T H E TEA RESEARCH INSTITUTE OF CEYLON Report for the Ye*ir 1969 Part II Edited by L. H. FERNANDO, BSc PhD (Lond) and \ . N. SHANMUGANATHAN, BSc (Gey), PhD (Lond) V Published by THE TEA RESEARCH INSTITUTE OF CEYLON ST COOMBS, TALAWAKELE, CEYLON 1971 C 0 N T E N T S PAGE The Board of the Tea Research Institute of Ceylon 5 The Staff of the Tea Research Institute of Ceylon 7 Report of the Director 11 Report of the Agricultural Chemistry Division 2 0 Report of the Agronomy Division 42 Report of the Plant Physiology Division 6 0 Report of the Plant Pathology Division 79 Report of the Nematology Division 97 - Report of the Entomology Division . . 108 Report of the Biochemistry Division 124 Report of the Technology Division . . 13) Report of the Statistics Division 144 Report on the Low-Country Station and the Kottawa Substation 145 Report on the Mid-Country Station . . 168 Report on the Uva Station .. .. . . . . 176 Report on St Coombs 181 Report on St Joachim . . 189 Meteorological Observations The Tea Research Institute Laboratory, Talawakele .. . . 196 The Low-Country Station, Ratnapura . . 197 The Mid-Country Station, Kandy 198 The Uva Station (Gonakelle), Debedde .. 199 Index to field experiments, trials & factory experiments . . 200 The Tea Research Institute of Ceylon Hie Board as at 31st December 1969 Chairman : Mr. S. Pathmanathan 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 The Chairman, Agency Section, Planters' Association of Ceylon : Mr S. K. D. Jayamanne The Chairman, Low-Country Products Association of Ceylon : Mr G. Hettiarachchi The Tea Controller : Mr C. P. Chanmugam The Director, Tea Research 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. Pedes Mr M. B. Horsfall Appointed by the Low-Country Products Association of Ceylon : Mr S. Pathmanathan Mr J. L. D. Peiris Mr L. C. de Mel Appointed by the Honourable the Minister of Agriculture to represent the smallholders : Mr D. E. Hettiarachchi, JP, UM 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 W. D. A. E. S. Wanigesekera 5 TEA RESEARCH INSTITUTE Of CEYLON |THE STAFF (On 31st Deoember 1969) DIRECTORATE Director ; . . . . Deputy Director (Administration) L. H. Fernando, BSc, PhD (Lond) W. D. A. E. S. Wanigesekera, BA (Cey) Agricultural Chemistry Agricultural Chemist Research Assistant . . Technical Assistants RESEARCH DIVISIONS V. P. Bhavanandan, BSc (Cey), PhD (Edin), ARIC *S. Sivasubramaniam, BSc (Cey), DIC, ARIC V. Fernando T. C. Z. Jayman T. Kularatna, BSc (Cey) S. Sunderalingam, BSc (Poona) A. B. D. Wickremaratne, BSc (Vidyodaya, Cey) Agronomy Research Officer Research Assistant . Technical Assistants Biochemistry Biochemist Research Officers . Technical Assistants Entomology Entomologist Technical Assistants Hematology Nematologist Technical Assistants W. M. W. B. Manipura, BSc (Cey), PhD (Cantab) *S. Sandanam, BSc (Cey) S. G. Jayasuriya C. C. Rajasingham A. Somaratne, BSc < 0. 05) = 0.026 (P < 0. 01) = 0.035 (P < 0.001) = 0.046 b) Highly significant increases in the available phosphorus in the soil, as determined by Olsen's method, were noticed with increasing levels of phosphate applied to the soil. Levels of P 2 0 5 (lb/acre/year) 0(P0) 30(P1) 60(P2) Available P (ppm) by Olsen's method 0.97 6.51 29.62 LSD (P < 0 . 05) = 7.33 (P < 0. 01) = 9.84 (P < 0.001) = 12.89 The levels of nitrogen and potash applied had no influence on the phosphorus content of the soil. c) The available phosphorus in the soil, as determined by each of the three methods, was in all cases highly correlated to the phos­ phorus in the leaf. Of the three methods used for soil phosphorus determination, Olsen's bicarbonate method gave the best correla­ tion. d) The yield obtained over a two-year period was not correlated either to the leaf phosphorus content or to the available phosphorus in the soil as determined by any of the three methods. An interesting observation in these studies is that even though the available phosphorus in the soil between treatments PI and P2 increased from 6.51 to 29.62 ppm, there was no corresponding increase in yield. (Refer Experi­ ment Al for yield response). It is thus obvious that there is a large accumula­ tion of phosphorus in the soil due to continuous manuring with phosphate fertilizers. The plant is able to use this excess only to a limited extent, as seen in the increase of leaf P from 0.169 to 0.196 between PI and P2. This increase in leaf P is not reflected in an yield increase suggesting that there is a luxury consumption of P by the tea plant. T. C. Z. Jayman and D. P. Wickremaratne 22 ANNUAL REPORT FOR 1969 Analysis of leaves from clonal testing experiments for certain nutrients To formulate a foliar diagnostic technique for giving advice on fertilizers it is essential to investigate and wherever possible standardize the large number of factors which influence the nutrient content of leaves. Hasselo (1965) studied the variation of certain nutrients in the leaves of clonal tea (TRI 2024) grown in two districts (Oimbula and Ratnapura) and also the variation of the nutrient content with the age of the leaf. Experiments have been initiated to study the influence of some of the factors on the nutrient content of tea leaves. Clonal tea is best suited for this purpose because of the uniformity of bushes which is lacking in seedling tea. Analysis is being carried out monthly for nitrogen, phosphorus, potassium, calcium and magnesium on leaves from six clones (TRI 2023, TRI 2024, TRI 777, DT 1, DG 39, and CY 9) grown under shade and no shade in Experiment VP1 at St Coombs. The results should give us some information on clonal and sea­ sonal (climatic) variations, influence of fertilizer application and of shade. Analyses are also in progress for the same nutrients of leaf samples collected from the same clones in Experiment LVP1 (Kottawa Sub-station) and MVP1 (Hantane Sub-station). These results would give some idea of the variation due to locations. T. C. Z. Jayman Fractionation of the phosphorus components in tea soils Soils from two tea fields and one jungle area in St Coombs were used for this study. The procedure of Chang and Jackson (1957) was used for the