Table 11. TABLE 11 — Mean yields in lb made tea per acre per year over the two-year cycle 1966 to 1968 122" ANNUAL REPORT FOR 1968 Treatments Yield Frequency of plucking (days) (lb per acre) (%) 5 4 4 4 3 1 0 0 6 4 0 3 6 9 1 7 3 8 9 1 8 8 Method o f pruning Rim-lung 4 1 0 1 1 0 0 Centre-lung 4 1 5 8 1 0 1 Cut-across 4 1 1 1 1 0 0 L S D (P = 0 . 0 5 ) 7 8 2 The differences in yield between pruning treatments were not significant. Plucking every five days gave a higher yield than plucking every six days. Plucking every seven days gave the lowest yield. J. I. H . Bandaranayake LA28 — NPK, types of N and levels of lime on VP tea at Hapugastenne Group, Ratnapura — (1966) The results obtained during the cycle 1966 to 1968 are presented in Table 14. TABLE 14 — Mean yields in lb made tea per acre per year over the cycle 1966 to 1968 Treatments Yield (lb per acre per year) (%) Sulphate of ammonia 3 5 1 2 1 0 0 Calcium ammonium nitrate 3 4 8 3 9 9 Urea 3 4 2 3 9 7 (lb per acre per year) 2 4 0 3 3 5 3 1 0 0 N 3 6 0 3 4 4 1 1 0 3 4 8 0 3 6 2 4 1 0 8 0 3 4 6 4 1 0 0 P 2 O B 3 0 3 4 9 2 1 0 1 6 0 3 4 6 3 1 0 0 0 3 4 7 7 1 0 0 K A O 6 0 3 4 8 6 1 0 0 1 2 0 3 4 5 6 9 9 Limbux (tons per acre per year) 0 3 5 2 9 1 0 0 i 3 4 9 4 9 9 1 3 3 9 6 9 6 L S D (P = 0 . 0 5 ) 1 2 8 4 Plucking every four days gave a significantly higher yield than plucking every five or six days. There was no difference in yield between the pruning methods. LA27 — Methods of pruning, frequency of plucking and duration of cycle on seedling tea at Anningkande Estate, Deniyaya — (1966) The yields obtained in the first eighteen months of the cycle 1967 to 1969 are presented in Table 13. TABLE 13 — Mean yields in lb made tea per acre over the first eighteen months of the cycle (1967 to 1969) A N N U A L R E P O R T F O R 1968 123 there was no significant difference in yield between sulphate of ammonia, calcium ammonium nitrate and urea. Four hundred and eighty pounds nitrogen per acre per year gave a significantly higher yield than 360 lb and 240 lb, but the increase in yield was only 183 lb made tea with 120 lb nitrogen. There was no yield response to phosphate and potash application ; Limbux at one ton per acre per year depressed yields. E. J. B . de Silva LA29 — NPK and frequency of application on seedling tea at Sapumalkande Group, Dehiowita — (1966) This experiment was due for pruning this year but the cycle was extended for another six months at the request of the Superintendent, Sapumalkande Group. The yields during the second year of the cycle (1966 to 1969) are given in Table 15. TABLE 15 — Mean yield in the second year of the cycle 1966 to 1969 (%) Treatments (lb per acre per year) Yield (lb per acre per year) N P a O S Interval between applications (weeks) L S D ( P = 0 . 0 5 ) 120 3664 100 240 3972 108 360 3962 108 0 3965 100 30 3768 95 60 3865 97 0 3963 100 60 3860 97 120 3773 95 9 3847 100 7 3778 98 5 3970 103 214 6 There was an 8 % increase in yield when the nitrogen was increased from 120 to 240 lb per acre per year with no further increase in yield with 360 lb N. There was no significant response to the other treatments. N . Yogaratnam LA31 — 3 types of nitrogen (urea, calcium ammonium nitrate and sulphate of ammonia), 3 levels of nitrogen, 3 frequencies of application and 3 levels of dolomite on VP tea at Talangaha Estate, Nakiyadeniya — (1966) The yields obtained in the first eighteen months of the cycled967 to 1969 are presented in Table 16. ' ) 114 A N N U A L REPORT FOR 1968 TABLE 16 — Mean yields in lb made tea per acre over the first eighteen months of the cycle 1967 to 1969 Treatments Yield (lb per acre per year) (%) Sulphate of ammonia 5051 100 Calcium ammonium nitrate 4602 ' 91 Urea 4732 94 (lb per acre per year) 240 4621 100 N 360 4865 105 480 4899 106 Interval between 8 4774 100 applications 6 4813 101 (weeks) 4 4798 101 Do lomi te (tons per acre per year) 0 4890 100 i 4800 98 1 4694 96 L S D (P = 0 .05 ) 253 5 Sulphate of ammonia gave significantly higher yields than calcium ammo­ nium nitrate, and urea. There is a significant response in yield up to 360 lb nitrogen per acre per year but not thereafter. L A 3 2 — 3 types of nitrogen (urea, calcium ammonium nitrate and sulphate of ammonia), 3 levels of nitrogen, 3 frequencies of application and 3 levels of dolomite on VP tea at Talgaswella Estate, Talgaswela — (1966) There were no significant differences between treatment yields over the first eighteen months of the cycle 1967 to 1969. H. D . Jayasinghe L A 3 3 — NPKMg and frequency of application on VP tea at Nil. Ella Estate, Morawaka — (1967) In this experiment the following treatments are being compared : nitrogen at 240, 360 and 480 lb per acre per year ; P 2 0 5 at 0, 30 and 60 lb per acre per year ; MgO at 0, 25 and 50 lb per acre per year, and 6, 8 and 12 fertilizer appli­ cations per year. Over the first eighteen months of the first experimental cycle there were no differences in yield between treatments. J. I. H . Bandaranayake L A 3 4 — NPKMg on VP tea at the Low-Country Station, Ratnapura — (1967) The plants were bent twice and then cut at 14 in. All plots were tipped at 18 in. in December 1968, and will be brought into plucking early next year. N . Yogaratnan. 1968 Experiments L A 3 5 — Levels of nitrogen, phosphorus, potassium and magnesium on young plants of TRI 2023 in pots at the Low-Country Station, Ratnapura 4 randomized blocks — (1968) . . ANNUAL REPORT FOR 1968 125 In this experiment, six levels each of sulphate of ammonia, saphosphos­ phate, muriate of potash and kieserite are being applied to young plants of clone TRI 2023 growing in cement pots. The plants will be allowed to grow freely. It is intended to study the nitrogen, phosphorus, potassium and magnesium contents of flush shoots and mature leaves in relation to the level of fertilizer application. Non-destructive assessments of growth will also be made. Each fertilizer is being tested in a separate experiment. D . T. Wettasinghe & N . S. Rajendram i LA36 — 3 levels of nitrogen on 4 clones at the Low-Country Station, Ratnapura — 4 randomized blocks — (1968) i In this experiment TRI 2023, TRI 2025, TRI 2026 and CW 21 are being tested at three levels of nitrogen viz 75, 150 and 225 lb per acre per year. The twelve treatment combinations are randomized within each block. This experiment was planted in July on old tea land which was not rehabilitated. The first bending was done in September 1968. N . Yogaratnam LVP1 to LVP6 — Clonal testing at the Kottawa Substation — (1961 to 1965) The results from these experiments are presented in the Report of the Plant Physiology Division and are, therefore, not repeated here. H. D . Jayasinghe LVP6 — Clonal testing at the Low-Country Station, Ratnapura — (1964) The tea was pruned in April and the bushes allowed to grow up for ob­ taining cuttings for propagation. The following clones whose performance was encouraging were selected for inclusion in a replicated experiment: TRI 2021, 2022, 2023, 2024, 2025, 2026, 2027, 2043, 2045 and 2151, CW 21, PGG 2, PUH 5, NK 4B 29, MT 18, DG39, DG 3, H 1/58, H 13/4, M 20, MPA 1, KEN 16/3 and GMT 9. LVP7 — Clonal selection at the Low-Country Station, Ratnapura — (1965) Selections from St Joachim , Of the 220 St Joachim selections, 23 were outstanding. These were pruned in November 1968 and allowed to grow up as a source of planting material. These clones will be included in a replicated experiment in 1969. Yield records are being maintained on the rest. Selections from Lansdowne TRI 2023 x 77?/ 2026 seedling All 116 selections were brought into plucking in December, 1968, eighteen months after planting. Selections from Endane seedlings These selections will be brought into plucking in January next year. D . D . K r o o n LVP8 — Clonal selection at the Kottawa Substation — (1966) Eleven selections are now in plucking. Yield records are being maintained. K. H. G. Gunapala 126 ANNUAL REPORT FOR 1968 LVP9 — Clonal selection for drought resistance at Rye Estate, Balangoda — (1966) • Eighty nine selections were planted out in rows of ten plants each, in November 1968. Five plants in each row were bent and the rest allowed to grow freely. D . D . K r o o n LPH2 — Methods of pruning seedling tea at the Low-Country Station, Ratna­ pura — (1966) This experiment was terminated at the end of the third six-months of the cycle 1966 to 1968. The yields during this period were similar to those obtained during the second six-months period (see Annual Report for 1967). Rira- luhg pruning gave a higher yield than centre-lung or cut-across pruning, but the difference was not significant. LPH3 — Duration of lung retention on recovery from pruning and on yield in seedling tea at the Low-Country Station, Ratnapura — (1966) The treatments are described fully in the Annual Report for 1966. The yields obtained for the two-year cycle, 1966 to 1968 are presented in Table 17. TABLE 17 — Mean yields in lb made tea per acre over the two year cycle 1966 to 1968 Treatments Yield (lb per acre) Pruning without lungs 1813 Pruned and lungs removed after 4 weeks 2604 Pruned and lungs removed after 11 weeks at (a) pruning level and tipped 4 in. above 2623 (b) 4 in. above pruning level and tipped at this same level 2844 (c) pruning level and tipped 8 in. above this 2634 L S D ( P = 0 .05 ) 335 The highest yields were obtained where lungs were removed after 11 weeks four in. above pruning level with tipping also done four in. above the pruning level. This experiment is terminated. LPH4 — Duration of lung retention on recovery from pruning and on yield of seedling tea at the Low-Country Station, Ratnapura — (1967) Over the first 18 months of the cycle 1967 to 1969 the highest yield was obtained where lungs were removed eight weeks after pruning. The results will be presented when the two-year experimental cycle is completed. N . S. Rajendram 1968 Experiments LPH5 —^Rlucking.the lungs on recovery from pruning and yield of seedling tea at the Low-Country Station, Ratnapura—3 randomized blocks — (1968) Rim-lung and centre-lung-pruned bushes, where the lungs were plucked, were compared with those where the lungs were not plucked. The lungs were removed eight weeks after pruning, and the tipping done either four or eight in. •above the pruning level. The tipping weights and the yields obtained during the first six months of the cycle are presented in Table 18. ANNUAL REPORT FOR 1968 127 TABLE 18 — Mean yields in lb made tea per acre over the first six months of the cycle 1968 to 1970 Made tea per acre Treatments Fresh weight o f tipping . First six months (lb per 0 . 0 2 acre plot) (lb) (%) Rim-lung pruning 1 2 . 8 3 187 100 Centre-lung pruning 8 . S 6 131 .81 Lungs plucked 11 .31 182 100 Lungs not plucked 1 0 . 0 8 157 8 6 Tipped at 4 inches 173 100 Tipped at 8 inches 166 96 L S D (P = 0 . 0 5 ) 21 12 Rim-lung pruning gave significantly higher yields than centre-lung pruning and confirms the results of previous experiments carried out at this Station. The yields obtained from plots where the lungs were plucked were signi­ ficantly higher than where the lungs were not plucked. N . S. Rajendram Evaluation of herbicides LW13 — Simazine, diuron, 2, 4-D and amitrole on the yields of seedling tea,— (1967) The treatments were applied on seven occasions. According to the treat­ ment given, the plots, therefore, received a total of 5.6 lb or 11.2 lb diuron ; 5.6 lb or 11.2 lb 2,4-D ; 7 lb or 14 lb simazine, 7 lb or 14 lb of amitrole, per acre within a period of 16 months. None of the above treatments had any effect on the yield of tea during this period. Soil samples were taken three months after the seventh application of the treatments. These samples will be bio-assayed for residues. D . T. Wettasinghe & U . P. de S. Waidyanatha LW14 — Pentachlorophenol on yield of seedling tea — (1967) In this experiment the highest rate tested viz 2.4 lb pentachlorophenol (PCP) monthly for a period of nine months, did not cause a significant reduction in the yield during this period. This experiment was abandoned as there were a number of casualties during the drought. LW15 — Primary evaluation of herbicides — (1967) Of the 15 materials tested the following have been selected for further evaluation in LW21—Fluometuron (Cotoran), metabromuron (Patoran), chloroxuron (Tenoran), chlorbromuron (Maloran), benzthiazuron (Gatnon), prometryne, desmetryne and NPH 1221. 1968 Experiments LW20 — Simazine, diuron, fluometuron and pentachlorophenol on the growth of young tea (clone TRI 2023) — 4 randomized blocks — (1968) The primary object of this experiment is to determine, the tolerance of young tea plants of clone TRI 2023 to soil applications of the following her­ bicides : Simazine at 0.5, 1.0 and 2.0 lb per acre ) t, Diuron at 0.2, 0.4 and 0.8 lb per acre Fluometuron at 0.2, 0.4 and 0.8 lb per acre, and Pentachlorophenol (sodium salt) at 1.5, 3.0 and 6.0 lb per acr$, . 128" ANNUAL REPORT FOR 1968 The first application was made 40 days after the tea was transplanted, and the treatments would be repeated at bi-monthly intervals. The spray is directed to the soil and care taken to avoid spraying the foliage. The plots are fre­ quently hand-weeded to prevent weed competition. The phytotoxicity of the herbicides will be determined by visual observations as well as growth assess­ ments. LW21 — Evaluation of herbicides — observation plots in duplicate — (1968) The following were screened for their residual effect on weeds when used as soil-applied herbicides : Fluometuron, metabromuron, chloroxuron, chlor- bromuron, benzthiazuron, prometryne and desmetryne—all at 0.5 and 1.5 lb per acre, and NPH 1221 at 1 and 3 lb per acre. The performance of these materials were assessed by visual rating and the following selected for further evaluation in LW22 : Fluometuron, chloro­ xuron, prometryne and desmetryne. D . T. Wettasinghe & H. H. Samarakoon LW22 — Evaluation of herbicides — 3 randomized blocks — (1968) The following are being screened for their residual effect on weeds when used as soil-applied herbicides in tea : Fluometuron, chloroxuron, linuron neburon, diuron and lenacil all at 0.6 and 1.2 lb per acre ; atrazine, atratone, desmetryne and prometryne, all at 0.5 and 1.0 lb per acre ; Propachlor at 0.65 lb per acre, CP 44939 at 1 and 2 lb per acre, PCP (Na) at 2.7 and 5.4 lb per acre, a trifluralin E.C. of unknown strength at 0.25 and 0.5 gallon per acre, Pesco 18-25 at 0.5 and 1.0 gallon per acre and Ustinex PA (containing diuron and amitrole) at 0.75 and 3.0 lb per acre. D . T. Wettasinghe & N . S. Rajendram Weed Control LW18 — Gramoxone, diuron, simazine and 2,4-D on one-year-old plants of clone TRI 2023 — (1967) The 2,4-D treatment controlled the dicotyledonous species but grasses such as Axonopus spp. and Digitaria spp. became predominant. The Gramo­ xone treatments were better but the control was inadequate, particularly of Borreria hispida (formerly Spermacoce latifolia). Simazine at- one lb per acre gave adequate control of weeds for about 2\ months but the plot had to be clean weeded before repeating the simazine treatment. Diuron at half lb per acre also gave about 2\ month weed control. The plots were not clean weeded before repeating the diuron treatments. It was necessary, however, to hand pull weeds growing in the tea row. This experiment has been concluded. 1968 Experiments LW19 — Control of a very dense stand of Paspalum conjugatum in tea — Randomized blocks in 3 replicates — (1968) Plots (16 ft x 24 ft) were demarcated in. an area where the tea had been recently uprooted. The weed growth was almost entirely Paspalum conjugatum. The following treatments were tested : 1 and 2 lb amitrole per acre ; 0.6 and 1.2 lb diuron per acre ; If and 3 pints Gramoxone per acre ; 0.25 and 0.5 lb amitrole per acre, each level being followed 14 days later by 0.4 lb diuron or 0.8 lb diuron, or J pint Gramoxone or 1 pint Gramoxone. All treatments were applied in a spray volume of 75 gallons water per acre. The degree of ANNUAL REPORT FOR 1968 129 weed control was assessed visually at approximately fortnightly intervals over a period of 2 | months. None of the above treatments gave complete control of the grass. The most effective treatments were the low rates of amitrole 0.25 and 0.5 lb per acre followed by either diuron or Gramoxone, all of which gave satisfactory control'of P.conjugation for almost 75 days. Amitrole at two lb per acre on its own also gave similar control but is a more expensive treatment. D . T. Wettasinghe & U . P. de S. Waidyanatha LW23 — Diuron for weed control in mature tea — 7 randomized blocks — (1968) In a number of experiments it has been shown that diuron is active against many weed species common in low-grown tea. Rates as low as 0.5 lb per acre have given good control for approximately two months. It may be possible to use higher rates safely and obtain a longer duration of weed control. In this experiment various levels of diuron, viz 0.5, 1.0, 1.5 and 2.0 lb per acre, are being tested to determine the most economical rate to bring about and maintain weed control. At the coinmencement of the experiment the plots had about 80 to 90% weed cover consisting mainly of Borreria hispidq Cleome burmanii, Paspalum spp. and Ageratum cpnyzoides. The treatments are repeated when the weed growth warrants it. A schedule of operations and weed growth assessments are given in Table 19. Crassocephalus crepidioides appeared in most plots in November, and as this weed seemed quite resistant to diuron it was hand-pulled and the weight per plot recorded. iThe apparently better control of C.crepidioides at the lower levels of diuron may be due to some contact effect of the October applications which were confined to the £ and 1 lb per acre levels. The plots were clean weeded in December, and the weight of all weeds recorded. Treatment 2 (3 applications of 1 lb diuron per acre) appears to be the most effective in bringing about weed control. The treatments will be resumed next year and carried out over a full year to determine the most economic level to maintain control. LW24 — Diuron for weed control in shaded and unshaded mature tea—Split plot with shade in main plots, diuron in subplots with 3 replicates — (1968) The experiment is similar to LW23. All treatments have been repeated once, three months after the initial application. The experimnt is in progress. LW25 — Control of Paspalum conjugatum—3 randomized-blocks — (1968) The following treatments are being tested : 1 — D + S 2 — D + £ pint Gramoxone + S 3 — D + | pint Gramoxone + S 4 — D •+ 1/8 pint Gramoxone +. S 5 — D + £ pint Gramoxone 6 — D -f I pint Gramoxone 7 — D + 1/8 pint Gramoxone 8 — Control D = 0.6 lb diuron per acre S = 0.75 pint surfactant 'N' per acre All treatments were applied in a spray volume of 50 gallons per acre. D. T . Wettasinghe & N . - S . Rajendram TABLE 19 — Schedule of operations and weed assessments in LW23 Applied o n Appl ied o n Appl ied o n Fresh weight lb Plots clean weeded o n Treatment 3 0 . 4 . 6 8 % w e e d c o v e r 2 . 8 . 6 8 % weed cover 1 0 . 1 0 . 6 8 of C.crepidiodies % weed cover 1 7 . 1 2 . 6 8 . Fresh weight ( l b p e r a c r e ) 2 . 8 . 6 7 ( l b p e r a c r e ) 5 . 1 0 . 6 7 (lb per acre) 2 9 . 1 1 , 6 8 1 3 . 1 2 . 6 8 of all weeds (lb) 1 0 . 5 47 0 . 5 50 0 . 5 9 . 0 38 5 2 . 2 2. J 37 1 41 1 7 . 0 30 2 3 . 3 3 1.5 24 1 .5 19 — 1 9 . 3 32 3 3 . 5 4 2 32 2 . 29 — 2 2 . 7 31 3 9 . 7 L S D (P = 0 . 0 5 ) 6 . 6 2 7 . 1 ANNUAL REPORT FOR 1968 131 Weed competition -...•••„ LW5— Weed effects on crop and yield of seedling tea at the Low-Country Sta­ tion, Ratnapura — (1965) ' ; This experiment was pruned in May 1967. Following pruning there was a profuse growth of weeds, particularly creepers, which threatened to smother the tea. Creepers originated in the four-monthly and six-monthly weeded plots but invaded all plots; all plpts had.to be..plean-weeded rfianually in Octo­ ber 1967. The original treatments were applied[thereafter. The yields obtained in the first year of the cycle 1967-1968 are recorded in Table 20. ;" " '' TABLE 20 — Mean yield in lb made tea, per. acre in the first year of the cycle 1967 to 1969 Yield Ob per acre) Treatments , N levels 1 100 200 (lb per acre) : Mean Weeds removed every 2 months Weeds removed every 4 months Weeds removed every 6 months Gramoxone J pint per acre 1144 " 1 2 4 4 1003 1183 983 1041 1138 1118 1194 1093 1012 • 1 1 2 8 L S D (-P - 0 .05) .164 '• • ^ : it ••' 1 1 6 " Mean ' .2458 2658 : . . . L S D (P = 0 .05) 82 Manual weeding at two-monthly intervals and QramQXonq,appUcations at two-monthly gave significantly higher yields'Hhan weeding at six-monthly intervals. Nitrogen at 200 lb per acre per year gave a higher yield than 100 lb per acre per year, but the difference just failed to reach the level of significance. - U . P . d e S . Wajdyanatha LW16 — Competitive effect of weeds on the growth of young tea T T 5 randomized blocks — (1967) \c. Six months after the commencement of the treatments the plants were cut at eight in. above ground level and the dry weights of. the tops were determined and used to assess the effect of weed competition. The best growth was made by plants in plots weeded every two or every four weeks, and made nearly twice the growth in plots weeded every ten weeks. The plants in plots weeded six and eight weeks were intermediate. The main weeds present were Axono- pus affinis and Borreria hispida. D . T. Wettasinghe & H. H . Samarakoon Weed biology .... : : ;; LW17 — Seasonal pattern of weed emergence under mature seedling tea— 8 .. paired plots — (1967) . _ , .. Routine counts were kept and will be continued for another year before attempting to analyse the data. D . T. Wettasinghe & U . P. de S. Waidyanatha 132 ANNUAL REPORT FOR 1968 L W 2 6 — Herbarium of weeds — (1968) A herbarium of weeds in low-grown tea is being compiled. Seventeen species have been collected and are being prepared. D . T . Wettasinghe & N ; S. Rajendram . Miscellaneous L W 2 7 — Paraquat on bud break in pruned tea—4 randomized blocks — (1968) Paraquat is used en some estates as an overall application after pruning to control moss and ferns growing on the frames. This experiment was designed to study the effect of the above practice on bud break. The following treatments were tested : 1 — 0.05% paraquat applied on the day of pruning 2 — 0.05 % paraquat applied 5 days after pruning 3 — 0.05% paraquat applied lO.days after pruning 4 — 0.05% paraquat applied 15 days after pruning 5 — 0.05% paraquat applied 20 days after pruning 6 — Control. The paraquat was applied with a paint brush on to the frames. The tea was clean pruned to facilitate the application of treatments, but this together with particularly unfavourable weather resulted in poor and delayed bud break. This experiment will be repeated. D . T . Wettasinghe & N . S. Rajendram L W 2 8 — Fotmulatioti of diuron — (1968) Diuron is a residual herbicide which is taken up into plants mainly through the roots. It has been shown that foliar uptake may be increased by the addition of surfactants (McWhorter and Sheets 1961). Commercial formulations do not, however, seem to have adequate foliar activity. Experi­ ments indicate that the addition of surfactant 'N' (octylphenol/ethylene oxide condensate) at the rate-of £ pint of the surfactant to 50 gallons of the spray solution considerably increased the foliar activity of diuron. It was observed that environmental factors such as temperature, light intensity and humidity at the time of application greatly influenced the activity of diuron. The effect of these factors or the optimum level of surfactant cannot be determined until precision equipment is available. 1 D . T . Wettasinghe & H. H . Samarakoon Extension Experiments XLA1 — 3 types and 3 levels of nitrogen (urea, calcium ammonium nitrate, sulphate of ammonia) and 3 levels of lime on VP tea at Hunuwella Group, Opanaike — (1965) The yields recorded over the two-year cycle 1966 to 1968 do not show significant differences.between the treatments tested. During the second year of the cycle, however, 360 lb N per acre per year gave an yield of 5,444 lb made tea per acre which was eight percent more and significantly better than at 240 lb N. ANNUAL REPORT FOR 1968 133 Treatments Nitrogen 2nd Year Mean of cycle Ob per acre per year) (made tea per acre) (%) (made tea per acre) (%) 0 4647 100 3871 100 120 5798 125 4655 120 240 6276 135 5158 133 360 6196 133 5168 133 L S D (P = 0 .05 ) 483 10 4ph ; 10 N o shade 5704 99 4732 101 Shade 5755 100 4696 100 L S D (P = 0 .05 ) 1471 26 1259 27 The response to nitrogen extends up to 240 lb per acre per year but not beyond this. The difference in yield between shaded and unshaded plots is not significant. XLA4 — 4 levels of nitrogen x 2 levels of shade on seedling tea at Hunuwella Group, Opanaike — (1965) The yield recorded over the two-year cycle 1966 to 1968 do not show significant differences between the treatments tested. During the second year of the cycle there was a significant response to nitrogen up to 120 lb per acre per year. XLA5 — 3 types of nitrogen (urea, calcium ammonium nitrate and sulphate of ammonia) and 2 levels of lime on VP tea at Endane Estate, Kahawatte - (1965) ; ,. ;, The two-year, cycle has now been completed. During the first year of the cycle calcium ammonium nitrate gave higher yields than urea and sulphate of ammonia, but over the entire cycle these differences do-not reach the level of significance. Application of lime has not increased yields. XLA6 — 5 levels of nitrogen on VP tea at Endane Estate, Kahawatte — (1965) The results of the cycle 1966 to 1968 are presented in Table 22. TABLE 22 — Mean yield in lb made tea per acre per year ; during the cycle 1966 to 1968 Treatments Nitrogen 2nd Year Mean of. cycle Ob per acre per year) (made tea per acre) (%) (made tea 'per acre) (%) 0 3695 100 3659 1 100 120 4768 120 4116 113 240 5153 130 4472 122 360 5237 132 4620 126 480 4741 120 4182 114 L S D ( P = 0 .05 ) 459 12 404 11 XLA2 — 3 levels of nitrogen and 3 frequencies of application on VP tea at Hum- wella Group, Opanaike— (1965) The two-year cycle 1966 to 1968 has now been completed. There are no significant differences in yield between 240, 360 and 480 lb N per acre per year, or between the three frequencies of fertilizer application. XLA3 — 4 levels of nitrogen x 2 levels of shade on VP tea at Hunuwella Group, Opanaike—(1965) The results of the two-year cycle 1966 to 1968 are presented in Table 21. TABLE 21 —Mean yield in lb made tea per acre during the cycle 1966 to 1968 134 ANNUAL REPORT FOR 1968 Treatments Nitrogen Ob per acre per year) Yield of made tea (lb per acre per year) (%) 80 1209 100 120 1199 99 ' 160 1257 104 • . 200 1229 . 102 L S D ( P = a . 0 5 ) . 148 12 Shade 1040 100 -NoSh'ade . • 1407 135 L S D ( P = 0.05) 203 20 The^ unshaded plots, yielded 35% more than the shaded plots. This result is sigmficaiuY Thereis ho response to nitrogen applications above 80 lb per acre per year. XLA8 -T- .4. levels of nilrpgenv, 2 levels of shade on seedling tea at Hatherleigh Estate, Rakwana — (1965) The results of the two-year cycle 1966 to 1968 are shown in Table 24. TABLE 24 — Mean yields in lb made tea per acre per year over the two-year cycle (1966 to 1968) •• Treatments • (made tea per acre per year) (%) Shade" "•*". a v ; ' v i ? - V V , : 1741 " ' ' 100 N o shade 1815 104 L S D ( P = 6.05) " , • „ ' . . „ ' 2 5 5 1 5 Nitrogen (lb per acre per year) 0 1707 100 80 1824 107 160 1772 104 2 4 0 1809 106 L S D ( P = 0 .05 ) 92 5 The response to nitrogen extends up to 240 lb per acre per year.. From 360 to 480 lb N there is a significant depression in yield. A. A . C. Karunaratne XLA7 — 4 levels of nitrogen x. 4 levels of shade on seedling tea at Rayigam Estate, Ingiriya — (1965) Four levels of shade were being tested in this experiment. From the beginning of the second experimental cycle the shade trees were removed where l/3rd shade was previously provided, and the normal shade blocks were thinned to the 2/3rd shade level. At present only two shade treatments are, therefore, being tested, viz unshaded and shade (equivalent to the previous 2/3rd shade level). This alteration gives an increased replication which leads to greater precision in the comparison of the shade treatments. The results of the first year of the cycle 1967 to 1969 are presented in Table 23. TABLE 23 — Mean yields in lb made tea per acre in the first year of the cycle (1967 to 1969) ANNUAL REPORT FOR 1968 135 The difference- in yield between shaded and unshaded treatments was not significant. There was a response to nitrogen at 80 lb per acre per year but not beyond this. This experiment has now been terminated. XLA9 — 4 levels of nitrogen x 2 levels of shade on VP tea at Millakande Estate, Bulathsinhala — (1965) The yields over the first experimental cycle 1966 to 1968 are presented in Table 25. The plucking was interrupted for three months on account of a labour strike. The cycle was extended up to 26 months. ! TABLE 25 — Mean yield in lb made tea per acre per year for the period March 1966 to May 1968 Treatments Nitrogen Yields (lb per acre per year) (ib per acre per year) (%) 0 3060 100 160 3383 111 320 3694 121 480 3960 129 L S D ( f = 0 . 0 5 ) 77 3 Shade 3557 • 100 N o Shade 3492 98 L S D ( P = 0 . 0 5 ) 185 5 There was a significant yield response to nitrogen up to 480 lb N per acre per year. The difference in yield between the shaded and unshaded plots was not significant. . N . Yogaratnam XLA10 — Types of nitrogen (calcium ammonium nitrate, sulphate of ammonia and urea) on VP tea at Wellandura Estate, Kahqwatte — (1966) The yields during the first 18 months of the present cycle, July 1967 to July 1969 indicate that calcium ammonium nitrate is significantly better than urea (Table 26). The three fertilizers are being tested at the rate of 320 lb N psr acre per year. , TABLE 26 — Mean yield of made tea per acre during the first 18 months of the cycle 1967 to 1969 Types of nitrogen Yield Qb per acre per year) (%)' Sulphate of ammonia Calcium ammonium nitrate Urea 3506 3695 3453 100 105 99 L S D ( P = 0 . 0 5 ) 212 6 XL Al l — 4 levels of nitrogen x 2 frequencies of application on 6 VP clones at Balangoda Group, Bogawantalawa — (1966) , . . , As from the 18th month of this experimental cycle, 1966 to 1970, the nitrogen levels were changed to 120, 240, 360 and 480 lb per acre per year, and the yields over the 12-months period thereafter is presented in Table 27. TRI 2023 and TRI 2024 were the highest yielding clones. 136 ANNUAL REPORT FOR 1968 Clones Levels o f nitrogen Mean (%) 120 240 360 480 (clones) M T 1 8 1376 2160 3024 3318 2470 100 M T 16 1768 2439 2610 2697 2380 96 D G 39 1279 2871 2828 3242 2581 105 T R I 2025 1437 2229 2788 3848 2577 104 T R I 2023 1924 2937 3369 3009 2811 114 TRI 2024 1967 2733 2067 3202 2744 11 L S D ( P = 0 . 0 5 ) 262 11 Means ( N levels) 1642 2562 2948 3129 % 100 156 180 196 L S D ( P = 0 . 