phosphorus fractionation. The results are given in Table 1. TABLE 1 — Inorganic and total phosphorus in tea soils SoU PH Total Fe A l - P Fe-P Ca-P Total P (%> (ppm) (ppm) (ppm) (ppm) Field No. 9 4.40 5.48 10.0 39.0 81.0 600 Field No. 3 4.50 6.84 60.0 46.0 49.0 480 Jungle 4.90 5.32 3.0 32.0 18.0 260 It is seen that the total phosphorus in unfertilized jungle soils is about 50% of that of tea soils. Of the three inorganic phosphates, iron phosphate is predominant in jungle soil. It is generally considered that iron and alumi­ nium phosphates are forms available to the plant. High calcium phosphates in the tea soils examined are probably due to accumulation of phosphate ferti­ lizers. T. C. Z. Jayman Placement experiments with labelled phosphorus Phosphate labelled with radioactive phosphorus (P82) was applied round tea plants of clone TRI 2024 at a distance of 9 inches. Three methods of placement were employed, namely surface application, placement at a depth of 4 in. and 8 in. The treatments were replicated thrice and each plant received 0.35 millicuries of P 3 2. Flush and mature leaf samples were collected at various intervals and activity counted after drying and grinding to a powder. Even after five weeks the activities detected in the samples from the treated plants were not significantly different from that in the control plants. It thus appears that none of the treated plants have taken up the phosphate applied. Weeds collected close to the surface-treated tea plants were found to have high activity. These studies are continuing. V. Fernando ANNUAL REPORT FOR 1969 23 Silicon in tea plants The very poor yield response of tea to phosphatic fertilizers in field experi­ ments and the successful growth of tea in phosphorus deficient medium in sand culture experiments (Pethiyagoda 1970) are rather unusual. It has been suggested that certain plants are able to substitute at least part of their phos­ phate requirement with silicate. To find out whether such a situation occurs with tea, leaf samples from Experiment Al were analysed for silicon. As an initial step, composite samples of mature leaves from the plots receiving the three different levels of phosphate (0, 30 and 60 lb P 2 0 6 per acre per year) were analysed for silicon by the molybdosilicic method (Jackson 1938). The results were as follows : P 2O s (Ib/acre/year) 0 30 60 Silicon (ppm) 830 750 950 From this preliminary investigation there appears to be no relationship between silicon in the leaf and phosphate applied to the soil. T. C. Z. Jayman Ammonium nitrogen vs nitrate nitrogen for tea in sand culture The details together with the preliminary results obtained from this ex­ periment were given in last year's report. The summary of the results are given in Tables 2 and 3. TABLE 2 — Growth and nitrogen absorption by young tea plants grown in ammonium and nitrate medium Medium Fresh weight Fresh weight Total N in the Total N '5 in the of plant (g) of roots (g) plant (mg) plant (mg) Ammonium—N 19.3 7 .2 111.9 11.9 Nitrate—N 18.9 6.2 58.7 6.7 TABLE 3 — N1* nitrogen (mg) and N16/Nu ratio in the nitrogen fractions of the tea plants grown in ammonium and nitrate medium Medium Ammonium—N Nitrate—N 0.11 0.04 0.144 0.129 0.42 0 . U 0.155 0.186 0.78 0.37 0.149 0.224 0.89 0.90 0.084 0.092 2.62 0.30 0.113 0.169 Ammonium Amide Nitrate Caffeine Amino Acid N'5 N'J/N '4 N«s N'VN'« N'5 N'5/N'* N'5 N'5/N«* N '5 N'5/N'4 Protein N'5 N , J /N ' 4 7.08 0.089 5.01 0 . U 2 TABLE 4 — Elemental analysis of leaf, stem and root of plants grown in ammonium and nitrate medium % N % P % K % Ca % Mg Mn (ppm) Al (ppm) Medium Leaf Stem Root Leaf Stem Root Leaf Stem Root Leaf Stem Root Leaf Stem Root Leaf Stem Root Leaf Stem Root Ammonium 3.77 1.47 2.31 0.43 0.26 0.34 1.95 0.73 1.75 0.28 0.11 0.10 0.21 0.01 0.06 350 86 111 460 540 690 Nitrate 2.79 1.20 1.68 0.42 0.53 0.46 2.35 2.75 2.05 1.38 0.50 0.50 0.26 0.31 0.23 288 111 68 410 230 410 ANNUAL REPORT FOR 1969 All figures in both tables are the averages of two determinations, except the amino acid figure of the ammonium plant. From these results, it appears that under the conditions of the experiment there was no obvious difference in the growth of the plants, as assessed by the total plant and root weights. How­ ever, the total nitrogen assimilated by the ammonium plant was about twice that assimilated by the nitrate plant. This is indicated by the total nitrogen as well as the labelled nitrogen (N1 5) found in the two plants. The N 1 5 in the nitrogen fractions are higher in the ammonium plant, the only exception to this is the N 1 5 in caffeine which is equal in both plants. That even the nitrate fraction is higher in the ammonium plant is rather surprising. There appears to be a much larger accumulation of amino acids in the plant grown on ammo­ nium nitrogen. Once taken up the assimilation of both forms of nitrogen appears to be equally efficient as shown by the almost uniform incorporation of the labelled nitrogen into all fractions (see N 1 4 : N 1 5 ratios in Table 3). The leaves, stems and roots from the plants grown in the two media were analysed for seven elements. The results are given in Table 4; the figures are averages of two values. The percentages of nitrogen in all components of the ammonium plant are higher than those of the corresponding components in the nitrate plant. Potassium, calcium and magnesium are consistently higher in the components of the nitrate plant. This effect is most probably due to the depressing effect of the ammonium cation on the uptake of the potassium, calcium and magnesium cations. The uptake of the anion nitrate leads to absorption of more of the cations. There is no special trend with respect to phosphorus, manganese and aluminium, except that the phosphorus in the stem of the nitrate plant is twice as much of the ammonium plant. T. Kularatna Nitrate reductase This enzyme activity is important if any plant is to metabolize nitrate nitrogen. All earlier attempts to detect this enzyme activity in the tea plant have been unsuccessful (Sanderson and Roberts 1969). Different procedures and techniques were initally tested using tomato and