0 5 ) between mean N levels 388 between % 24 E. J. B. de Sirva XLA12 — 4 levels of nitrogen x 3 levels of shade on seedling tea at Sapumal- kande Group, Dehiowita — (1966) The pruning cycle of this experiment was extended by six months to 2 | years at the request of the Superintendent of Sapumalkande. Over the first two years of the present cycle the response to nitrogen appears to extend up to 240 Ih per acre, per year. The difference in yield between shade treatments is not-significant. The results of analysis of the data will be presented at the end of the present cycle. N . Yogaratnam XLA13 — 4 levels of nitrogen on TRI clones 2024, 2025 and 2026 at Berubeula Estate, Urubokka— (1966) The results upto the end of the first 18 months of the cycle 1966 to 1968 are presented in Table 28. . TABLE 28 — Mean yields in lb made tea per acre during first1% months of the cycle 1966 to 1968 Clones Yield (lb per acre) (%) T R I 2024 5412 100 T R I 2025 4980 92 T R I 2026 5066 94 L S D ( P = 0 .05 ) 605 11 Nitrogen (lb pre acre per year) 0 5291 100 160 4876 92 320 5204 91 480 5222 99 L S D ( P = 0 . 0 5 ) 692 13 The application of nitrogen did not increase yields; this is rather sur­ prising. J. I: H . Bandaranayake TABLE 27 — Mean yields in lb made tea per acre during the 12 months period from the \%th to 30th months of the cycle (1966 to 1970) ANNUAL REPORT FOR 1968 137 XLA15 — 4 levels of nitrogen x 4 levels of shade on seedling tea at Panilkande Estate, Deniyaya — (1966) The results at the end of 68 months of the cycle 1967 to 1969 are presented in Table 30. TABLE 30 — Mean yields in lb made tea per acre during the first 18 months of the cycle 1967 to 1969 Yield Treatments (lb per acre) (%) N o shade 2795 . . 100 GHricidia maculata 2953 : ' 106 Albizzia sp. 2925 105 Albizzia sp. + G. maculata 2920 104 L S D ( P = 0 . 0 5 ) 251 9 Nitrogen (lb per acre per year) 80 2692 100 120 3027 112 160 2897 108 200 2976 111 L S D (/> = 0 .05 ) 256 10 Beyond 120 lb N there was no significant increase in yields. J. I . H . Bandaranayake XLA16 — 4 levels of nitrogen x 2 levels of shade on VP tea at Mahendra Estate, Morawaka — (1966) XLA14— 4 levels of nitrogen x 2 levels of shade on VP tea at Ratnayaka Group, Deniyaya — (1966) The results at the end of the first year of the cycle are presented in Table 29. TABLE 29 — Mean yields.of made tea in lb per acre during the first year of the cycle Yield Treatments ( l b p e r a c r e ) (%) N o shade 8223 100 GHricidia maculata 6971 85 Nitrogen (lb per acre per year) 0 7352 100 160 7461 102 320 7761 106 480 7815 106 L S D ( P = 0 .05 ) 517 7 • ! The yields are very high. Application of nitrogen did not increase yields significantly. r J. I. H . Bandaranayake 138 ANNUAL REPORT FOR 1968 XLA17 — 4 levels of nitrogen x 2 levels of shade on VP tea at Berubeula Estate, Urubokka — (1966) The yields during the first year of the experiment February 1967 to Febru­ ary 1968 are recorded in Table 32. TABLE 32 — Mean yields in lb made tea per acre during the period February 1967 to February 1968. Treatments Nitrogen (lb per acre per year) Yield (lb per acre) • ( % ) 0 4162 100 160 4852 117 320 5022 121 480 5182 125 L S D ( P = 0 .05 ) 340 8 No-shade 4916 100 Shade 4692 95 L S D (P = 0 .05 ) 1039 21 There is no difference in yield between shade and no-shade treatments. There is a marked response to nitrogen up to 160 lb per acre per year. Above this level the response diminishes. This experiment was pruned in May 1968. J. I. H . Bandaranayake The mean yields for the first 18 months of the cycle are presented in Table 31. TABLE 31 — Mean yields in lb made tea per acre during the • first 18 months of the cycle Yield Treatments (lb per acre) (%) N o shade 6018 100 Gliricidia metadata 5991 100 L S D (/> = 0 .05 ) 654 11 Nitrogen (lb per acre per year) 0 5010 100 160 5800 116 320 6317 126 480 6862 137 L S D (P = 0 .05 ) 517 10 There is a significant increase in yield up to 480 lb N. J. I. H. Bandaranayake ANNUAL REPORT FOR 1968 1968 Experiment XLA18 •—* 3 types of nitrogen (urea, calcium ammonium nitrate and sulphate of ammonia) and 3 levels of nitrogen on TRI 2023 at Talgaswela Estate, Talgaswela — 3 randomized blocks — (1968) In this experiment three types of nitrogen fertilizers are being tested each at 480, 600 and 720 lb N per acre per year. The plucking commenced in May 1968 and the results will be presented at the end of the first year. H. D . Jayasinghe XLPH1 — Shade vs no shade on seedling tea at the Low-Country Station, Ratnapura — (1966) The results are presented in Table 33. TABLE 33 — Yield of made tea with and without shade Pre-treatment Yields after removing shade trees on yields (4 months) no-shade blocks Treatments before removing Before pruning After pruning shade (2 months) (2 years) . . . ( l b p e r a c r e ) (%) {lb per acre) (%) ( l b p e r a c r e ) (%) Shade 672 100 209 100 1734 100 N o shade 730 109 233 11 2009 116 The yields in the no-shade blocks show an increasing trend relative to the yields of the shaded blocks. N . S. Rajendram Visits, Lectures & Symposia Lectures Dr L. H. Fernando addressed the following, on various aspects of tea cultivation. 1 — Students from the Buddhist University 2 — Kelani Valley Planters' Association. Dr L. H. Fernando addressed the Low-Country Products Association of Ceylon on "Efficient use of fertilizers in low-grown tea". Dr D. T. Wettasinghe addressed the Kelani Valley and Sabaragamuwa Planters' Association on various aspects of tea cultivation. Symposia Dr L. H. Fernando and Dr D. T. Wettasinghe participated in the following symposia : 1 — Symposium on "Drought" for the Uva Planters' Association at Badulla. 2 — Symposium organized by Carson Cumberbatch & Co Ltd. on "Tea" at Colombo. 140 A N N U A L REPORT FOR 1968 Publications MACNEILL, B. H. & SABANAYAGAM, J. V. (1968). The induction of dodine tolerance in Fusarium oxysporum f. melonis: a technique applicable to the study of the bionomics of soil-borne fungal pathogens. Canad. J. Microbiol. 14, 1262-1263. SABANAYAGAM, J. V. (1968). Influence of host and non-host plants on the survival of Fusarium oxysporum f. melonis in soil. (In the press). WAIDYANATHA, U . P. D E S. (1968). Investigations with paraquat (Gramoxone) as a herbicide for weed control in low-grown tea. Tea Q. 39, 11-18. WETTASINGHE, D . T. (1968a). The use of diuron for weed control in mature low-grown tea. Tea Q. 39,119-120. WETTASINGHE, D . T. (1968b). A preliminary investigation of the effect of two plant factors on simazine toxicity. Proceedings of the Ninth British Weed Control Conference. 645-649. Reference MCWHORTER, C . G . & SHEETS, T. J . (1961). The effectiveness of five phenyl- ureas as foliar sprays and the influence of surfactants on their activity. Prov. SWC14, 54-59. REPORT ON THE MID-COUNTRY STATION Mid-Country Scientific Officer — D. Calnaido, BSc, PhD General The purchase of 56 A—OR—05 P of land, from the Hantane Investment Co. Ltd was completed on the 26th August, and further progress towards the development of the Mid-Country Station was achieved. There were no changes of staff during the year. Advisory Services The Mid-Country Scientific Officer and/or the District Advisory Officer attended meetings of the District Planters' Associations when invited. Many planters visited the Station for discussions on agronomic problems. Several groups of school children visited the Station on study tours. One hundred and sixteen visits were made to estates in connexion with advisory and extension work. Pests and diseases No serious pest problems were prevalent in the mid-country districts this year. Two instances of light infestations of Looper and Twig Caterpillars were reported from the Hewaheta District. Sporadic infestations of Tortrix, mites, cockchafer grubs, nettle grubs, brown bugs and eelworms were encounr tered. The problem of Shot-hole Borer in new clearings was fairly serious as many estates had not resorted to spraying their clearings either with the lower concentration of dieldrin or with heptachlor. * The diseases encountered were cases of Poria hypolateritia, of which 4 were in the Madulkele district, 1 in the Hunasgiriya district and 1 in the Hewa­ heta district; and 4 instances of Ustulina deusta, 2 from Hewaheta, 1 from Kegalle and 1 from the Gampola district. New clearings Many new clearings suffered from severe wilting during the unprecedented drought experienced during the early part of the year, but fortunately most clearings recovered with the onset of the monsoonal rains. In.most of these clearings the clone TRI 2024 was the most severely affected clone during the drought. Nursery The main faults in nurseryfimanagement were the selection of unsuitable soil for the nursery bags, irregular watering, frequent over-watering and over- shading. The practice of gradually exposing the full-grown nursery plants to sunlight was sometimes not adopted, because of the desire to economise on coir matting. Other unsatisfactory methods of shading and premature ferti­ lizer applications given even before 70% to 80% of the cuttings had rooted resulted in failures in nurseries. Another common fault was the practice of making holes with sticks in the soil bags to insert the cuttings. This resulted in air pockets at the base of the planted cuttings causing their death. fertilizer problems Many estates resorted to the application of 15 to 20 lb of zinc sulphate and claimed to have benefited by it. Most of the mid-country estates that had cut down the phosphorus and potassium in the fertilizer mixture, as an economy measure in the past, now apply 20 to 30 lb P 2 0 5 and 60 to 90 lb of K 8 0 per acre per annum. 141 142 ANNUAL REPORT FOR 1968 Field Experiments, Trials and Factory Experiments The following experiments were carried out with the collaboration of the respective Heads of Divisions, except the experiments in Entomology at the Mid-Country Station. Details of these experiments are given in the respective divisional reports. MW1 — Gramoxone, hand-weeding and N on seedling tea — (1966) There was no significant difference in yield between treatments during the first year of the experiment, which was the last year of the pruning cycle. The plots were pruned in October 1968, and all plots were hand, weeded. The following labour, calculated on an acreage basis, utilized for removing ferns and weed the plots, gives an indication of the efficacy of the treatments : No. of labourers per Treatments acre required W 1 (monthly weeding) 25 W 2 (unweeded since Sep. 1967) 96 G 1 (bimonthly application of Gramoxone) 35 G 2 (application of Gramoxone once in four months) 55 There was also no significant difference in the quality of made tea between the treatments. The experiment is to be continued in the next pruning cycle. MW2—Herbicides on weeds in seedling tea at Kirimetiya Estate, Galaha—(1968) The object of this observation trial was to determine the most useful chemicals for bringing the weed growth under control in a neglected tea field. The trial was located in abandoned tea overgrown with weeds. The plot size was 1/10 acre. The weed cover consisted mainly of Digitaria marginata, Drymaria cordata, Bidens sinensis, Commelina bengalensis and Erigeton suma- trensis. The woody shrubs were pulled out manually. Two herbicides, 2, 4-D and paraquat appear to be the most suitable for bringing the weed growth under control while diuron may be useful in maintai­ ning control. Further experiments on the rate, sequence and timing of these herbicides are envisaged. MW3 — Amitrole, 2, 4-D dalapon, diuron, pentachlorophenol and simazine on yield of seedling tea — 3 randomized blocks — (1968) Plots 1/50 of an acre in extent, were laid out at Field No. 7, Hantane Estate. Seven pre-treatment pluckings were done before the plots were pruned. Pre- treatment plucking will be continued for three months before treatments are given. MPH1 — Mulching of the young VP tea at the Mid-Country Station — (1966) The plots were re-mulched with the respective rates of paddy husk and Guatemala grass on 14th December 1966 and again on 18th July 1967, because the guatemaia thatch had to be replaced subsequent to decay. Nine weedings were done during the two-year period. The plants were cut across at 12 in. on 18th January 1968 and again on 6th November 1968 at 15 in. above ground level. ANNUAL REPORT FOR 1968 143 The following are the total weights of weeds from each of the treated plots and the fresh weights of primings calculated per acre are given in Table 1. TABLE 1 — Total weights of weeds from the mulch-treated and control plots and the fresh weights of pru- nings calculated per acre Type of mulch Paddy husk Guatemala grass Quantity (Tons per acre) '20 10 20 10 Fresh Wt of weeds (lb per plot) 47 : > 108 160 189 Fresh Wt of prunings (lb per acre) '. 21046 18731 .' 15485 14696 13493 4594 6328 M. K. Vythilingam Control . — • - 288 L S D > = 0 . 0 5 47 P = 0 . 01 63 P = 0 .001 87 It will be seen that very efficient weed control is obtained with paddy husk as mulch at both levels (significant at P < 0.001). The growth of the plants is superior when mulched with the higher level of either paddy husk or Guatemala grass. MN2 — Screening of clones for tolerance to the burrowing nematode—Rado- pholus similis—replicated — (1968) Recently, Radopholus similis, the burrowing nematode, has been found to infect tea in the Mid-Country. This experiment aims firstly to build up the population of Radopholus similis and subsequently to screen clones tolerant to it. Infested soils from three estates in the Mid-Country were collected, mixed and placed in four tanks, each measuring 15 ft x 5 ft x 1 ft. The susceptible clone TRI 2025 was planted in these tanks on 25th July 1968 in order to build up the nematode population, so as to enable the screening test for the different clones to be carried out. M . K. Vythilingam Vegetative Propagation These experiments were undertaken in collaboration with the Plant Phy­ siology Division and the results are presented in the report of the Plant Phy­ siology Division. MVP — Clonal testing at the Mid-Country Station — (1961) This experiment completed its second year of its second pruning cycle in October. Among the high yielding clones the second-year yield was twice that of the first year of the cycle, with clone TRI 2023 giving the highest yield of 4278 lb made tea per acre. The following clones yielded over 2500 lb made tea per acre per year: TRI 2026, 2025, 2151, DG 39, KEN 16/3, MT/BG, DN, MT(BG) 18, GMT 9 and T 5/35 (arranged in order of decreasing yield). The interchange of shade between the shaded and unshaded blocks has todate not resulted in significant yield differences. The shade is not yet fully established in the shaded plots. MVP — Clonal testing at the Mid-Country Station - (1962) The first year's plucking of the second pruning cycle of this /experiment was completed in July 1968. The yield remained relatively low. 144 ANNUAL REPORT FOR 1968 Clones (arranged in order of merit) Score D G 7 7 .25 iTGK 2 5 . 5 0 W 3 5.31 D G 5 .19 TRI 2021 4 . 1 9 D G 3 3 . 6 9 TRI 2046 3 . 5 6 E 7 / 2 7 3 . 2 5 M L 7 3 .25 TRI 2024 2 . 7 5 W 2/145 1 .44 TRI 2045 1.38 L S D at J " = 0 . 0 5 1.84 /» = 0 .01 2 . 4 8 P = 0 .001 3 . 2 9 MVP4 — Clonal testing at the Mid-Country Station — (1964) >jThe second year ,pf its jfirst jpruning cycle of 16 clones of this experiment was completed in October. Only sixof the 16 clones have yielded over 1000 lb of made tea per :acre per year; they areliPCG^, TRI 2Q24, DW 12, MO/116, H 1/58 and.QT 4/4. It (is interesting to rao^e thatlthe,plants raised from Lands- down seed yielded. 1586 lb'made tea per acre per year, unshaded, at this early stage of cultivation. MVP5 — Clonal testing at the Mid-Cowitry Station — (1965) The first year's plucking of this experiment was completed in October. The yields are relatively poor. MVP6 — Clonal testing at the Mid-Country Station — (19,66) Plucking of the five clones of this experiment commenced in November. MVP7 — Clonal testing at the Mid-Country Station — (1967) The nine clones of this experiment have completed their first year from planting. H . B . Ratnayake MVP3 — Clonal testing at the Mid-Country Station — (1963) The first three-year pruning cycle was concluded in October 1968. Three clones, TRI 2021, DG 7 and TRI 2024 yielded over 1500 lb made tea per acre per year, while four clones, W 3, DG 3, W 2/145 and E 7/27 yielded over 1200 lb per acre per year. Drought resistance of clones — on MVP3 (1963) Four observations following drought conditions were made on 12 clones of MVP3 (1963) on 30.3.66, 30.5.66, 19.9.67 and 14.2.68. Based on visual observations, marks were given to the clones, for their ability to resist drought. The analysed results are given in Table 2. TABLE 2 — The ability of 12 clones (of MVP3 — 1963) to . withstand drought conditions ANNUAL REPORT FOR 1968 145 Factory experiments These experiments are fully described in the report of the Technology Division. MT1 — Quality assessment of clones — (1966) Of the 18 clones tested during the year, MO 209, CW 21 and H 1/58 show great promise. On account of difficulties that arose in having the manufac­ tured experimental samples evaluated by a Tea Taster, these clones would have to be re-tested and evaluated again before a final assessment of quality is possible. MT4 — Plucking rounds cum'plucked unit — (1967) Pre-treatment manufactures were completed. Analysis of taster's reports indicates no significant differences between each of the experimental plots. The treatments were given in May. The experiment is in progress. MT5 — Gramoxone (and hand-weeding in combination with 2 levels of nitrogen) on made tea characteristics — (1967) The manufacturing properties of tea in plots subjected to eight weed- control treatments (in MW1) were compared and the differences were not found to be significant. There were also no significant differences in made, tea characteristics between the teas from plots receiving 100 lb and 200 lb nitro­ gen per acre per year. Gramoxone-sprayed teas were reported to be free from taint. The experimental area was pruned in October. MT6 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels and 3 levels of potash on made tea characteristics — (1967) , Pre-treatment tests were concluded and no significant differences were observed between the experimental plots. The treatment applications were done in June and October and manufacturing tests are in progress. MT7 — Age from prune on the characteristics of made tea — (1967) ! Pre-treatment manufacturing tests were concluded. The experimental plots have been divided into three groups of which the first was pruned in Octo­ ber. The second and third groups will be pruned in 1969 and 1970respectively, so that at the end of the third year (1970), the green leaf from the tea bushes, that aged in the three successive years from the prune, could be tested simul­ taneously. Manufacturing tests will begin after the tea recovers from pru-r nmg. T . A . Munasiaghe: Entomology ME1 — Ecology of Shot-hole Borer — at Hantane, Kandy — (1962) The population dynamics of Shot-hole Borer were studied. The daily aerial samplings were done by a vertical series of suction traps and terrestrial samplings were done monthly by the 'standard unit', 'entire stems' and the 'branch breakage' methods. The data for the six-year period, covering two pruning cycles, are being analysed for future publication. Relation between new wood and infestation There was a high correlation between the percentage of new wood, as measured by the number of units of new wood per 100 standard units and infestation, as measured by the number of all stages of live borers (eggs, larvae, 146 ANNUAL REPORT FOR 1968 pupae and adults, males and females) per 100 standard units (b = + 0.01493 ± 0.00358 when P < 0.05 ; r = + 0.8589). Both the quantity of hew wood and. the borer infestation increase sharply from the 9th to 12th month after the prune and reach a peak around the 18th month and then gradually decline. It is interesting to note that there is a gradual build-up of both the new wood and the infestation towards the latter half of the 3rd year or the pruning cycle, ie, 30 to 36 months after the prune. This information, in the light of the earlier findings (Calnaido & Thirugnanasuntharan 1966), provides evidence that the borer populations in the tea fields are determined mainly by the synchronous growth of new wood that arises as a result of the practice of pruning. Validity of the 'standard unit' method for borer sampling .m The. borer population in tea, as measured by the number of live borers per JOO .standard:units, was compared with the counts of all stages of live borers per 25 entire branches of tea stems and it was found that there was high correlation between the infestations as measured by the two methods of sani- plmg(b/,=,.-h,0.9813'± 0.2171 whenP < 0.05 ; r = 0.8850). This indicates that borer sampling by the 'standard unit' method (Judenko 1968) gives an excellent assessment of the borer population in tea. Relation between galleries and infestation , .The high correlation (r = + 0.9712) between the number of galleries and infestation, as measured by counts of all stages of live borers in standard units of tea stems, indicates that a mere count of the occupied galleries in standard units would give a reliable estimate of infestation. Relation between breakage of branches and the number of galleries in them There was a high correlation (r = + 0.6129, P < 0.01) between branch breakage, as estimated by the number of broken branches in tea bushes, caused by the application of light pressure on them, and the total number of galleries (occupied, vacant and healed) in standard units. This direct correlation bet­ ween, gallery formation and branch breakage, would suggest that low yields resulting frpm borer damage are mainly due to the breakage of branches. ME2—Clonal selection for shot-hole borer tolerance (on MVP1 to MVP7). —(1966) ....... The investigations on 60 clones of MVP1 (32 clones), MVP2 (16 clones) arrdMVP3 (12 clones) were completed todate. The existing list of clones of MVP1 and MVP2 where the clones are arranged in order of yield and other characteristics, viz quality, drought resistance and shot-hole Borer tolerance; was revised so as to include the clones of MVP3 and has been published (Thiru- gnanasuntheran & Calnaido 1969). A comparative study was made on the effect of shade vs none on the clones of experiments MVP1, MVP2 and MVP3 in respect of (a) shot-hole bMer infestation, as measured by the number of galleries formed and (b) the ability of the galleries to heal in the different clones as measured by the per­ centage of healed galleries in pruhings (Table 3). When all observations on the 60 clones of the three experiments were considered together, at the end of their first pruning cycle, there were no significant differences between the shaded and unshaded tea in respect of borer infestation. Clones under shade however showed significantly better healing of the galleries in tea stems:, made by.;Shot-hoIe Borer. " ..Vi:"-7 ANNUAL REPORT FOR 1968 147 TABLE 3 — The effect of shade and no shade on (a) shot-hole borer infestation and (b) the ability to healing of galleries of clones (of MVP1, MVP2 & MVP3) Treatment Experiments ( N o . of clones i n brackets) M V P 1 (32) M V P 2 (16) M V P 3 (12) M e a n of t h e . 3 e x p t s . (60) (a) N o . of shade 97 84* .. 91 92 A es -• • . • ...... (,/25 branches) n o s h a d e 78** 110 : . - , ,63 . !** . . 83 (b) % healed shade 87*** 85 79 * 8 5 V galleries n o s h a d e 81 , 87 . 78 , . 82 •,/•;.. *** = significant at P = 0 .001 y r i ** =-= significant at P = 0 . 0 1 * = significant at P = 0 . 0 5 . / • . . • : ME3 ^— Fertilizer response to shot-hole borer control at Hantane, Kandy — (1966) This experiment was concluded in September. The treatments were dieldrin (1.5 lb ai per acre) as a post-pruning spray and aldrin and heptachlor (1.5 lb ai per acre) as mid-cycle sprays together with two' levels df fertilizer; viz 80 and 160 lb nitrogen per acre per year. Yield records Were taken fort­ nightly and borer samplings were done once in every three months. All treated plots were significantly less infested with borer than the un­ treated plots. There were, however, no significant differences in infestation between the two levels of nitrogen. Analysis on yield showed no significant differences between either the : treatments' or the two levels of nitrogen. The non-significant results were most likely due to the significant block variations noticed. This experiment shows that heptachlor is as good as dieldrin and aldrin in borer control, when applied as a mid-cycle spray. ME4 — Fertilizer response to shot-hole borer control, at Bandarapola, Matale • - (1966) ' " ... This experiment was concluded in June. The treatments were dieldrin (1.5 lb ai per acre) as a post-pruning spray at two levels of fertilizer, viz 80 and 160 lb nitrogen per acre per year. Yield was recorded fortnightly and the borer samplings were done once in every three months: The treated plots were significantly less infested than the untreated plots. There was no significant difference in borer infestation between the levels of nitrogen application. There was also no significant difference in yield either in the treated plots or the plots with the two levels of nitrogen. Here again results were not significant, possibly because of the significant variations among the.blocks. . MES — Biological vs insecticidal control for Shot-hole Borer at Hantane, Kandy — (1966) This experiment was concluded in September. The treatments'were dieldrin (1.5 lb ai per acre) as a post-priming spray, aldrin and heptachlor (1.5 lb ai per acre), Baur's'C'8949 (100 g ai per acre) and Carvicron (200 g ai per acre) as mid-cycle applications and the cultural treatment of clean pruning all the decayed branches. The fungicide nickel chloride was an added t reat ment given monthly from the mid-cycle onwards, to test whether the borer 14* ANNUAL REPORT FOR 1968 could be controlled indirectly by spraying for controlling the Ambrosia fungus. All the treatments were given a higher dose of fertilizer, viz 180 lb nitrogen per acre per year. Fortnightly yields and borer samplings once in every three months were recorded. Here again the treatments did not show any signifi­ cant difference either in borer infestation or in yield, possibly because of the large block variations noticed. The percentage control of the population, as measured by a method of integration indicated that dieldrin and heptachlor gave almost the same degree of borer control. ME6 — Control of Shot-hole Borer with mid-cycle applications of Heptachlor vs clonal tolerance of borer attack at Dartry Group, Gampola — (1967) The clones in this experiment are TRI 2023, CH 13 and KEN 16/3. Bi­ monthly borer samplings are being carried out. The analysis of results up to the 30th month after the prune showed that both the treated and untreated plots of clones TRI 2023 and CH 13, and only the treated plot of KEN 15/3, were significantly less infested than the untreated plot of KEN 16/3. There was no significant difference in infestation between treated and untreated plots of clones TRI 2023 and CH 13. This experiment is in progress. K. Thirugnanasuntharan Extension Experiments XMA1 — Calcium ammonium nitrate, sulphate of ammonia and urea at 3 levels and 3 levels of potassium on seedling tea at Kellebokka Group, Madul- kele — (1966) Todate, after one year of plucking, no significant differences in yield were noted between treatments. XMA2 — Calcium ammonium nitrate, sulphate of ammonia and urea at 3 levels and 3 levels of potassium on seedling tea at Wattakelle Estate, Madul- kelle — (1966) The yields with three levels of nitrogen over a period of 12 months are given below. The differences resulting from the use of different types of nitro­ gen and levels of potassium were not significant, but the differences resulting from the use of different levels of nitrogen were significant. Levels o f nitrogen Yield ( lb per acre per year) ( lb per acre per year) 90 1774 180 1609 270 2097 L S D (P «= 0 . 0 1 ) 288 XMA3 — Calcium ammonium nitratf, sulphate of ammonia, urea each at 3 levels of nitrogen and 3 levels of potassium on seedling tea at Hantane Estate, Kandy — (1966) Pre-treatment yields were recorded from 19th November 1967. Treat­ ment application of fertilizer was given on 19th June 1968. Yield records are being maintained. It is too early to analyse the results. XMPH1 — 4 levels nitrogen and 3 levels shade on seedling tea at Kirimetiya Estate, Galaha — (1966) ANNUAL REPORT FOR 1968 149 The yield response to nitrogen application was significant at the level of 90 lb N per acre per year. Nitrogen Yield (lb per acre per year) (lb per acre per year) , 0 1073 90 1348 180 1310 270 1505 L S D ( P = 0 . 0 5 ) 246 XMPH2 — 4 levels of nitrogen and 3 levels of shade on seedling tea at Kelle- bokka Group, Madulkele — (1966) There were no significant differences between levels of shade and also between levels of nitrogen. The shade planted 18 months ago is not yet fully established. XMPH3 — 4 levels of nitrogen and 3 levels of shade on seedling tea at Mausa- galla Estate, Maduikelle — (1966) There were no significant differences between treatments after one year of plucking. XMPH4 — Shade vs no shade, Mahaousa Estate, Madulkele — (1966) After 2 1/2 years of plucking there is no significant difference in the yield of the shaded field (27 acres )and the unshaded field (32 acres) of this paired- field trial. M. K. Vythilingam Visits, Lectures & Symposia Dr D. Calnaido read a paper entitled "Pest ecology in relation to pest control strategies" at a symposium on "Crop Protection", at the 24th Annual Sessions of the Ceylon Association for the Advancement of Science. He also participated at a symposium on "Drought in relation to tea" held at the Uva Club on 29th November. Publication THIRUGNANASUNTHARAN, K. & CALNAIDO, D. (1968). Further observations on the tolerance and susceptibility of tea clones to shot-hole borer infestation. Tea Q. 39, 6-10. References CALNAIDO, D. & THIRUGNANASUNTHARAN, K. (1966). Preliminary ecological studies on Shot-hole Borer and their relation to the control of the pest. Tea Q. 37, 28-45 . JUDENKO, E. (1958). Trials with a method of assessment of infestation caused by Shot-hole Borer (Xyleborus fornicatus Eichh.) on old tea. Tea Q. 29, 51-59. REPORT OF THE UVA STATION VvaSciehtificOfficer — L M . d e W. Tillekeratne, BSc, MEd The Gonakelle Substation Activities on this station continued to be confined to clonal testing and miniature manufacture. Results obtained during the year are given in the re­ ports of the Plant Physiology and Technology Divisions. Mr T. R. B. Sally was transferred to the Low-Country Station in September. The Agratenna Substation The transfer of the selected land area to the Institute is still pending. The Agraterme Substation Cornmittee was appointed by the Board to assist them in the establishmentof the Agratenne Substation. The Committee consisted of the Chairman of the Uva Planters' Association, the TRI Board Member in the Uva Province, members p( the. Experimental and Estates Committee of the . : lRI representing the.Baduila and Bandarawela Districts, the official visitor to the Substation arid the Uva Scientific officer as Secretary. The Committee held one meeting and submitted a report on the progress of the Substation. The Subcommittee went into the question of the area of land required for this project, and on their recommendation it has been decided to purchase .-approximately. 