citrus leaves both of which are known to contain this enzyme activity. The method of Bar-Akiva and Sternbaum (1965) where leaf discs instead of ground homogenates are used was found to be the best of the ones tested. All our attempts, so far, to detect the above activity in tea leaves of diffe­ rent age and tea shoots have failed. Addition of polyclar, a polyphenol absorbant (Sanderson and Perera 1966), to the incubation mixture did not alter the results. A significant drop in nitrate reductase activity of tomato leaves occurred on addition of tea leaf discs into the incubation mixture. It is thus possible that a component, other than polyphenol, in the tea leaf might be inhibiting this enzyme activity. Experiments with tea roots gave a positive test for the nitrate reductase activity, when polyclar was added to the incubation mixture containing frag­ ments of tender tea roots. T. Kularatna High pH and growth of tea The pot experiments initiated to study the above relationship had to be abandoned due to the failure of a large number of plants to establish. The disturbing effect of the thorough washing of the roots which was carried out when the young plants were transferred from the polythene bags to the pots may be responsible for the failure. ANNUAL REPORT FOR 1969 However, this subject was investigated in a field experiment at Brookside Group, Halgranoya (See Experiment A28). T. Kularatna Flonride in tea Warren & co-workers (1968) in England investigated the availability of flouride in tea and coffee in order to assess the role of tea drinking in arresting dental caries. They examined two samples of Ceylon tea, one from a Nuwara Eliya estate and other from an Uva estate, and found that the flouride con­ tents were 154 and 111 ppm of dry tea respectively. They also found that 32.9 % and 68.3 % respectively of the flouride in the above teas were chemically available, ie these percentages of the total flouride were extracted into the tea liquor. Further, it is reported that only 2 4 % and 1 7 % respectively of the total flouride were ionizable after addition of milk, as detected in the dia- lysate. Work on the above lines was undertaken in order to study the variation of the flouride content of tea from different districts in Ceylon. Initially different grades of made tea samples from four estates were analysed for total flouride. These were some of the samples received by us for analytical work for the Bureau of Ceylon Standards. The results are given in Table 5. TABLE 5 — Total flouride {ppm) of some Ceylon teas Estate District Grade of tea BOP OP BOPF Dust BM Average Court Lodge Nuwara Eliya 144 155 175 212 — 172 Dyraba Badulla 179 177 158 — — ' 171 Galaha Kandy 169 187 153 167 169 Storefield Pussellawa 155 146 136 146 The figures in the Table are averages of three determinations carried out on samples received in three consecutive months. Flouride estimations of the liquor of the above teas showed much larger percentages of total flouride than those reported by Warren et al. This in­ vestigation is being continued. T. Kularatna Flonride, aluminium interactions Mature leaf samples collected from the plants of a sand culture experi­ ment were analysed for aluminium, flouride, sodium and potassium. Details of the sand culture experiment Which was carried out to determine the uptake of flouride as well as the interactions between aluminium and flouride, can be found in the report of the Plant Physiology Division. The analytical results are summarized in Tables 6 and 7. ANNUAL REPORT FOR 196$ 27 TABLE 6 — Influence of flouride applied on the flouride, aluminium, potassium and sodium content of tea leaves Flouride applied (ppm) Flouride (ppm) Aluminium (ppm) Potassium (%) Sodium (%) 0 20 285 2.05 0.205 1 214 224 1.99 0.211 2 364 185 2.12 0.206 4 662 166 2.09 0.216 LSD (P < 0.05) (P < 0.01) 96 138 51 74 NS NS Increasing amounts of flouride and decreasing amounts of aluminium are taken.up with increasing levels of flouride applied. Uptake of potassium and sodium are not influenced by the different levels of flouride applications, in spite of the flouride being applied as sodium flouride. TABLE 7 — Influence of application of aluminium on the flouride, aluminium potassium and sodium content of tea leaf Aluminium applied (ppm) Flouride (ppm) Aluminium. (ppm) Potassium (%) Sodium (%) 0 312 162 2.00 0.195 1 310 198 2.09 0.219 2 278 .222 2.07 0.205 4 360 277 2.08 0.219 LSD {P < 0.05) (P < 0.01) NS 51 74 NS NS The level of aluminium applied has an effect only on the amount of alu­ minium taken up; it has no influence on the uptake of flouride, potassium or sodium. T. Kularatna Influence of mulching on soil pH, carbon and nitrogen Soils for this study were obtained from Experiment PH5 investigating the influence of mulching and NPK levels on yield (see report of the Plant Physiology Division). The five treatments are mulching with leaves of tea, Grevillea robusta, Dadap or Mana and unmulched control. The levels of nitrogen are 45, 135 and 225 lb per acre per year given in the form of T 700 mixture. Mulch in the form of green leaf is applied monthly to provide 6.2 tons fresh matter per acre per annum. Fertilizer is applied at four-month intervals. The treatments were started in 1965. Soil samples from the different mulch treatments all receiving the middle level of nitrogen, ie 135 lb per acre per annum, were used for the pH determinations. The results are given in Table 8. TABLE; 9 — Urease activity of soils from the TRI Stations Location Depth (inches) 0—6 6—12 12—18 18—24 St Coombs Range Mean 21.8—57.5 39.6 20.2—28.5 23.7 12.6—20.4 14.8 11.9—16.7 13.9 St Joachim Range Mean 24.3—103.2 49.7 21.2—30.6 25.4 14.0—26.4 18.2 12.8—19.3 14.9 Hantane Range Mean 42.7—73.9 60.4 29.5—52.4 40.3 22.9—32.8 26.8 14.5—22.8 19.5 Passara Range Mean 30.3—98.4 57.8 26.6—72.6 42.1 22.4—40.6 31.5 21.0—40.6 30.9 ANNUAL REPORT FOR 1969 29 TABLE 8 — Effect of three years mulching at 6.2 tons fresh matter per acre per annum on soil pH Mulching pH of soil at various depths (in.) treatments 0-2 2-4 . 