207 acres of .land, consisting of 72 acres old tea, six acres jak clearing and 129 acres scrub jungle and patna. Unfortunately it was, difficult to obtain the services of a permanent officer to reside and look after the work on this substation and other arrangements for temporary staff had to be made. The junior staff bungalow was completed in March and was occupied by the Accounts Clerk until his transfer to Ratnapura in September. The clonal testing experiment planted in 1967 was resupplied towards the end of the year. Different clones showed various degrees of resistance to the severe drought, and in some cases the casualty rate was as high as 40%. A further five acres was replanted towards the end of the year, the replanting taking the form of an experiment in conjunction With the Agricultural Chemistry Divi­ sion. Five clones are under test, with three methods of bringing into bearing, and three levels of shade. The design is of the split plot type, with shade treatments being split on blocks, clones within the blocks, and subplots for bringing intobearing treatments. "The experiment consists of nine blocks each containing 15 plots giving"Si grand total of'135 plots. ^: Field Experiments & Trials Experiment t JPHl was concluded and results reported in the Report of the Advisory Division for 1967. UPH7 — Time of pruning, fertilizer application one month before pruning and resting three months before pruning at Telbedde Group, Badtilla — (1967) This experiment which was started in January 1967 and reported in the Annual Report for that year was concluded this year. The results are being statistically analysed except the effects on dieback caused by fertilizer applica­ tions one month before pruning which are given in Table 1. ' 150 '" ANNUAL REPORT FOR 1968 151 XUA3 — 3 types of nitrogen at 3 levels at Hugoland Estate, Uda Pussellawa — (1965) This experiment completed two years of post-treatment pluckings. None of the treatments for both types and levels of nitrogen resulted in significant differences in yield. ... - TABLE 1 — Average dieback as assessed on 25 bushes per • , plot in lb Jan. Feb . Mar. Apr. May. Jun. Jul. Aug . Sep . Oct. N o v . D e c . Fertilizer applied 3 . 4 8 3 . 7 9 2 . 9 2 3 . 4 6 3 .71 2 . 5 4 3 . 2 4 4 . 6 2 3 . 2 1 3 . 1 3 2 . 4 8 3 . 0 4 Fertilizer . notappl ied 4 . 2 4 4 . 7 4 6 . 1 4 5 . 1 5 3 . 9 6 3 . 5 0 4 . 8 7 6 . 6 0 3 . 5 3 4 . 1 2 2 . 9 2 3 . 8 5 The ' t ' test showed that the increase in dieback by applying fertilizer one month before pruning, is statistically highly significant. UVP6 — Performance of clones in soils of high acidity at Hugoland Estate, Uda Pussellawa — (1965) This trial was planted in late 1965. Plucking records and observations are being kept. UYP7 — Levels of fertilizerand clones at Mahadowa Group, Madulsima — (1966) This trial is being continued. The results have to be statistically analysed. Extension Experiments All extension experiments in Uva continued to be managed by the!staff attached to the Uva Station. Most of the experiments completed two years of post-treatment pluckings. The results obtained have been statistically analysed. ! j '\'r XUA1 — 3 types of nitrogen at 3 levels at Aislaby Estate, Bandarawela — (1965) This experiment was pruned during the year and is being continued in the new cycle. None of the treatments for both types and levels of nitrogen resulted in significant differences in yield. XUA2 — NPKeach at 3 levels and control in all combinations at Aislaby Estate, Bandarawela — (1965) This experiment completed two years of post-treatment pluckings. There was a highly significant linear response to the levels of nitrogen, (see Table 2) TABLE 2 — Yield response to nitrogen levels at Aislaby Estate, Bandarawela Nitrogen treatments Yield per acre (lb N per acre per year) (lb made tea) 120 4387 240 4725 360 4872 L S D ( P = 0 .05 ) 222 152 ANNUAL REPORT FOR 1968 XUA4 — NPK at 3 levels and control in all combinations at Hugoland Estate, Uda Pussellawa — (1965) This experiment completed two years of post-treatment pluckings. None of the treatments for types or levels of fertilizer resulted in significant differences in yield. XUA5 — 3 types of nitrogen at 3 levels at Telbedde Estate, Badulla — (1965) This experiment completed two years of post-treatment pluckings. None of the treatments for types or levels of nitrogen resulted in significant differences in yield. The experiment was discontinued after pruning. XUA6 — 3 levels of nitrogen and.3 levels of Limbux at Telbedde Estate, Badulla — (1965) This experiment completed two years of post-treatment pluckings. None of the treatments resulted in significant differences in yield. The experiment was discontinued after pruning. XUA7 — Guatemala, Mana and Napier as rehabilitation species at Telbedde Estate, Badulla — (1965) Experimental plots were planted with tea and observations on the growth of tea are being made. XUA8 — 3 types of nitrogen at 3 levels at Nayabedde Estate, Bandarawela — (1965) This experiment completed two years of post-treatment pluckings. The experiment was discontinued. XUA9 — Guatemala, Mana and Napier as rehabilitation species at Nayabedde Estate, Bandarawela — (1965) Experimental plots were planted with tea, and observations on the growth of the tea are being made. XUA10 — 3 levels of nitrogen and 3 levels of Limbux at Canavarella Group, Namunukula — (1965) This experiment completed two years of post-treatment pluckings. The results given in Table 3, indicate that there was a significant yield response to nitrogen levels. There was no significant response to levels of Limbux. TABLE 3 — Yield response to nitrogen levels at Canavarella Group, Namunukula. Treatments Yield (lb N per acre per year) (lb made tea per acre) 120 5391 240 5795 360 5924 L S D (P = 0 . 0 5 ) 249 XUA11 — 3 types N at 3 levels at Canavarella Group, Namunukula — (1965) This experiment completed two years of post-treatment plucking. The tea was pruned and the experiment is being continued in the new cycle. There was no significant yield response to types and levels of nitrogen. ANNUAL REPORT FOR 1968 153 XUA12 — NPK at 3 levels and control in all combinations at Spring Valley Group, Namunukula — (1965) The experiment completed 20 months of post-treatment pluckings. The tea was pruned and the experiment is being continued in the new cycle. The results are given in Table 4, and indicate a significant response to levels of nitro­ gen. There was no response to the other treatments. TABLE 4 — Yield response to nitrogen levels at Spring Valley Group, Namunukula Treatments Yield Gb N per acre per year) (lb made tea per acre) 120 2838 240 3060 360 3492 L S D {P = 0 .05 ) 276 XUA13 — 3 types nitrogen at 3 levels at Spring Valley Group, Namunukula — (1965) The experiment completed two years of post-treatment pluckings. The results given in Table 5, indicate the response to levels of nitrogen which was significant. There was no significant response to the different types of nitrogen. TABLE 5 — Yield response to nitrogen levels at Spring Valley Group, Namunukula Treatments Yield (lb N per acre per year) (lb made tea per acre) 120 6018 240 6300 360 6348 L S D {P = 0 .05 ) 162 XUA14 — NPK at 3 levels and control in all combinations at Kahagalla Estate, Haputale — (1966) The experiment completed 20 months of post-treatment pluckings. There were no significant yield responses to potassium and phosphorus at any level. There Was a significant response to nitrogen levels (Table 6). TABLE 6 — Yield response to nitrogen levels at Kahagalla Estate, Haputale Treatments Yield (lb N per acre per year) (lb made tea per acre) 120 3803 240 3778 360 4174 L S D (P = 0 .05 ) 192 XUA15 — 3 types of nitrogen at 3 levels at Kahagalla Estate, Haputale — (1966) The experiment completed 20 months of post-treatment pluckings. The results, given in Table 7, show the significant response to levels of nitrogen. Response to the types of nitrogen was not significant. 154 ANNUAL" REPORT FOR 1968 • : TABLE "7 — Yield response to nitrogen levels at Kahagalla- • Estate, Haputale •; • : Treatments Yield , , (lb N per acre per year) (lb made tea per acre) r ' ! : : ; ; " 1 2 0 ; :>"l::: • 3882 " 240 " 4128 ::• 360 4164 L S D ( P - 0 .05 ) 216 XUA16 —.3- levels of,N and 3 levels of Limbux at Hugplarid Estate, Uda Pussel- /aira —(1965) The experiment completed 2 years of post-treatment pluckings. The results given in Table 8 indicate that there was a significant response to the levels of nitrogen. • There was no significant response to levels of Limbux. TABLE 8 — Yield response to nitrogen levels at Hugoland Estate, Uda Pusseilawa Treatments Yield • : (lb N per acre per year) ( lb made tea per acre) , . . . 120 '5046 ' ' 240 •" " r > : 5130 . • 360 5304 L S D (P = 0 .05 ) . 195 Acknowledgements Our sincere thanks are due to the Manager, Ury ;Group and his staff for their kind co-operation, especially in obtaining permits for the replanting subsidy scheme. Our sincere thanks are also due to Mr M. Clarke for his valuable help and guidance, readily given whenever required. A special word of thanks is due to the Managers of Gonekelle, and Ury Group and :t)Mr 5taff:for.their help and guidance in running the Uva Station. . . . REPORT OF THE ADVISORY 'DIVISION •Acting Chief Advisory Officer — L. M. de W. Tillekeratne, BSC, MEd General Advisory activities of the : mid-country and low-country distxicts are-in­ cluded in the reports on the Mid-Country and Low-Country Stations respective­ ly, and are, therefore, not repeated in this report. The following staff changes took place during the year. Mr J. V. Saba­ nayagam returned from overseas training in July 1968 after obtaining a Master's Degree from Guelph University in Canada. Mr Sabanayagam operated from St Coombs on his return until he was transferred to the Low-Country Station in late December. Mr R. K. Nathaniel prpdeeded in August for a course of studies leading to a Master's Degree at Guelph University in Canada. Advisory Work Types of inquiries received from estates and other sources predominating during the year dealt with the introduction of urea as a source of nitrogen, and.the reduction of phosphates and potash in fertilizer programmes. With the withdrawal of the recommendation on the use of dieldrin for the control of Shot-hole Borer in 1967, the side effects of tortrix, twig and looper cater­ pillar damage continued to show a sharp decline in 1968. Nettle grub attack in Uva especially in the Badulla valley showed a sharp increase even during the wet weather. There were a number of inquiries from estates regarding replanting without rehabilitation and numerous visits had to be made in this connexion for purposes of soil sampling and general observations so as to = submit .reports for estates to qualify for the subsidy. Work in this connexion will increase rapidly in future. In general, the climatic conditions during the year were not conducive to high crop production. The Up Country and to some extent Uva suffered badly from the severe drought conditions during the early part of the year. This was followed by a very wet and prolonged SW monsoon in the Up Country, and one of the worst droughts experienced in Uva, which extended well into Sep­ tember. The drought in Uva appears to be the worst for over forty years" which is as far as most climatic records go. The rainfall recorded oh almost all estates in Uva shows that only half the decennial average fell within the first six months of the year, the Welimada area registering about 11.6 inches of rain up to the end of June. The low rainfall following the early drought did not allow for sufficient storage of water in the soil to see the bushes through the July to September drought, with the result that the old seedling tea, especially fields late in the pruning cycle, as well as clearings planted from 1958 to about 1965 suffered severely. The younger clearings did not suffer so badly. Blister Blight was a problem in the Up Country because of the severe and prolonged SW monsoon, and recovery of fields pruned early in the monsoon suffered a set­ back due to blister attacks. Extension Experiments The extension experiments in the Up Country on the types and levels of fertilizer continued to be managed by the Agricultural Chemistry Division. Extension experiments on shade x levels of nitrogen were managed by the Advisory Division in conjunction with the Plant Physiology Division. With the departure of Mr Nathaniel these experiments were handed over to the Plant Physiology Division. The details of these experiments are given in the Reports of the Agricultural Chemistry and Plant Physiology Divisions. 155 156 ANNUAL REPORT FOR 1968 Extension Activities Exhibitions The Institute participated in the Schools' Agricultural Exhibition in the Ratnapura District from 28th to 30th January, and also at an Agricultural Exhibition in Horana from 3rd to 5th October. Symposium A largely attended Symposium on 'Drought' was organized in conjunction with the Uva Planters' Association on the 29th November. The proceedings took the form of questioning and answering panels. Four senior planters from each of the three sub-districts in Uva comprised the questioning panels, while Heads of Research Divisions and other members of the Senior Staff of the Institute were included in the answering panels. Questions were asked and answered on all aspects of tea cultivation and manufacture with special reference to drought condtions. Public relations A number of foreign visitors were shown round the Institute, and a number of batches of school children were instructed on tea cultivation. Three officers from the Ceylon Tea Propaganda Board spent a few days at the Institute before they left Ceylon on their foreign assignments. Acknowledgements Our sincere thanks are due to the Chairman, sub-district Chairmen of the Uva Planters' Association and all members of the panels for their kind co­ operation in making the symposium on "Drought" a success. Our thanks are also due to the President, Secretary and Members of the Committee of the Uva Club for permitting the use of the Club premises to hold the symposium; to all Managers, Superintendents and Assistants of estates that have come into the extension experiment scheme for their ready co-operation during the year, and to all Heads of Divisions for their co-opera­ tion in 1968. REPORT ON ST COOMBS ESTATE Agriculturist — L. A. Seevaratnam, BSc General Mr M. R. K. Gabriel, Junior Assistant Clerk/Storekeeper left the service of the Institute on 1st March. He was not replaced during the year. Mr G. Navaratnam was transferred to St Joachim in May. The construction and maintenance of all buildings and roads as well as the maintenance of the grounds and water supply at St Coombs was placed under the charge of the Agriculturist in October. The Institute's Central VP Nursery, handed over to the Agriculturist in July, now supplies plants for both St Coombs estate plan­ ting -as well as for experiments. Acreage as at 31st December 1968 A R P Seedling tea 162 3 15 VP tea 80 2 23 Young VP tea 12 0 20 Land under rehabilitation 22 2 09 Area reserved for clonal cuttings 7 0 17 Other land (fuel clearings, buildings, roads, gardens etc) 138 0 19 423 1 23 Crop St Coombs produced an all-time record crop of 397,894 lb made tea, which exceeded the estimated crop of 364,800 lb by no less than 33,094 lb. It was the highest crop ever recorded in the history of St Coombs. There were several reasons for the record yield. The most significant of these were : 1 — A high standard of work was maintained throughout the year, and plucking rounds kept generally at five to seven days. A rea­ sonable balance was maintained between the need for a high standard of plucking, and the need to produce a good overall yield. This policy has paid good dividends in terms of profita­ bility. 