4 - 6 6-12 12-18 Tea 4.19 4.05 4.18 4.24 4.21 Grevillea 4.24 4.15 4.21 4.18 4.26 Dadap 4.01 4.06 4.19 4.23 4.31 Mana 4.21 4.09 4.08 4.15 4.21 Control 4.00 3.95 4.06 4.19 4.28 LSD (P < 0.05) 0.18 (P < 0.01) 0.26 There is no significant difference in soil pH at any depth between the Dadap treatment and the untreated control. Mulching with tea, Grevillea or Mana leaves increased soil pH in the 0-2 in. depth significantly. Mulching with Grevillea leaves is the only treatment which significantly increased soil pH in the 2-4 in. depth. At depths below four inches, none of the treatments had any influence on soil pH. The organic carbon and nitrogen contents of the above soil samples were also determined. Changes in soil organic carbon and nitrogen due to mulching in the 0-2 and 2-4 in. depths are shown below. Mulching treatments Organic 0-2 in. Carbon (%) 2-4 in. 0-2 in. Nitrogen (%) 2-4 in. Tea 8.20 4.32 0.59 0.41 Grevillea 7.80 4.56 0.45 0.33 Dadap 5.92 6.14 0.32 0.34 Mana 8.59 4.89 0.49 0.32 Control 6.62 4.56 0.49 0.26 Mulching with tea, Grevillea or Mana leaves increased the organic carbon of the soil in the 0-2 inch depth, but not in the 2-4 inch depth. Mulching with dadap leaves has not changed the organic carbon in the top layer of the soil but surprisingly increased the carbon in the 2-4 inch depth. Mulching with tea leaves is the only treatment where the nitrogen content of the soil in the top layer (0-2 inch) increased. In the lower depth (2-4 inch), all treatments increased the soil nitrogen content. T. Kutaratna Urease activity in soils from different districts i Urease activity determination was carried out on soils from the TRI stations. The range of the urease numbers and the mean values for the different soils are tabulated (Table 9). ' Comparing the means it appears that the Hantane and Passara soils have a higher urease activity than those of St Joachim and St Coombs soils. Variation in urease activity is greatest in St Joachim soils and least in St Coombs. It was evident that in future studies, the time (season) of sampling, the mois­ ture content of the soil at the time of sampling, and the effect of storage on the urease activity of the soil would have to be taken into account. V. Fernando 30 ANNUAL REPORT FOR 1969 Urease activity and depth of soil Preliminary studies show that even the 0-1 inch layer of the soil has considerable urease enzymic activity. Further, the variation in the urease activity of the soils in the top three inches (0-1, 1-2 and 2-3) was minimal compared with the variations in the lower layers of the soil (0-6, 6-12, 12-18 and 18-24 inches). (Refer to last year's report). V. Fernando Urease activity, types of nitrogen treatment and time of sampling Soil samples from Experiment A4 were analysed for urease activity at weekly intervals for a period of four months. Eight samples were collected during the wet period, August-October, and eight during February-March, which was a comparatively dry period. The differences in the urease numbers between the types of nitrogen treatments were found to be highly significant as shown below. Treatment Urea Calcium Sulphate ammonium of ammonia nitrate Urease Number 38.1 29.6 23.4 LSD (P < 0.05) 5.4 This confirms our earlier observation that continuous urea fertilization increases the urease activity in the soil. There is no significant difference in the urease activity between times of sampling. V. Fernando Urease determination under field conditions The urease activity of a soil is normally determined in the laboratory under standardised conditions of pH and temperature. The pH is maintained by addition of a buffered solution of citrate, resulting in a soil suspension which would be expected to be more favourable for enzymic reactions. However, when urea is applied in the field the conditions are not the same as above. The pH of the soil is variable and the soil does not have the same buffering capacity as a buffered solution. Further, even though the soil water would dissolve the urea and bring it into contact with the soil, the degree of urea soil urease contact would not be the same as in a soil suspension. Thus in order to compare the conversion of urea to ammonium under field conditions with that obtained by the laboratory procedure, the following experiment was carried out. In one set, lOg portions of the soil were mixed with 20 ml citrate buffer of pH 6.7 and lg urea in flasks. In the second set, lOg portions of soil at field moisture level were mixed with lgurea and sealed in polythene bags. Both sets were incubated at 37°C. Duplicates were removed from both sells after 1 and 3 days and analysed for ammonium nitrogen. The results are given in Table 10. ANNUAL REPORT FOR 1969 31 TABLE 10 — Transformation of urea into ammonium by soil urease under different incubation condi­ tions Mg ammonium—N formed per Treatment lOOgsoilin 1 day 3 days Soil + urea in citrate buffer (20 ml) 99.8 465.5 Soil + urea, no buffer 110.7 362.0 It appears that the conversion of urea to ammonium under field conditions is comparable to that determined by the laboratory procedure if the time of incubation was one day. But if the incubation is continued for three days, the conversion of urea to ammonium under the field conditions slows down probably due to insufficient mixing of the substrate and the enzyme. V. Fernando Transformation and movement of urea in soil under field conditions In this experiment the conversion of urea into ammonium and nitrate and the movement of the three forms of nitrogen in the soil were investigated. Urea was broadcast at the rate of 100 lb N per acre on two experimental plots and two other plots in the same area were treated as controls. Since it was our intention, to conduct this experiment under rainy conditions, on dry days the plots were watered to simulate a rainfall of 0.1 inch. Soil samples from all the plots were analysed for pH, urea-N, ammonium-N and nitrate-N, It was found that for the duration of the experiment (nine days) there were no significant differences in the nitrate-N between the treated and control plots. It was found that the conversion of urea to ammonium had started within •24 hr of application and at 120 hr only a very small amount of urea was un­ converted. After 72 hr only about 10% of the nitrogen was in the form of urea in the first two inches of the soil. In this experiment it was noticed that the pH of the first four inches of the soilwas on an average about 0.5 units higher in the treated plots. This increase of pH during incubation of soil with urea, which was also noticed in laboratory experiments was found to be a temporary effect. V. Fernando Volatilization losses from urea applied to the soil The studies reported in 1968 were further extended. (1) Volatilization losses from urea applied either alone or in mixtures with saphosphosphate and muriate of potash were as follows :— Nitrogen lost as ammonia (%) Treatment 1st Experiment 2nd Experiment Urea 26.3 13.2 Urea + saphosphosphate 26,0 13.3 Urea + saphosphosphate + muriate of potash 23.3 14.8 Figures quoted are averages of duplicate determinations. Urea was applied at the rate of 100 lb N/per acre, saphosphosphate at the rate of 30 lb P 2 O S per acre, and muriate of potash at the rate of 60 lb KJJO per acre. 32 ANNUAL REPORT FOR 1969 bation (days) PH Urea—N (mg) Urea—N hydrolysed (mg) N H 4 - N recovered (mg) Nitrogen lost* (mg) N H 4 - N lostt (mg) 0 5.05 2250 — — — — 3 9.60 2070 180 174 6.0 3.0 7 9.60 2000 250 220 30.0 26.3 12 9.60 1890 360 247 113.0 75.7 * By difference t By bell jar experiment It appears that nitrogen lesses as determined by the above method are somewhat more than those obtained under the bell jar. V. Fernando Urea foliar absorption Some preliminary studies were carried out in the laboratory using freshly cut tea shoots standing in water. Urea solution was applied to the leaves using cotton wool. Before analysis the leaves were cleaned with alcohol to remove unabsorbed urea. The information obtained is given below. Mixing either saphosphosphate or saphosphosphateond muriate of potash with urea does not seem to have any significant influence on the loss of nitrogen as ammonia from urea. (2) Loss of nitrogen as ammonia was less when urea was applied to the soil under a good cover of tea as compared to an exposed area. Average values of two separate experiments are given below. Nitrogen (%) lost as ammonia Exposed soil 17.4 Soil with a good cover of tea 11.8 (3) In preliminary experiments it was found that nitrogen losses from urea were greater when urea was mixed with dolomite prior to appli­ cation to the soil. These studies are continuing. V. Fernando Losses of nitrogen from urea applied to the soil as determined by a modified technique In the experiments reported previously, nitrogen losses from urea were measured by absorbing the ammonia released in acid-soaked filter paper under bell jars. This method obviously imposes a restriction because under a bell jar conditions are different to those on exposed soils. An alternative method was therefore tried out to check the reliability of the bell jar technique. In this procedure, 5g urea was spread on 50g soil at field moisture capacity, and incubated at 30°C. Samples of soils were analysed at various intervals for urea-N, ammo- nium-N and pH. The results are given in Table 11. TABLE 11 — Volatilization losses of nitrogen from urea applied to soil as measured by two different methods ANNUAL REPORT FOR 1969 33 1 — Between three to four times more urea was absorbed by the lower surface of the leaf as compared to the upper surface (Table 12). TABLE 12 — Absorption of urea by tea leaves Surface to which Concentration of urea Mg urea absorbed per urea applied solution (%) lOOg fresh leaf Upper 1 1.6 Lower 1 4 .2 Upper 2 5.7 Lower 2 27.5 2 — Increasing the concentration of urea solution applied increased the amount absorbed. 3 — Absorption of urea increases with time as shown below. Time from application (hr) 1 2 4 Mg urea absorbed by lOOg fresh leaf 14.7 20.5 26.3 Studies on the absorption and metabolism of the different forms of nitrogen by the tea plant An investigation was undertaken to study the absorption, translocation and metabolism of the three forms of nitrogen, namely ammonium, nitrate and urea. Three-year-old plants of clone TRI 2142 grown in large cement pots were used for this investigation. The plants were divided into three groups of six each; five plants in each group were treated with nitrogen, while the sixth was maintained as control. Sulphate of ammonia, calcium nitrate and urea were applied to the three groups respectively, to supply 41g of nitrogen per plant. After application of nitrogen the soil in the pots were covered with polythene sheets to prevent leaching by rain. All pots were uniformly watered whenever necessary. One plant from each set was pruned 24 hr after nitrogen application and xylem sap collected by the method of Selvendran (1969). This was repeated 48, 72, 96 and 120 hr after nitrogen application, using one plant per treatment on each occasion. The collected exudates were kept frozen until ready for analysis. The exudates were analysed for total nitrogen, ammonium, nitrate, urea, amino acids and certain other ions (potassium, calcium, phosphate, sulphate, etc). The full results are not yet available, but the following observations have been made. (1) In the plants supplied with sulphate of ammonia, large amounts of nitrogen as amino acids and ammonium were present in the xylem sap. The total nitrogen and amino acid nitrogen in the sap increased with time from application of fertilizer, but the concentration of ammonium decreased after reaching a peak. The main amino acid transported to the leaves was glutamine. Smaller amounts of thea- nine and asparagine were detected three days after application of fertilizer (see also Report of the Biochemistry Division). Consi­ derable amounts of sulphur as sulphate, were also present. (2) In the plants fertilized with calcium nitrate, the amounts of nitrogen in the sap were very little compared with those in the sap o f the plants treated with sulphate o f ammonia. Further, nitrate was the only detectable form of nitrogen in the sap. As would be expected, large amounts of calcium were also present in the sap. 34 ANNUAL REPORT FOR 1969 (3) In the sap of the plants treated with urea, large amounts of