2 — During 1968, 48 acres of tea completed four years from the last prune, but it was decided that this tea could be plucked economi­ cally for another year. The tea was, therefore, not pruned and contributed about 25,000 lb of made tea to the year's crop since 1st July. f 3 — The area of VP tea which came into bearing during the year, as compared with similar figures for previous years are given in Table 1, and indicates the impact of this factor on the yield of St Coombs. 157 158 ANNUAL REPORT FOR 1968 Month 1968 1967 1966 1965 1964 January 141 116 155 136 152 February 75 109 117 '88 112 March 82 106 151 97 114 April 177 140 149 183 145 May 178 187 161 . 177 147 June 173 134 132 129 168 July 100 105 138 108 77 August 136 120 147 87 112 September 169 118 123 106 95 October 181 '• 120 122 '.. .125 " • 1 1 5 November 220 •': 152 141 137 : December 181 146 127 137 117 T O T A L 1813 1553 1663 1510 1430 Total rainfall (in.) . 9 0 . 5 9 8 3 . 9 6 7 0 . 9 4 . 9 3 . 2 1 7 9 . 7 6 Ncv.of wet days 192 202 188 204 198 Average N per acre per annum (lb) 222 248 248 1 8 4 : 162 Fertilizer application The fertilizer policy was modified "from that adopted in 1967. Except in experimental areas, phosphate, potash, dolomite and borate were not applied. The dose of nitrogen was also reduced by various quantities ranging from 50 to 100 lb for different fields. Prilled urea was used as a source of nitrogen on a field scale in certain fields. Table 3 gives the yield per month for each field together with the type of nitrogen' and the quantity of fertilizer applied. ; The financial aspects of the working of St Coombs for 1968, as compared with previous years are given in Table 4. TABLE 1 — Relation between the area of VP tea coining into bearing and the total crop on St Coombs from 1964 to 1968 Year Total crop Acreage of VP tea coming into bearing 1968 397,894 13A — 2R — 01P 1967 356,036 Nil 1966 . 360,111 13A — 3R — I I P . 1965 . 336,239 Nil The yield per acre per month for St Coombs Estate from 1964 to 1968, the total rainfall, the number of wet days and the average quantity of nitrogen applied for each year are given in Table 2. TABLE 2 — Yield per acre per month for St Coombs from 1964 to 1968; total rainfall, the.number of wet., days and the average quantity of N applied for each year TABLE 3 — Monthly yields of fields from January to December 1968 Field N o . Type of nitrogen fertilizer* Total N (lb) per annum Jan. Feb. Mar. Monthly yields (lb per acre) Apr. May Jun. Jul. Aug . Sep. 1 Urea 200 175 93 57 243 181 168 123 156 159 2 S/A 200 165 53 • 34 156 112 86 62 124 96 3 — — 212 58 — '• . — '•• — 4 Urea 250 79 71 87 130 130 108 77 . 109 121 5 — — 67 25 32 110 208 35 <6\\ Urea 2 5 0 , . 114 5 9 . 47 208 91 160 97 127 222 7 S/A 250 262 I l l 108 286 323 223 198 184 239 8 S / A . 250 241 9 9 ' 76 401 221 339 130 236 295 • C A N 2 0 0 v 83 5 5 . . 53 140 140 118 87 .. . 96 132 10. S /A 200 55 84 ^ " 105 183 149 208 98 150 169 10 (clonal) C A N 250 '•• 194 9 7 ' 109 250 375 213 146: 188 219 1 l,r; .•S/A 250 158 7 2 . . . 120 225 ... 147 214 173 181 12 Urea 200 186 72 76 214 211 180 107 120 186 13 Urea 200 169 92 81 229 237 144 91 112 172 H.. . ".!: • :CAN 200: : 127 ,.-;«7:- 103 197 v 126 230 66 ; :. 126 161 1 5 ' Urea 200 ' ! ' 153 : 109 • : 87 264 •i 255 : 250 97 199 2 3 8 . 16 C A N 250 195 104 95 341 156 209 111 178 206 17 S/A •: . : : 250 227 •152 • 132 . 338 310 :• 245 , . -137 161. . 181 * C A N = Calcium a m m o n i u m nitrate S/A = Sulphate of ammonia Urea = Prilled urea 8 TABLE 4 — Working of St Coombs Estate for the year 1968 in comparison to previous years' Year Total crop (lb made tea) Yield (lb made tea per acre) N e t t sale price (cents per lb) Cost o f production (cents per lb) Estimated Actual Gross profit (Rs) T R I contribution (Rs) Actual profit (Rs) 1968 475,502»t 1813 229* 185 165* 282,115* Nil 282,115* 1967 457,727 1553 203 181 183 90,402 Nil 90,402 1966 431,697 1663 218 161 170 189,302 Nil 189,302 1965 419,338 1510 224 153 148 287,862 63,763 224,009 1964 306,717 1430 243 153 157 252,074 61,065 191,009 * Subject to verification by the Auditors f Includes 77,608 lb crop , secured o n bought leaf > Z z c > r 73 EN 8 73 H T] O 73 oo ANNUAL REPORT FOR 1968 161 Cultural Operations All fields were under fungicidal protection against Blister Blight during; both monsoons. Field No. 1 Seedling tea area V P tea area Clones planted Land under rehabilitation Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade Experiments 1 A - 3 R - 3 5 P 18A-OR-5P T R I 777, 2016, 2022, 2023, 2024, 2025, 2026 2 A - 0 R - O P 1964 and 1967 (8A) 19171b 2031 lb Prilled urea 2001b Erythrina lithosperma, Grevillea roubsta P H I ( 0 . 5 A ) , N 7 ( 0 . 2 5 A ) , N 1 5 ( 0 . 2 5 A ) , N 2 1 ( 0 . 2 5 A ) Eight acres in this field completed their fourth year from the last prune, and were continued to be plucked further. All species of Acacia on this field were removed during the year after they had been ring barked and were quite dead. In a few isolated poor areas, the VP tea succumbed to the severe drought experienced this year. Various soil conservation measures were intensified in these areas before they were replanted again with VP tea during the year. These measures included the construction of terraces in steep areas, and the removal of stones in rocky areas. The Grevillea robusta shade was thinned out by ring-barking every other tree during 1967. Felling was, however, not done as these trees were not quite dead. Field No. 2 Seedling tea V P tea area Clones planted Planting year Last pruned Yield per acre 1967 Yield per acre 1968 Type o f N Shade Experiments — N i l 7A—1R—23P — T R I 7 4 0 , 7 7 7 , 2 0 2 3 , 2 0 2 4 , 2 0 2 5 , 2 0 2 6 , 2 0 3 9 , 2 1 4 2 , D T 1, D T 9 5 & E 7 / 2 7 — 1964 — N o t pruned so far — 12391b — 1351 lb — Sulphate of ammonia (T200) — N i l — P H 3 (1 .78A) , P H 1 2 ( 0 . 5 A ) , V P 1 2 ( 0 . 2 A ) , This field also completed its fourth year from pruning this year, but was continued to be plucked further. Field No. 3 Seedling tea area Shade V P tea area 1965 planting Clone Yield per acre 1967 Yield per acre 1968 1966 planting Clones Yield per acre 1968 1967 planting Clones 1968 planting Clones 1968 planting Area Clones Land under rehabilitation Experiments 4 A - 2 R - 0 P (Experimental) N i l ; 1 0 A - 0 R - 1 5 P D T I 1021 lb 2 7 0 1 b 4 A - 2 R - 1 2 P T R I 740, 2024, 2025, 2142, 62/3 , 62/5, E 7/27; C Y 9 and K E N 16/3 1011 lb T R I 2023, 2025 and T C 9 4 A - 2 R - 1 2 P T R I 26, 2023, 2025, 2027, 2043, 2142, 62/9 , D T 1, T C 9 , N L 3/1 and K E N 16/3 Without rehabilitation but after fumigation with methyl bromide 2 A - 0 R - 2 0 P D T 1, T C 9 & T R I 2027 A l 162 ANNUAL REPORT FOR 1968 An area of 4A—2R—12P where the old tea had been uprooted in 1966 and which had been rehabilitated with Guatemala grass since then, was replanted with VP tea during the south-west monsoon. An area of 7A—OR—22P of old low-jat seedling tea was uprooted for replanting during the year. The uprooting was done using two power-operated winches, a five-ton Hessford and a ten-ton Hercules. The area was trenched after the uprooting to a depth of about two feet and most of the remaining roots were removed. Of the area uprooted an area consisting of approximately 3A—OR—20P was fumigated with methyl bromide at the rate of \ lb per 100 sq. ft and replanted without rehabilitation with grass. The balance area of 5A—OR—02P was planted with Guatemala grass. Planting of the fumigated area was done as far as possible on the contour, in blocks of 50 plants per block. The plants were spaced If ft apart in the rows and the rows were four ft apart. As an experiment, an area of about one acre was planted with potatoes in October. This area will be planted with VP tea without rehabilitation, and without fumigation during the south-west monsoon of 1969. The tea planted during 1967 was bent twice and was later cut across. It is now being gradually plucked. Field No. 4 Seedling tea area — 30A-2R-OP V P tea area — In ravines only Last pruned — 1967 Yield per acre 1967 — 8171b Yield per acre 1968 — 13551b Type of N — Prilled urea Quantity of N — 250 lb in 5 applications Shade — N i l Experiments — P H 2 5 ( 0 . 8 A ) and P 2 0 Towards the latter part of 1967 parts of this field were sprayed with dield- rin by the Entomology Division to induce an attack of Tortrix for experimental work. Following this, the whole of this field suffered from a severe attack of Tortrix early in the year. The attack was controlled in areas outside the ex­ perimental plots by spraying DDT at 4 pints per acre. A severe loss of crop over a period of two months resulted from the attack. Field No. 5 Seedling tea area — 1A-OR-38P V P tea area — 2 A - 2 R - 1 0 P Planted — 1968 C lones — T R I 2043, N L 3 /1 . K E N 16/3 and K 145 Shade — Erythrina lithosperma Old seedling tea (16A—2R—7P in extent) was uprooted during the course of the year for replanting. Uprooting was done using winches. Certain areas of this field which were steep and not accessible to tractors were uprooted manually. The uprooted areas were trenched and most of the roots were removed. An area of 1A—OR—38Pof seedling tea which was also due for uprooting was retained for experimental work by the Nematology Division. The entire uprooted area has been planted up with Guatemala and Mana grass and is due to be replanted over the next two years. A new road was cut through the field to facilitate access to experiments and to make supervision more thorough. An area of 2A—2R—10P which was uprooted during 1967 was planted this year. The planting done during the year was for experiments. ANNUAL REPORT FOR 1968 163; Field No. 6 Seedling tea area V P tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type o f N Quantity of N Shade Experiments 9 A - 0 R - 0 P O A - 1 R - 3 5 P 1966 1557 lb 1863 lb Prilled urea 250 lb Grevillea robusta An abandoned ravine comprising of OA—1R—35P was cleared, drained and planted during the course of the year. Most experiments were concluded on this field in 1968. Grevillea robusta trees which had been ring-barked earlier and which were quite dead were felled this year. Field No. 7 Seedling tea area V P tea area — 1962 planting Clones Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade 1964 planting Clones Last pruned Shade Experiments Ni l T R I 740, 777, 2023, 2024, 2025, 2 0 2 6 , 2 0 4 3 , 2 1 4 2 , 2151, D T 95, and T K 45. 1966 2417 lb 2757 lb Sulphate of ammonia 250 lb in 5 applications Ni l TRI 740, 777, 2 0 1 6 , 1 0 2 3 , 2024, 2025, 2026, 2039, 2142, D T 1, D T 95 and E 7/27 N o t pruned so far Ni l V P 2 ( 1 . 5 A ) , P 1 8 (1 A) , A 8 ( 2 . 4 A ) 6A—OR—18P acres in No. 7 Field completed four years from the time' of planting during this year. This was, however, not pruned. Field No. 8 Seedling tea area V P tea area Clones Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade Experiments Ni l 8 A - 3 R - 2 P , T R I 777, 1114, 2024, D T 1 and D T 95 2585 lb 30381b Sulphate of ammonia 250 lb in 5 applications Ni l A 8 ( 2 . 4 A ) , A 9 (1A), W l ( 0 . 8 A ) , W 2 ( 0 . 5 A ) , W 6 ( 0 . 5 A ) , V P 1 ( 1 . 7 5 A ) , V P 2 ( 1 . 5 A ) . VP11 ( 0 . 0 5 A ) and V P 1 9 ( 1 . 7 5 A ) Field No. 9 Seedling tea area VP tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity of N 1968 Shade Experiments 2 6 A (Estate plucking 15}A) Nil 1967 9541b 1349 lb Calcium ammonium nitrate 200 lb in 4 applications Grevillea robusta, Erythrina lithosperma A 2 ( 2 . 4 A ) , and A 4 ( 0 . 4 A ) , P H 2 6 ( 0 . 0 1 A ) , V P 1 0 (0 .17A) , V P 1 4 ( 0 . 0 5 A ) , W 7 ( 0 . 0 1 A ) , P 1 4 (1A), P 1 9 (7A) , P 3 1 (O.IA) , P 3 2 (7A), P 5 6 ( 0 . 3 A ) , P l l (0 .01 A) , a n d P 5 7 ( 0 . 2 A ) 164 ANNUAL REPORT FOR 1968 Field No. 10 12A-2R-OP (Estate Plucking) 1967 1212 lb 1885 lb Sulphate o f ammonia 2001b Grevillea robusta and Erythrina lithosperma 5 A - 2 R - 2 P T R I 23 , 740, 777, 2016, 2021 , 2023, 2024, 2025, 2026, 2027, K E N 16/3, N L 3/1 , T C 9 and 2043 Clonal areas constantly pruned for taking cuttings 2565 lb 2563 lb Calcium ammonium nitrate 2501b Ni l An area of OA—3R—02P in which the old tea had been uprooted earlier was fumigated with methyl bromide and completely planted during the north­ east monsoon of this year. Fumigation of this area was done using varying doses of methyl bromide ranging from \ lb to 2 lb per 100 sq. ft in order to determine quantity of fumigant required for the control of Couch grass. Testing of two different types of polythene was also done during the fumigation of this area. Planting was done as far as possible on the contour in blocks for experiments. Field No. 11 Seedling tea area VP tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type of N 1968 Quantity o f N 1968 Shade Experiments 17A-0R-OP N i l 1966 1255 lb 19041b Sulphate of ammonia 2501b N i l A16 ( 1 . 7 A ) , P H 2 2 ( 0 . 1 7 A ) , V P 1 5 This field suffered from a tea tortrix attack early in the year, as a result of dieldrin spraying by the Entomology Division. This resulted in some loss of crop. A further quarter acre of this field was uprooted by the Agricultural Chemistry Division for an experiment on rehabilitation. Field No. 12 Seedling tea area V P tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade Experiments 2 9 A - 3 R - 0 P (Estate plucking) Ni l 1965 1986 lb 1933 lb Prilled urea 2001b Ni l P H 1 3 ( 1 . 7 8 A ) , P H 2 1 ( 0 . 0 4 A ) , P 2 0 ( 0 . 0 5 A ) , P 2 0 Windbreaks around experimental plots continued to be maintained during this year. Field No. 13 Seedling tea area V P tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N Shade Experiments 1 8 A - 1 R - 0 P (Estate plucking 15A) N i l 1964 2140 lb 1799 lb Prilled urea 2 0 0 1 b N i l i A 5 ( 0 . 7 A ) , A7 ( 0 . 7 A ) , A 1 2 (1 P H 5 ( 1 . 4 4 A ) , P 2 0 & P 2 6 (1A) 7A) , A16 ( 1 . 7 A ) , Seedling tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type o f N 1968 Quantity o f N 1968 Shade V P tea area Clones Pruning Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade ANNUAL REPORT FOR 1968 165 This field completed four years from its last prune in September this year. No pruning was done and the field continued to be plucked into its fifth year. Field No. 14 Seedling tea area V P tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade Experiments 1 2 A - 2 R - 0 P In cleared ravines only 1966 1218 lb 1767 lb Calcium ammonium nitrate 2 0 0 1 b N i l VP15 , P 2 0 Nickel chloride was used on this field for blister blight control in an experiment on disease forecasting conducted by the Plant Pathology Division. Field No. 15 Seedling tea area V P tea area Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade Experiments 2 A - 1 R - 0 P Ni l 1966 2050 lb 2311 lb Prilled urea 2 0 0 1 b Grevillea robusta Nil All the Grevillea robusta trees on this field have been ring-barked, and trees which were quite dead were felled during the course of the year. Field No. 16 Seedling tea area V P tea area Clones Last pruned Yield per acre 1967 Yield per acre 1968 Type o f N Quantity o f N 1968 Shade Experiments Ni l 4 A T R I 2024 1965 2817 lb 22441b Calcium ammonium nitrate 2 5 0 1 b N i l P 2 9 ( 0 . 6 A ) , P 3 0 ( 0 . 6 A ) & P 5 8 ( 0 . 2 A ) No phosphate or potash was applied on this field for the third year since pruning ; no serious setback was noticed so far. Manufacturing experiments were conducted utilizing leaf obtained from experimental plots in this area, resulting in some loss of crop from this field. The area of 200 clones planted on this field was bent, cut across and lightly plucked in during the course of this year. This area which had been fumigated with methyl bromide; at the dose of 2 lb per 100 sq. ft for control of Couch grass showed no regrowth of Couch grass during the year. 166 ANNUAL REPORT FOR 1968 Field No. 17 Seedling tea area V P tea area Clones Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade Experiments Ni l 4 A - 3 R - 0 P T R I 777, 2024 & 2025 1965 2828 lb 2635 lb Sulphate of ammonia 2501b Ni l Ni l Acknowledgements At the end of 1967, Mr C. W. C. Mossop of Waltrim Group, Lindula ceased to overlook St Coombs. His services to St Coombs and the Institute are recorded with appreciation. Publication D E SILVA, R. L . & SEEVARATNAM, L . A. (1968). The importance of soil air for tea root growth. Tea O. 39, 42—49 REPORT ON ST JOACHIM ESTATE Superintendent — G. S. Muttettuwegama General Mr G. Navaratnam was transferred from St Coombs to St Joachim in June as Assistant Factory Officer in place of Mr R. Navaratne who was the Assis­ tant Factory Officer at St Joachim up to end of March. Mr V. Petchimuthu the Factory KP took over the estate stores from the Head Factory Officer, Mr M. S. W. Wijeratne. All other staff appointments remained unchanged. The rainfall recorded for the year was low and February was stricken with a very severe drought lasting for three continuous weeks. A minor flood was experienced in June. Work on raising the Hidellana-St Joachim PWD road above flood level continued at a very slow pace. Acreage as at 31st December 1968 A R P Seedling tea in bearing 219 0 14 VP tea in bearing 41 1 00 VP tea not in bearing SO 0 24 Land under rehabilitation 5 0 00 Nurseries 1 3 11 Other land (Paddy, buildings, roads, line-gardens, ravines and waste land, encroachments etc) 98 3 17 416 0 26 Crop An excess of 4,665 lb of made tea was recorded against the estimate of 272,000 lb for the year. The yield per acre for the year was 1,102 lb. The very fine standard of plucking (about 65 to 75% of two leaves and a bud) which was achieved in the previous year by maintaining the plucking rounds strictly every five days and by discarding all coarse leaf and even soft banji, was discontinued in September 1968. This type of fine plucking did not pay the dividends that were expected. Thereafter, the plucking rounds were maintained at five and six days, and soft banji was not discarded. A leaf standard of 45 to 50% two leaves and a bud was maintained. This changeover, immediately increased the intake per plucker. The cost of plucking was thereby reduced. The yield per acre per month for St Joachim from 1964 to 1968, the total rainfall, number of wet days and the average quantity of nitrogen applied for each year are given in Table 1. Table 2 gives the yield per acre per month for each field, together with the type and quantity of fertilizer applied. 167 ! 168 ANNUAL REPORT FOR 1968 TABLE 1 — Yield per acre per month for St Joachim from 1964 to 1968, total rainfall, number of wet days and average quantity of N applied each year Month 1968 1967 1966 1965 1964 January 119 77 92 94 117 February 48 96 103 57 70 March 107 66 104 121 115 April 83 82 126 88 109 M a y 84 92 108 100 113 June 80 70 44 101 114 July 81 72 16 91 94 August 86 82 3 102 85 September 97 77 97 101 87 October 109 107 70 116 91 November 110 125 83 110 89 December 98 119 90 110 83 1,102 1,065 936 1,191 1,167 Total rainfall (in.) 1 4 6 . 5 2 147 .06 132 .78 166 .15 185 .28 N o of wet days 229 236 222 223 208 Average N per acre per annum (lb) 148 .68 144 .20 133 .75 143 .80 140 .16 The high cost of production for the two years was the result of fine pluck­ ing which has already been mentioned earlier in this report. The cost of production in the subsequent months after the fine plucking was dispensed with, came down considerably as given below : M o n t h C O P (cents) September 166 .38 October 151.91 November 147 .73 December (final COP) 1 8 0 . 0 3 The cost of production up to end of August was 188.75 cents. Profits It would have been possible to make a good profit on St Joachim had fine plucking been discontinued at the beginning of the year and if only orthodox teas meant for the Middle East market were manufactured. During the first half of the year, mainly CTC teas were manufactured and Orthodox teas were manufactured only in the latter half. The comparative prices ob­ tained for CTC teas and Orthodox teas are given below. lb made tea sold Average nett price per lb (cents) Orthodox 195,437 175 CTC 74,095 168 TABLTi 2 — Monthly yield of fields from January to December 1968 Field N o . *Type o f nitrogen Fertilizer 1 S/A 2 S /A 3 S /A 3 A T 2 0 0 & 9 0 0 + m i x t u r e Total N (lb) per acre 110 110 110 T200 @ Joz per plant per application in 3 applications 900 mixture 4 0 lb N per acre per application in 3 applications Month ly yields ( lb per acre) Total per Jan. F e b . Mar. Apr. May Jun. Jul. Aug . Sep. Oct. N o v . D e c . acre 96 41 86 34 4 1 24 58 92 87 105 105 733 121 37 98 77 41 — 26 61 76 95 93 104 829 90 44 102 69 90 99 96 87 88 94 85 59 1,003 80 21 93 99 78 120 128 158 109 177 167 158 1,388 4 S/A 147 144 65 138 110 146 158 174 131 140 159 150 128 1,643 5 S/A 147 106 46 101 83 97 105 124 106 94 115 9 6 84 1,157 6 S /A 147 105 37 110 97 104 42 — 29 77 85 88 95 869 7 C A N & S/A 166 157 72 93 114 97 115 113 112 121 101 130 92 1,317 8 — — Old tea uprooted for replanting 9 T200 @ \ } oz'per plant — — — — 98 181 128 123 81 139 121 78 949 10A 900 mixture 200 117 29 188 60 120 125 27 17 24 96 107 116 1,026 10B 900 mixture 200 157 4 0 161 88 168 182 152 138 122 193 180 156 1,737 > •z 2 C > r js m -d O H T| o 90 S O O S oo S/A — Sulphate of ammonia C A N — Calcium ammonium nitrate + 900 mixture is composed of Sulphate of amnion i a 2 0 . 6 % Saphosphosphate 2 7 . 5 % Muriate o f potash 6 0 . 0 0 % 700 Parts 100 100 a s S O 900 • o The financial aspects of the working of St Joachim for 1968 as compared with previous years are given in Tabic 3. > TABLE 3 — Working of St Joachim Estate for the year 1968 in comparison with previous years |p a > r 73 m -o O 73 H o 7i vo OV OO Year T o t a l c r o p (lb m a d e ten) Yie ld (lb m a d e tea per acre) N e t t sale price (cents per lb) Cos t of p r o d u c t i o n (cents per lb) Es t imated Ac tua l G r o s s profi t (Rs) T R I c o n t r i b u t i o n (Rs) Ac tua l profit (Rs) 1968 276,665* 1102 173* 193 180* — 26,152* Ni l — 26,152* 1967 272,907 1065 161 148 180 — 60,869 Ni l — 60,869 1966 251,457 936 145 160 175 —118,651 Nil —118,651 1965 331,974 1191 168 152 41 + 77,381 7,911 + 69,470 1964 — 1167 — — — — 47,955 Ni l — 47,955 * Subject t o verification by the A u d i t o r s A N N U A L R E P O R T FOR 1968 171 Cultural Operations I It was possible to complete all cultivation work according to the pro­ gramme laid out. | Field No. 1 Seedling tea area (infilled with VP Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity of N 1968 Shade Weeding Experiments tea) — 40A . .! — April 1968 — 1.205 1b 1 — 733 lb — Sulphate of ammonia — 110 lb per acre in 3 applications J — N o shade, except in 6 acres retained for ex­ perimental work — Gramoxone spraying in 30A 'done in January and March—Diuron spraying in 30A done in May, August , October & December—Contract (hand weeding) 10A done monthly From November . 6A were done by the research section — L A 3 ( 2 . 5 0 A ) ; L W 2 2 ( 0 . 6 A ) ; L W 2 3 ( 0 . 0 6 A ) ; LW25 ( 0 . 0 7 A ) ; L P H 5 ( 0 . 5 A ) Zinc sulphate was applied as a foliar spray in September and December at 5 lb per acre per round. Recovery after pruning was not good. This field had not recovered fully from the effects of the drought in February by the time the pruning commenced. Field No. 2 Seedling tea area (infilled with VP tea) Last pruned Yield per acre — 1967 Yield per acre — 1968 Type of N Quantity N — 1968 S h a d e Weed ing Exper imen t s 2 8 A - 1 R - 0 P May, 1968 1,2381b 8291b ( Sulphate of ammonia 1 110 lb per acre in 3 applications Nil I Gramoxone spraying in 26 iA | ' in February and Apri l—Diuron spraying in 26£A done in June, August, October, and Decem­ ber—Contract (Hand weeding) 2A done monthly L W 1 2 ( 1 . 2 A ) ; L W 1 3 ( 0 . 8 A ) ; L W 1 7 (0 .004A) . Zinc sulphate was applied as a foliar spray in March, September and December at 5 lb per acre per round. Recovery after pruning was good. Field No. 3 Seedling tea area (infilled with VP tea) Last pruned Yield per acre — 1967 Yield per acre — 1968 Type of N Quantitv of N — 1968 Shade Weeding 20A-1R-OP May. 1967 698 lb ! 1,003 lb Sulphate of ammonia 1 110 lb per acre in 3 applications Ni l Gramoxone spraying in 20£A in January and March—Diuron spraying in 2 0 j A done in May, August,; October and December ! LA7 ( 0 . 5 A ) ; LA8 ( 0 . 1 3 A ) ; LA9 ( 0 . 8 7 A ) LA18 ( 0 . 1 4 A ) ; LA34 ( 0 . 7 3 A ) ; L W 1 6 ( 0 . 2 5 A ) ; LW18 (0 .2A) ; ; L V P 7 ( 0 . 7 5 A ) Zinc sulphate was applied as a foliar spray in October and December. The uprooting of old tea in an area 13A 2R 23P of this field was commenced with in October/November for replanting in 1969. J Exper imen t s 172 ANNUAL REPORT FOR 1968 New clearings Both clearings were on old tea land Field No. 3A Seedling tea area V P tea area Planted — Ni l — 9 A - 1 R - 0 P — 1966 This clearing made very satisfactory progress and was gradually brought into bearing from January, the yield per acre being 1,388 lb. Fertilizer applied was T200 mixture in the first half of the year at the rate of f oz per plant per application in three applications and 900 mixture in the second half at 250 lb of the mixture per acre per application in three applications. Field No. 3B — Planted in 1967 Seedling tea area V P tea area Planted 1 A - 2 R - 3 2 P 1 8 A - 3 R - 0 8 P 1967 This clearing has made very satisfactory progress and 15$ acres were brought into bearing in November, the yield for November and December being 81 lb per acre. The fertilizer applied was T200 mixture at f oz per plant given in six applications. Filed No. 4 Seedling tea area (infilled with VP tea) Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity o f N 1968 Shade Weeding Experiments 2 8 A - 1 R - 0 P June, 1967 9 4 0 1 b 16431b Sulphate of ammonia 147 lb per acre in four applications Ni l Gramoxone spraying done in 28£A in February and April — Diuron spraying done in 28JA in June, August , October and December LA17 ( 0 . 6 8 A ) ; L W 5 ( 0 . 9 2 A ) ; L P H 4 ( 0 . 6 A) Zinz sulphate was applied as a foliar spray in March, June, September and December at the rate of 5 lb per acre per round. Field No. 5 Seedling tea area (infilled with VP tea) Last pruned Yield per acre 1967 Yield per acre 1968 Type o f N Quantity o f N 1968 Shade Weeding Experiment 3 5 A - 1 R - 0 P April , 1967 666 lb 1,157 lb Sulphate of ammonia 147 lb per acre in 4 applications N i l Gramoxone spraying done in 29JA in January and March—Diuron spraying done in May, July, September & N o v e m ­ ber—Contract (Hand weeding) 6 A done monthly LAS (1A) Zinc sulphate was applied as a foliar spray in March, June, September and December at the rate of 5 lb per acre per round. ANNUAL REPORT FOR 1968 173 Field No. 6 Seedling tea area (infilled with VP tea) Last pruned — Yield per acre — 1967 — Yield per acre — 1968 — Type of N — Quantity o f N 1968 — Shade — Weeding — Experiments 29A-3R-OP June, 1968 1,391 lb 8691b Sulphate of ammonia 147 lb per acre in 4 applications Ni l Gramoxone spraying done in 20JA in February and Apri l—Diuron spraying done, in 2 0 J A in June, August , N o v e m b e r — Contract (hand weeding) done monthly Ni l Zinc sulphate was applied as a foliar spray in March, September and December at 5 lb per acre per round. Recovery after pruning was good. Field No. 7 Seedling tea area (infilled with VP tea) — Last pruned — Yield per acre — 1967 — Yield per acre — 1968 — Type of N — Quantity of N — 1968 — Shade — Weeding — Experiments — 4 2 A - 1 R - 0 P September, 1966 1,4971b 1,3171b Calcium ammonium nitrate and sulphate o f ammonia 166 lb per acre in 4 applications vide remarks given below The weeding of the entire field was done by the research section X L P H 1 (42JA); L W 2 4 ( 0 . 5 A ) I Zinc sulphate was applied as a foliar spray in March, June, September and December at the rate of 5 lb per acre per round. This field has been divided into six blocks. In three of" these blocks the shade trees (Gliricidia maculata) have been retained and in the other three blocks they have been up­ rooted. This field received three applications of CAN at 200 lb per acre per application and one application of sulphate of ammonia at 200 lb per acre. The application of sulphate of ammonia had to be given because of the non­ availability of calcium ammonium nitrate in the market. Field No. 8 Replanted in 1968 Seedling tea area — Nil V P tea area — 4 2 A - 0 R - 0 P This clearing has made satisfactory progress and has been planted put with the following clones. Fertilizer applied was T200 mixture at the rate of \ oz per plant per application, given in three applications. Clone No. of plants TRI 2023 98,556 TRI 2025 81,144 TRI 2026 52,146 CW 21 972 232,818 174 ANNUAL REPORT FOR 1968 Seedling tea area VP tea area Date of planting Nil 3 A - 2 R - 3 2 P 1966 The tea in this clearing was planted in old rubber land and was gradually brought into bearing from June. Fertilizer applied was T200 mixture at | oz per plant bimonthly, the yield per acre being 949 lb. Field No. 10A Seedling tea area VP tea area Planted Last pruned Yield per acre — 1967 Yield per acre — 1968 Type of N Quantity of N — 1968 Shade Weeding Experiments Ni l 10A 1964 June, 1968 925 lb 1,026 lb Sulphate of ammonia 200 lb per acre in 5 applications Ni l Hand weeding done monthly LA14 ( 0 . 4 7 A ) ; LA11 ( 0 . 7 A ) ; L V P 6 ( 0 . 8 A ) Zinc sulphate was applied as foliar spray in March, September and Decem­ ber at 5 lb per acre per round. The fertilizer applied was 900 mixture. Field No. 10B Seedling tea area VP tea area Planted Last pruned Yield per acre 1967 Yield per acre 1968 Type of N Quantity of N — 1968 Shade Weeding Ni l 6A-2R-OP 1965 March 1967 at 14" 656 lb 1,737 lb Sulphate of ammonia 200 lb per acre in 5 applications Ni l Hand weeding done monthly Zinc sulphate was applied as a foliar spray in March, June, September and December at 5 lb per acre per round. The fertilizer applied was 900 mixture. Pests & Diseases There were no major outbreaks of any pest or disease. Even the very mild attacks of Blister Blight which occur normally along boundaries with over-hanging trees during November and December were not noticed. Factory CTC manufacture which started on a commercial scale at the end of 1967 was discontinued with in June after poor prices were realised for this type of tea. No new machinery was installed in the factory during the year. Experiments — LA36 (0.5A) and LW20 (0.2A) Field No. 9 METEOROLOGICAL OBSERVATIONS—1968 THE TEA RESEARCH INSTITUTE OF CEYLON. ST COOMBS. TALAWAKELE T E M P E R A T U R E S C F ) R E L A T I V E S U N S H I N E R A I N F A L L R A I N Y D A Y S H U M I D I T Y & & s | £ Q Q a .1 T* E a t/i 1_ V. • GIN >> ff . fr om 'e (2 5 yr s S S S as ,** Q < C 5 < Q Q < J a n u a r y . . . 7 6 . 0 7 2 . 5 4 4 . 0 4 3 . 5 4 0 . 5 64 96 8 .18 + 1.55 2 . 1 2 — 0 . 9 9 8 — 2 . 0 8 Februa ry . . . 8 0 . 0 7 5 . 5 4 2 . 5 3 7 . 0 3 6 . 5 40 58 9 . 0 0 + 1.84 1.93 — 0 . 5 6 2 — 5 . 3 2 M a r c h . . . 7 9 . 5 7 8 . 0 4 4 . 5 4 2 . 5 3 9 . 5 53 85 5 . 7 7 — 1 . 8 5 4 . 2 5 — 0 . 4 9 10 — 1 .60 Apri l . . . 8 0 . 5 7 6 . 0 4 9 . 5 4 7 . 5 4 3 . 0 34 83 6 . 2 7 — 0 . 4 5 6 . 0 7 — 0 . 7 4 16 — 0 . 9 6 May . . . 7 8 . 5 7 6 . 0 4 7 . 5 4 6 . 5 4 4 . 5 59 93 8 .00 + 2 . 6 5 8 . 9 4 — 0 . 5 9 11 — 7 . 9 0 June . . . 7 7 . 5 6 9 . 0 5 7 . 5 5 6 . 0 5 4 . 5 63 91 2 . 8 3 — 0 . 6 8 12 .71 + 0 . 0 9 26 + 1 .84 July . . . 7 3 . 5 6 6 . 5 5 7 . 5 5 6 . 5 5 2 . 0 69 100 2 . 7 0 — 0 . 7 2 18 .16 + 7 . 4 8 27 + 1 .86 Augus t >, . . . 7 4 . 0 6 7 . 0 5 7 . 0 5 7 . 0 5 4 . 0 .66 94 :. 3 . 5 2 — 0 . 0 5 1 3 . 2 0 + 4 . 0 6 24 — 0 . 