nitrogen as amino acids, ammonium and urea were present. Again the major amino acid was glutamine. Levels of sulphate of ammonia and soluble nitrogen in tea leaves V. Fernando Leaf samples collected from Experiment A8, where effect of three levels each of N, P and K on clonal tea (TRI 2024) are being tested, were used in this study. The nitrogen levels tested are 100, 200 and 300 lb N per acre per year and the form of nitrogen is sulphate of ammonia. In addition to the main treatments, there is one plot in each block receiving no fertilizer. The mature leaves were dried, ground and extracted with boiling water. Aliquots of the extract were analysed for total soluble nitrogen and for total amino acids. Preliminary results indicate that the differences in the total soluble nitrogen in the leaf from the different the nitrogen treatments are very much greater than that of total nitrogen content (Table 13). TABLE 13 Total and soluble nitrogen content of mature tea leaves from Experiment A8 — St Coombs Treatment 0 b N/acre/annum) 0 100 200 300 Total N ( % ) 2.61 3.21 3.57 4.00 Increase in total N over control (%) 23 37 53 Total soluble N ( % ) 0.707 1.097 1.322 1.523 Increase in total soluble N over control (%) 55 87 115 Cation exchange capacity (CEC) of roots of VP tea V. Fernando As reported last year under the heading 'Yield potential of VP tea' it was intended to investigate whether the CEC of roots of tea was correlated to the yield. Ten plants each of eight clones with known yield potentials were select­ ed for this study. The plants selected were approximately seven months old and of uniform growth. The roots of the plants were separated into fine and medium roots by visual estimation, dried and weighed. The cation exchange capacity of the ground (to pass No. 20 sieve) fine roots was deter­ mined by the method of Crooke (1964). The results are given in Table 14, together with the yield given by these clones over a three-year period. TABLE 14 — Cation exchange capacity and yield of clonal tea Clone Yield of made tea Ob/acre/annum) CEC of fine root (me/lOOg) Total CEC of fine roots (me) TRI 2025 2881 21.11 1.44 TRI 2023 2821 18.89 1.25 KEN 16/3 2448 21.60 1.10 TRI 2151 2418 21.20 0.87 NL 3/1 1747 21.14 0.82 TRI 777 1714 20.19 0.59 EN 31 1227 20.88 0.73 4 1198 2^.58 1.33 ANNUAL REPORT FOR 1969 35 The variations in the cation exchange capacity per lOOg root appear to be random and unrelated to the yield. But there seems to be some correlation between the yield and the total cation exchange capacity of the roots. The main reason for this could be the correlation which is reported to exist between the mean root weight and yield (Kulasegaram 1968). It is intended to repeat the cation exchange capacity determinations on roots with sufficient replicates in order to test for correlation statistically. D. P. Wickremaratne Bromine in methyl bromide fumigated soil and its absorption by the tea plant Soils consisting of a composite of ten soil cores (depth 0-6 in.) were taken from a plot (200 sq. ft) before and after fumigation with methyl bromide (1 lb/100 sq. ft). Samples (lOOOg) of the above soils were extracted with water (3 1), filtered, concentrated, passed through a column of Polyclar AT to remove polyphenols and made up to 10 ml. Aliquots of this were analysed for total halides by silver nitrate titrations using dichromate indicator. Sepa­ rate aliquots were freed of cations by passage, through columns of Amberlite CG-45 resin and then fractionated on a column of anion exchange resin Dowex 1 x 8 in the nitrate form. The chloride and bromide in the fractions from the anion exchange columns were also estimated as described above. The results are given in Table 15. TABLE 15 — Water extractable chloride and bromide of soil before and after fumigation with methyl bromide Before fumigation After fumigation Chloride Bromide (ppm) (ppm) 13.9 6.2 14.1 12.3 The difference in the chloride content of the two soils is within experi­ mental error, but there is an almost 100% increase in the soluble bromide in fumigated soil. This increase corresponds to a retention of about 7% of the bromine in the methyl bromide as water soluble bromide in one foot of soil. Chloride and bromide determinations were also carried out on leaf samples collected from one-year-old tea plants grown on fumigated plots and on ad­ jacent unfumigated plots. The differences in the chloride and bromide con­ tent of the leaves from the two sets of plants are negligible as shown below. Chloride Bromide (ppm) (ppm) Unfumigated soil 511 322 Fumigated soil 501 318 R. R. Selvendran and V. R. N. Mtinasinghe Field Experiments and Trials Al — NPK at No. 3 field, St Coombs — (1931) Yield responses for the third year of the 12th cycle are given in Table 16. The results are similar to those obtained during the 2nd year of this cycle. 36 ANNUAL REPORT FOR i960 TABLE 16 — Yield response for the third year of the \2th cycle Treatment Yield (lb/acre/annum) (lb/acre/annum) N 120 1398 180 1532 240 1676 pso5 0 1369 30 1661 60 1576 K a O 0 883 75 1875 150 1848 LSD (P < 0 . 05) 146 (P < 0 . 01) 197 (P < 0.001) 261 A significant yield response was obtained up to the highest level of nitrogen tested. A highly significant response was obtained to 30 lb P 2 0 5 but there was a slight depression at the higher level of 60 lb P 2O s. The response to 75 lb KaO was highly significant, but there was no further increase in response to an additional 75 lb K 2 0. D. P. Wickramaratne A4 — Type of nitrogen at No. 9 Field — (1961) The results of the 2nd year of the present cycle are shown in Table 17. TABLE 17 — Yield trends in relation to type of nitrogen during the second year of the third cycle Yield Treatment Yield Treatment (lb/acre/annum) (lb/acre/annum) (lb/acre/annum) Sulphate of ammonia 2190 150 N 1962 Urea 2004 300 N 2121 Calcium ammonium nitrate 1932 LSD (P < 0.05) 193 LSD (P < 0.05) 158 The difference in yield between the two levels of nitrogen is significant (P < 0.05). As for the types of nitrogen, the yield difference between sul­ phate of ammonia and calcium ammonium nitrate is also significant (P < 0.05). The yield difference