3 6 September . . . . 7 5 . 0 6 8 . 5 5 2 . 5 5 2 . 5 4 9 . 5 [ 5 8 100 2 . 2 8 — 2 . 1 5 1 3 . 9 9 + 5 . 2 9 25 + 0 . 6 4 O i t o b e r . . . 8 6 . 0 7 1 . 5 5 1 . 5 5 1 . 5 4 7 . 5 ' 35 74 4 . 4 7 — 0 . 3 9 1 1 . 0 7 + 1.12 25 + 3 . 4 0 N o v e m b e r . . . 7 9 . 0 7 0 . 0 5 1 . 5 5 1 . 5 4 6 . 5 53 97 6 . 3 0 + 0 . 8 3 4 . 7 2 — 3 . 1 9 18 — 1.48 December . . . 7 8 . 5 6 8 . 5 4 1 . 5 4 1 . 5 3 7 . 0 52 64 6 . 1 0 + 0 . 8 6 3 . 9 0 — 1 . 9 0 14 — 1.80 7 8 . 2 7 1 . 6 5 0 . 2 4 8 . 6 4 5 . 4 —- •• . — 5 . 4 5 + 0 : 12 1 0 1 . 0 6 + 9 .5S 206 — 1 3 . 7 6 > z z c > 73 m "T3 O 73 •n O 73 o s • GO M E A N S T O T A L S ^ 4 METEOROLOGICAL OBSERVATIONS—1968 THE TRI LOW-COUNTRY STATION, ST JOACHIM, RATNAPURA R E L A T I V E S U N - R A I N Y T E M P E R A T U R E °F H U M I D I T Y S H I N E R A D I A T I O N R A I N F A L L D A Y } >> C/l (/I rt E 2 E 3 a a O E A> 1 £ m i— M O N T H i mum £ 9 g | E i S 3 .S n 3 * 3 O \-o. • o JC u s s S 's s fil £ 5 2 8. c January . 8 9 . 8 7 8 . 2 6 8 . 4 6 7 . 0 6 6 . 7 5 7 . 6 9 3 . 0 7 . 2 0 154 .7 4 . 6 0 12 February . 9 3 . 7 7 8 . 0 6 7 . 1 6 5 . 7 6 1 . 0 4 7 . 6 9 2 . 7 9 . 0 0 1 5 4 . 3 4 . 0 6 7 March . 9 2 . 4 8 0 . 2 7 1 . 6 7 0 . 4 6 9 . 0 5 7 . 3 9 4 . 2 5 . 5 0 1 5 5 . 6 8 . 8 9 19 April . 9 1 . 9 8 1 . 3 7 1 . 7 7 0 . 6 6 9 . 6 6 1 . 8 9 4 . 4 6 . 1 0 1 5 5 . 9 9 . 8 7 18 May . 9 1 . 8 78^6 7 2 . 5 7 0 . 9 6 8 . 7 6 1 . 6 9 2 . 1 7 . 1 2 1 5 4 . 9 1 5 . 0 0 18 June . 87 J 7 9 . 6 7 2 . 4 7 1 . 1 6 9 . 7 7 1 . 6 9 4 . 1 3 .41 1 4 7 . 4 3 1 . 2 3 26 July . 85^6 7 8 . 3 7 2 . 1 7 0 . 6 7 0 . 0 7 1 . 3 9 3 . 1 3 . 6 0 1 4 4 . 2 1 7 . 1 9 26 August . 8 7 . 4 7 8 . 8 7 2 . 5 7 1 . 0 7 1 . 4 6 6 . 9 9 3 . 3 5 . 9 3 150 .3 8 . 5 9 26 September . 8 5 . 9 7 8 . 9 7 2 . 1 7 0 . 5 7 0 . 8 7 2 . 7 9 2 . 5 3 . 6 4 1 5 0 . 0 1 7 . 7 0 26 October . 8 8 . 7 7 9 . 6 7 2 . 3 7 0 . 6 7 0 . 9 6 5 . 9 9 2 . 6 4 . 9 6 1 5 3 . 6 1 4 . 1 2 25 November . 8 8 . 8 7 9 . 2 7 2 . 0 7 0 . 1 7 0 . 5 6 4 . 5 9 1 . 1 4 . 9 2 1 5 2 . 7 10 .13 17 December . 8 8 . 9 7 8 . 9 7 1 . 1 6 9 . 2 6 8 . 3 6 2 . 9 9 0 . 3 5 . 0 0 1 5 4 . 4 8 . 2 3 13 8 9 . 3 7 9 . 1 7 1 . 3 6 9 . 8 6 8 . 9 6 3 . 5 9 2 . 8 5 . 5 3 152 .3 149 .61 233 > z z c > !» W T> O ?5 H T] O 73 so Os M E A N S T O T A L METEOROLOGICAL OBSERVATIONS—1968 THE TRI MID-COUNTRY STATION, KANDY T E M P E R A T U R E °F S U N S H I N E R A I N F A L L R A I N Y D A Y S & E o ^ O H Q a <{= ^ M O N T H m u m uin u 3 O §8, ren ce ge (2 r en ce ge (2 « '3 • §•« iffe i er a O •8 if fe er a >> to iff e er a > s 2 OS & Q £ a O S z January 7 4 . 4 6 5 . 5 7 . 1 + 0 . 6 2 . 7 — 2 . 0 6 — 5 c > February 7 6 . 8 6 5 . 0 9 . 5 + 2 . 3 1 .1 — 2 . 8 2 — 6 r March 7 6 . 7 6 9 . 8 5 . 9 — 1 . 3 6 . 7 + 2 . 0 11 + 2 79 w "0 April 7 9 . 5 6 8 . 4 6 . 8 — 0 . 4 1 .8 + 3 . 1 8 — 8 O 50 M a y 8 0 . 1 6 8 . 7 . 7 . 8 — 0 . 7 2 . 6 — 4 . 8 6 — 9 June 7 0 . 5 6 8 . 9 5 . 3 — 1 . 1 1 0 . 0 + 2 . 4 20 0 o July 7 0 . 3 6 7 . 5 3 . 9 — 2 . 2 1 4 . 3 + 6 . 9 2 0 0 58 August 7 0 . 7 6 6 . 9 6 . 5 + 0 . 6 5 . 0 — 0 . 4 18 — 1 VO OO September 7 0 . 3 6 7 . 3 4 . 6 — 1 . 4 8 . 2 + 1 . 9 23 + js October 7 0 . 3 6 8 . 1 5 . 4 — 0 . 5 9 . 5 — 3 . 5 20 0 November 6 8 . 7 6 6 . 4 6 . 5 + 0 . 9 1 3 . 1 + 1 .7 13 _ • 6 December 6 9 . 4 6 7 . 1 5 . 7 + 0 . 7 9 . 5 + 1 . 6 15 — 1 7 3 . 1 6 7 . 5 6 . 2 — 0 . 1 9 4 . 5 + 6 . 1 162 — 2 8 • M E A N S T O T A L S METEOROLOGICAL OBSERVATIONS—1968 THE TRI UVA STATION, DEBEDDE T E M P E R A T U R E °] >, Q o M O N T H § s a s a § B . >< a 5 s January . . . 7 5 . 4 7 1 . 5 6 1 . 6 February . . . 7 6 . 2 7 1 . 9 6 1 . 3 March . . . 7 6 . 0 7 1 . 0 6 4 . 0 April . . . 7 5 . 8 7 1 . 4 6 2 . 3 May . . . 7 8 . 0 7 3 . 0 6 8 . 7 June . . . 7 9 . 7 7 2 . 8 6 7 . 3 July . . . 7 7 . 2 7 1 . 0 6 5 . 2 August • . . . 8 1 . 1 7 3 . 6 6 4 . 4 September . . . 7 9 . 3 7 0 . 6 6 4 . 6 October . . . 7 8 . 0 7 1 . 3 6 5 . 0 November . . . 7 4 . 4 6 9 . 4 6 3 . 4 December 7 3 . 4 6 9 . 3 6 2 . 8 S U N S H I N E R A I N F A L L 1 S o iU M in im um V M ea n hr . pe r da y D iff er en ce 1 A ve . (2 5 yn In ch es D if fe re nc e 1 A ve . (2 5 yn 5 8 . 9 3 . 1 — 0 . 9 3 . 4 — 5 . 8 5 7 . 2 6 . 1 • + 1 . 5 0 . 4 — 5 . 9 6 1 . 0 3 . 1 — 2 . 8 6 . 8 — 0 . 3 5 9 . 0 4 . 0 + 1 .9 6 . 6 — 4 . 2 6 3 . 2 6 . 0 + 2 . 6 3 . 5 — 2 . 5 6 3 . 0 4 . 0 — 3 . 6 3 . 3 + 0 . 9 6 2 . 1 3 . 0 — 5 . 7 0 . 5 — 3 . 6 6 0 . 7 7 ; 0 + 4 . 8 0 . 9 — 5 . 1 6 0 . 8 3 . 0 — 1 . 5 7 . 1 + 1 .8 6 1 . 8 3 . 1 + 0 . 6 1 3 . 7 + 2 . 7 6 0 . 2 3 . 1 + 2 . 1 7 . 4 — 4 . 6 6 9 . 3 4 . 0 + 3 . 0 8 . 5 6 2 . 5 — 6 . 9 — 3 0 . 3 FIELD EXPERIMENTS TRIALS AND FACTORY EXPEREMENTS CONDUCTED BY THE TEA RESEACH INSTITUTE OF CEYLON IN 1968 All field and factory experiments carried out by the TRI in 1968, at St Coombs, St Joachim the TRI Stations at Debedde, Kandy and Kottawa, and on other estates are listed below. The following letters indicate the nature of the experiment: A — Agricultural Chemistry and Agronomy VP — Plant Propagation PH — Plant Physiology P — Plant Pathology N — Neonatology E — Entomology B — Biochemistry T — Technology S — Statistics w — Experiments on weeds and herbicides X — Extension experiments Experiments on St Coombs and other estates in Dickoya, Dimbula, Nuwa­ ra Eliya and elsewhere will have no additional letters, if they are supervised by officers of the TRI at St Coombs. The centre from which each experiment is supervised is indicated by a preceding letter as follows : L — Low Country (The Low-Country Station, St Joachim, Ratna- pura, the Kottawa Substation and estates in the low country) M — Mid-Country (The Mid-Country Station, Kandy, and mid- country estates in the Central Province) U — Uva (The Uva Station, Debedde, and estates in the Uva Pro­ vince) An extension experiment in Plant Physiology at the Uva Station for example, will have the letters XUPH, or an Agronomy experiment at St Joa­ chim will carry letters LA. For further details of the experiments, refer Part 2 of the Annual Reports of the TRI for 1965, 1966, and 1967. 179 180 A N N U A L R E P O R T F O R i$68 REFERENCE TO EXPERIMENT NUMBERS IN PART II OF ANNUAL REPORTS SERIES E X P E R I M E N T N U M B E R Y E A R SERIES E X P E R I M E N T N U M B E R Y E A R A 1 — 1 0 1 9 6 5 N • 1 — 1 1 1 9 6 5 1 1 — 1 3 1 9 6 6 1 2 — 1 6 1 9 6 6 1 4 — 1 6 1 9 6 7 1 7 — 2 4 1 9 6 7 1 7 — 2 2 1 9 6 8 2 5 — 3 2 1 9 6 8 LA 1 — 1 7 1 9 6 5 LN 1 1 9 6 5 1 8 — 3 2 1 ,966 2 1 9 6 6 3 3 — 3 4 1 9 6 7 M N 1 1 9 6 6 3 5 — 3 6 1 9 6 8 2 1 9 6 8 M A 1 1 9 6 6 U N 1 1 9 6 6 U A 1 1 9 6 5 E ; 1 1 9 6 5 A y r 1 — 1 3 1 9 6 5 2 5 — 4 0 1 9 6 6 1 4 — 2 0 1 9 6 6 4 1 — 5 6 1 9 6 7 2 1 — 2 3 1 9 6 7 5 7 — 7 1 1 9 6 8 L A J T 1 — 2 1 9 6 5 M E 1 1 9 6 5 W 1 1 9 6 5 2 — 5 1 9 6 6 2 — 1 0 1 9 6 6 6 1 9 6 7 1 1 — 1 4 1 9 6 8 B 1 1 9 6 5 L W 1 — 5 1 9 6 5 T 1 — 1 7 1 9 6 5 6 — 8 1 9 6 6 1 8 — 2 5 1 9 6 6 9 — 1 8 1 9 6 7 2 6 — 3 2 1 9 6 7 1 9 — 3 1 1 9 6 8 3 3 — 3 6 1 9 6 8 M W 1 1 9 6 6 LT 1 — 3 1 9 6 6 2 — 3 1 9 6 8 4 — 8 1 9 6 7 V P 1 — 1 6 1 9 6 5 9 — 1 1 1 9 6 8 1 7 1 9 6 6 M T 1 — 3 1 9 6 6 1 8 — 2 1 1 9 6 7 4 — 7 1 9 6 7 2 2 — 2 4 1 9 6 8 U T 1 — 3 1 9 6 6 L V P 1 — . 7 1 9 6 5 4 1 9 6 7 8 — 1 0 1 9 6 6 M V P 1 — 5 1 9 6 5 6 1 9 6 6 Extension Experiments 7 1 9 6 7 XA 1 — 5 1 9 6 5 U V P 1 — 7 1 9 6 5 6 — 8 1 9 6 6 P H 1 — 1 9 1 9 6 5 XLA 1 — 1 7 1 9 6 6 2 0 — 2 8 1 9 6 7 1 8 1 9 6 8 L P H 1 1 9 6 5 X M A 1 — 3 1 9 6 6 2 — 3 1 9 6 6 X U A I — 1 3 1 9 6 5 4 1 9 6 7 1 4 — 1 5 1 9 6 6 5 1 9 6 8 X P H 1 — 4 1 9 6 5 M P H 1 1 9 6 5 5 — 1 2 1 9 6 6 U P H 1 — 6 1 9 6 5 X L P H 1 1 9 6 5 P 1 — . 2 4 1 9 6 5 X M P H 1 — 3 , 1 9 6 6 2 5 — 5 4 1 9 6 6 X P 1 — 7 1 9 6 5 5 5 — 6 9 1 9 6 7 X U P 1 — 2 1 9 6 5 7 0 — 8 2 1 9 6 8 X E 1 — 8 1 9 6 7 L P 1 — 6 " 1 9 6 5 / X L E 1 — 7 1 9 6 5 U P 1 — 8 1 9 6 5 9 1 9 6 6 _~ ' ANNUAL REPORT FOR 1968 m INDEX TO 1968 EXPERIMENTS This list is complete upto 31.12.68 PAGE A17 — 3 levels of urea and 3 methods of application on VP tea at No. 8 and No. 16 Fields 27 A18 — Guatemala Grass (Tripsacum laxum), Mana Grass (Cym- bopogon confertiflorus and Crotolaria anagyroides), each at 3 levels of nitrogen as soil rehabilitation crops at No. 5 Field 29 A19 — Rehabilitation vs none at No. 3 Field 29 A20 — Mulching on young tea at No. 3 Field (AYT22) 30 A21 — Sulphate of ammonia, calcium ammonium nitrate and urea on 3 clones (AIT23) 31 A22 — Damage t© tea leaves resulting from foliar applications of urea 27 LA35 — Levels of nitrogen, phosphorus, potassium and magne­ sium on young plants of TRI 2023 in pots 124 LA36 — 3 levels of nitrogen on 4 clones at the Low-Country Sta­ tion, Ratnapura 125 W l l — Levels of surfactant on the herbicidal activity of diuron 31 W12 — Amitrole T and Gramoxone on Panicum repens 32 W13 — Gramoxone and diuron separately and in combination on weeds in VP tea areas . 32 W14 — Diuron, simazine and Gramoxone on weeds in VP tea areas 33 LW19 — Control of a very dense stand of Paspalum conjugatum in tea 128 LW20 — Simazine, diuron, fiuometuron and pentachlorophenol on the growth of young tea (Clone TRI 2023) 127 LW21 — Evaluation of herbicides 128 LW22 — Evaluation of herbicides 128 LW23 — Diuron for weed control in mature tea 129 LW24 — Diuron for weed control in shaded and unshaded mature tea 129 LW25 — Control of Paspalum conjugatum 129 LW26 — Herbarium of weeds 132 LW27 — Paraquat on budbreak in pruned tea 132 LW28 — Formulation of diuron 132 MW2 — Herbicides on weeds in seedling tea at Kirimetiya Estate, Galaha : 142 MW3 — Amitrole, 2, 4-D dalapon, diuron, pentachlorophenol and simazine on yield of seedling tea 142 VP22 — Panasand and Panacide for the control of mosses 52 VP23 — Gibberellic acid applications on tea cuttings , 52 VP24 — The influence of nodal position of a cutting on its rooting 52 LPH5 — Plucking lungs on recovery from pruning and yield of seedling tea at the Low-Country Station, Ratnapura 126 P70 — 3 fungicides for the control of Phomopsis theae on Clone DG.39 at Delmar Estate, Halgranoya 63 P71 — 3 fungicides for the control of P. theae on Clones TRI ' 2022 and TRI 2026 at Craig Estate, Bandarawela 64 P72 — 3 fungicides for the control of P. theae on Clone TRI 2026 at Liddesdale Group, Halgranoya 64 P73 — 3 fungicides for the control of P.theae on Clone DG 39 at Gordon Estate, Udapussellawa 64 P74' — 3 fungicides for the control of P.theae on Clone SJ 76 at Park Group, Kandapola 65 i82 ANNUAL REPORT FOR 1968 P75 — Control of Porta hypolateritia by soil treatment with chloropicrin 60 P76 — Studies on inoculum potential—Determination of the smallest effective inoculum for infection of young tea plants by P. hypolateritia 60 P77 — Fungicides for the control of Blister Blight on VP tea 62 P78 — Porosity of soil mixtures adjusted by the use of coarse sand on the growth of young VP tea plants in polythene sleeves 67 P79 — Porosity of soil mixtures adjusted by the use of compost on the growth of young VP tea plants in polythene sleeves 67 P80 — Effect of aeration on the growth of vegetatively-propa- gated nursery plants growing in polythene sleeves in clayey soil 67 P81 — Forking the soil on the growth of Clone TRI 2142 planted in heavy soil 67 P82 — Depth of root penetration on the incidence of P. theae 65 N25 — Arboricides on old tea due for uprooting, on the build up of eelworm population in replanted young tea at Great Western Estate, Talawakele 75 N26 — Arboricides on old tea due for uprooting on the build up of eelworm populations in replanted young tea at Galkandewatte Estate, Talawakele 76 N27 — Soil temperature on the build up and pathogenicity of Pratylenchus loosi in tea 76 N28 — Dose of methyl bromide required for fumigating nursery soil 77 N29 — Varietal susceptibility of potatoes to P. loosi 77 N30 — Fertilizer types and levels on pathogenicity and build up of populations of P. loosi in tea 77 N31 — The performance and tolerance of clones to the Root- Knot Nematode, Meloidogyne brevicauda at Kabara- galla Estate, Ellamulla 78 N32 — Sampling time on population levels of 3 species of parasi­ tic nematodes in tea at 7 widely-spaced locations 78 MN2 — Screening of clones for tolerance to the Burrowing Nema­ tode, Radopholus similis 00 E57 — Azinphos-methyl, fenitrothion, methyl parathion, SD 8447 (Gardona) DuPont 1179 (Lannate), GS 13005 (Supracide), DDT, aminocarb+trichlorphon and ami- nocarb for tea tortrix control 89 E58 — DDT, methyl parathion, DDT+methyl parathion, ami- nocarb, DuPont 1179 (Lannate), SD 8447 (Gardona), fenitrothion, H-14503, dioxathion, SD 9129 (Axodrin) and phosalone for tea tortrix Control 90 E59 — Heptachlor post-prune, heptachlor mid-cycle, heptachlor + Estab, heptachlor + Lovo, heptachlor-impregnated jute, endrin, endrin+Estab, endrin+Lovo, endrin im­ pregnated jute, endosulphan and dieldrin for shot-hole borer control at Ury Group, Passara 82 E60 — Heptachlor, heptachlor+Plyac, heptachlor-impregnated jute, endrin, endrin + Plyac, endrin-impregnated jute, DDT, DDT+Plyac, BHC, BHC+Lovo, fenthion, fenthion+Lovo and DuPont 1991 for Shot-hole borer control at Katabola Estate, Kotmale 82 E61 — DDT at 3 levels, DDT+Plyac, endrin at 3 levels, endrin +Plyac, heptachlor, heptachlor+Plyac and dieldrin for ' shot-hole borer control -at Katabola Estate, Kotmale 82 ANNUAL REPORT FOR 1968 183 E62 — 3 levels of Du Pont 1991, fenitrothion, fenitrothion+ Plyac, endosulphan, endosulphan + Plyac, H-14503, dioxathion, UC21149 (Temic 10G) and Du Pont 1179 (Lannate) for shot-hole borer control at Carolina Group, Watawala 82 E63 — Endrin, DDT, endrin + DDT, heptachlor, heptachlor+ Tenac, dieldrin, chlordane, perthane, methoxychlor and Resitox at two levels for shot-hole borer control at Rothschild Estate, Pussellawa 83 E64 — VCS506, Dowco 179 (Dursban), formothion, formothion, Resitox, DDT at 3 levels, endrin at 2 levels and C-10015 for shot-hole borer control at Telbedde Estate, Badulla 83 E65 — Heptachlor, endrin, endosulphan, endosulphan+Plyac, phenthoate, phenthoate + Plyac, Toxaphene, Torvidan, Toxaphene-DDT, Toxaphene + Plyac and Miltos for shot-hole borer control at Meddecombra Estate, Wata- goda 83 E66 — DDT at 3 levels, endrin at 3 levels, endrin-impregnated jute, Resitox, heptachlor, heptachlor-impregnated jute and dieldrin for shot-hole borer control at Deltotte Group, Galaha 83 E67 — Oxythioquinox at 3 levels, difocol at 3 levels, difocol+ tetradifon at 2 levels, tetradifon at 2 levels, dinobuton and Dowco 213(Plictran) for purple, scarlet and red spider mite control at Glenanore Estate, Haputale 84 E68 — Oxythioquinox at 3 levels, difocol at 3 levels, dinobuton and prothoate for purple, scarlet and red spider mite control at Welimada Group, Welimada 89 E69 — Oxythioquinox at 3 levels, difocol at 2 levels, dinobuton and Dowco 213 (plictran) for purple, scarlet and red spider mite control at Gonamotawa Estate, Haputale 89 E70 — Loss of crop caused by Tea Tortrix •' 90 E71 — Dieldrin, aldrin, heptachlor, chlordane, VC-21149 (Temik 10G), dimethoate, Dowco 179 (Dursban), phenthoate, prothoate, endrin and DDT+endrin for the control of the Low-Country Live Wood Termite at Galbode Estate, Ratnapura. 90 T33 — Paper sacks as a substitute for tea chests 104 T34 — Fermentation of teas in an atmosphere of carbon dioxide 105 T35 — Comparison of trough withering with withering on nylon tats and hessian tats during the quality season 105 T36 — Blending of clone TRI 2025 with clones possessing excel­ lent quality 106 LT9 — Drier project 108 LT10 — Instant tea project 108 LT11 — Manufacture of low-grown leaf at low temperatures 108 Extension Experiment XLA18 — 3 types of nitrogen (urea, clacium ammonium nitrate and sulphate of ammonia) and 3 levels of nitrogen on TRI 2023 at Talagaswella Estate, Talagaswela 139 i Printed by H . W. Cave & C o . , Ltd., Gaffoor Building, Main Street, C o l o m b o 1 for the Tea Research Institute of Ceylon, St C o o m b s , Talawakele.