between sulphate of ammonia and urea just fails to reach significance. This is the first time in the eight years since this experiment was started significant yield differences have shown up between the types of nitrogen. Manufacturing tests on flush from this experiment were carried out by the Technologist and the results are reported in the Report of his Division. S. Sunderalingam A5 — Frequency of application and forking of nitrogen (urea) at No. 3 Field — (1963) ANNUAL REPORT FOR 1969 37 During the second year of this new cycle in which urea was substituted for sulphate of ammonia no yield difference was observed between the fre­ quency treatments (2, 3 and 4 applications per year). The difference in yield between the two levels of urea, viz 120 and 240 lb N per acre per annum, was significant at the 5% level of probability. In the third year, beginning in October 1969, a new treatment, namely methods of application, was introduced on split plots to investigate the effect of forking on urea applications. Urea is forked in on one half and broadcast on the other half of each plot at every application. Saphosphosphate and muriate of potash are broadcast uniformly to the whole plot in four applica­ tions per year. S. Sunderalingam A7 — Distribution and forking of nitrogen (urea) at No. 13 Field — (1963) The results of this experiment for one year from the time of introduction of the new factor (forking) in December 1968 were statistically analysed. There was no significant difference in yield between the two methods of distri­ bution of urea (alternate and double row applications) or between broadcasting and forking in of urea. However, a very highly significant yield difference was evident between the two levels of urea tested, namely 75 and 225 lb N per acre per annum. N(75) 1982 N(225) 2463 S. Sunderalingam A14 — Three levels of nitrogen (urea), 3 levels of potassium, 3 frequencies of application and 3 methods of application of urea on VP tea at Tangakelle Group, Lindula — (1967) The treatments are as follows :— 3 levels of urea (100,200, 300 lb N per acre per annum) 3 levels of potash (50, 100,150 lb KzO per acre per annum) 3 frequencies of application of urea and potash (3, 4 and 5 applica­ tions per year), and 3 methods of applications of urea (broadcasting, spraying on soil and soil injection). The treatments were started in May and the results will be analysed at the completion of one year. S. Sunderalingam & D. P. Wickremaratne A17 — Three levels of urea and 3 methods of application on VP tea at Nos. 8 and 16 Fields — (1968) In this experiments the treatments are :- 3 levels of urea (120, 240 and 360 lb N per acre per year) 3 methods of application (broadcasting and soil injection in 3, 6 and 9 applications per year, and foliar spraying in 8, 16 and 24 applica­ tions per year). The treatments were started in September. S. SiindcraliBgaa 38 ANNUAL REPORT FOR 1969 1969 Field Experiments A27 — Sulphate of ammonia, urea and calcium nitrate and other soil treatments on two clones at No. 9 Field—4x3x2 with 2 replicates — (1969) The three types of nitrogen, all at the same level, and no nitrogen are being tested on young plants of clones TC 9 and TRI2027. The other soil treatments studied in this experiment are no fumigation, fumigation with methyl bromide (1 lb/100 sq. ft) and treatment with "AM" (an inhibitor of nitrification). The tea in this experiment was planted out in November. It was reported earlier (Tolhurst 1967) that highly significant responses to the growth of young tea plants was obtained by methyl bromide fumigation of the soil. It has also been reported that the ammonium content of methyl bromide fumigated soil remains high for a long period compared with un- fumigated soil (Shanmuganathan & Fernando 1967). This is probably due to suppression of nitrification as a result of destruction of nitrifying organisms of the soil by methyl bromide. If this is correct, then treatment of the soil in and around the planting holes with "AM"> which is an inhibitor of nitrifying bacteria, should have a similar or at least comparable effect on the growth of young tea plants. The changes in the ammonium and nitrate nitrogen of the soil (0-6 inch depth) after the different soil treatments were followed for a period of 48 days. The results are given in Table 18. TABLE 18 — Changes in ammonium and nitrate nitrogen due to different soil treatments Ammonium—N(ppm) Nitrate—N(ppm) Soil treatment 12 24 48 12 24 48 (days) None 18.0 15.6 15.7 26.2 18.1 8.7 'AM' nitrification inhibitor 22.5 16.2 16.2 31.5 18.2 8.4 Methyl bromide fumigation 36.1 34.7 . 25.4 17.7 15.1 8.8 D. P. Wickremaratne A28 — Effect of high soil pH on growth of tea at Brookside Group, Halgran- oya — (1969) An area in Alnwick Division of the above estate where the tea was in very poor condition was brought to our notice. Investigations showed that the pH of the soil in this area was high (7.0) and that the tea was suffering from severe manganese deficiency. The manganese content of the leaf col­ lected from the area was 85 ppm. Two rounds of foliar spraying with man­ ganese sulphate improved the appearance of the tea and the leaf manganese content increased to 160 ppm. But the effect was only temporary because a few months after the manganese spraying the leaves were again showing man­ ganese deficiency symptoms. A short term trial conducted in this area showed that both foliar spraying of a mixture of manganese, aluminium and iron salts and aluminium sulphate treatment of the soil (to lower its pH) increased the manganese content of the leaf and improved the general health of the tea plants. The potassium, phosphorus, calcium, aluminium and iron content of the leaves were, however, not altered significantly by the above treatments. Treatment of the soil with high doses of sulphate of ammonia either alone or together with N-serve did not have any noticeable effect either on the soil pH or the health and appea­ rance of the tea plants. ANNUAL REPORT FOR 1969 39 On manufacturing and tasting of the tea from the four treatments, a higher valuation was obtained for the tea from the foliar spray treatment. This is in agreement with the findings of Wickremasinghe (1968) that spraying of manganese improves the quality of made tea. 1 The full details of this trial together with the results will be published elsewhere. T. Kularatne A29 — Urea foliar application and absorption by the tea plant — (1969) (a) A 3% urea solution was sprayed on two-year-old TRI 2024 plants grown in pots in the glasshouse. Leaves were sampled before spraying and at various intervals after spraying, cleaned with alcohol to re­ move unabsorbed urea and analysed for total nitrogen. The results of two experiments are summarized in Table 18. TABLE 18 — Change in total nitrogen of the leaf following application of urea Hours after spraying 0 1 2 3 24 48 72 96 120 144 Total leaf N ( % ) Experi­ ment 1 2.59 2.82 2.89 2.99 3.09 2.93 3.06 3.02 2.99 2.95 Total leaf N (%) Experi­ ment 2 2.84 — 2.87 — 3.03 3.16 3.23 — 3.19 3.09 The interpretation of results is somewhat difficult due to the possibility of at least part of the urea absorbed by the leaves being translocated to other parts of the plant with time. This difficulty can be overcome only by using nitrogen-labelled urea which was not available to us. The results of this experiment however indicate that the absorption of urea by the plant begins within hours of application. The leaf nitrogen con­ tent increased steadily up to about the third day (72 hours) suggesting that the urea was being absorbed up to this time. (b) In an experiment carried out in the field, a 3 % solution of urea was sprayed to two sets of two-year-old TRI 2024 plants showing nitrogen deficiency symptoms. One set of plants was covered with poly­ thene to prevent the urea being washed off by rain. The second set was left exposed. There was no rain for about 24 hours after spraying of urea. Mature leaf samples were taken before spraying and at different time intervals after spraying, cleaned with alcohol and analysed for total nitrogen. The results are summarized in Table 19. TABLE 19 — Foliar absorption of urea by tea plants under field conditions Time from Total rainfall urea spraying after spraying (hr) Covered plants Exposed plants (inches) 0 2.76 2.76 — 4 2.76 3.40 — 24 2.71 3.16 — 48 2.79 3.24 0.02 72 2.90 2.94 0.20 96 2.94 3.44 0.41 144 2.64 3.02 0.74 40 ANNUAL REPORT FOR 1969 The plants left exposed seem to absorb urea much faster and more effi­ ciently. The total nitrogen in the leaves of the exposed plants fluctuated considerably with time, which could be either due to heterogenity in the samples collected or to the movement of urea (or its bi-products) out of the leaves to the other parts of the plant. But indications are that under the conditions of this experiment urea absorption continued for four days. T. Kularatne A30 — Induced scorch in nursery plants — (1969) An observation trial was carried out on nursery plants to compare the effects of high doses of the nursery mixture T65, sterameal and potassium chloride on nursery plants. High and low doses of T65, sterameal and potas­ sium chloride were applied soilwise to uniform nursery plants in groups of ten, once a fortnight. In addition foliar sprays, with no subsequent washing, of T65 and potassium chloride were also tested. The following observations were made over a period of four months. (a) Foliar application of potassium chloride with no subsequent washing of leaves caused the quickest and severest scorch damage, resulting in defoliation and death of all the plants in the group. Soil applica­ tion of potassium chloride at the higher level caused similar damage as above, but the damage was not immediate. All the plants in this group eventually died. The lower level of potassium chloride caused moderate damage and only two plants out of ten died. (b) Sterameal application also caused damage resembling those obtained . with potassium chloride, but these appeared only about nine weeks after the first application. The low and high levels of sterameal resulted in the death of six and eight plants respectively out of ten. (c) T65 caused the least damage. Some scorch on the young leaves was noticed in the group treated with the lower level of T65 but all plants survived in this group. At the higher level of T65, scorch was somewhat more and eventually two plants died; the plants survi­ ving did not look as healthy as the plants in the group which received the low level of T65. S. Sunderalingam UA3 — Nitrogen (urea) at 3 levels and 3 methods of application on clonal tea at the Passara Sub-station — 3 replicates of 3 2 — (1969) Three blocks of nine plots each were demarcated in an area of clonal tea (TRI 2024, TRI 2025 and TRI 2026). Each block has three plots of each of the three clones. Pre-treatment pluckings were recorded for two and a half months and the treatments were started towards the end of the year. The treatments are three levels of urea, 100, 200 and 300 lb N per acre per year, and three methods of urea application, namely broadcasting, forking and soil injection. L. M. de W. Tillekeratne, A. R. M. Hassim and S. Sundaralingam Acknowledgements . We wish to thank the Managers and Assistants of estates where some of our experiments are located, for their kind co-operation and help. The help of the Statistician in the design of the experiments and the analysis of results is acknowledged. Our thanks are also due to the GAF Corporation, New York and Mitsui Toatm Chemical Inc., Japan for gift of samples of 'Polyclar AT' and 'AM' nitrification inhibitor respectively. ANNUAL REPORT FOR 1969 41 Visits, Lectures and Symposia Dr V. P. Bhavanandan discussed 'Fertilizer use for tea' at the Hewaheta District Planters' Association in October. Publications FERNANDO, L. H., BHAVANANDAN, V. P., WETTASINGHE, D. T. & MANIPURA, W. B. (1969). Fertilizer recommendations for tea in Ceylon — 1969. Tea Q. 40, 129-134. BHAVANANDAN, V. P. & MANIPURA, W. B. (1969). Fertilizer responses of tea in the up-country districts. Tea Q. 40, 135-144. References BAR-AKIVA, A. & STERNBAUM, J. (1965). Nitrate reduction in citrus trees. Plant and Soil 23, 141-144. CHANG, S. C. & JACKSON, M. L. (1957). Soil phosphorus fractionation. Soil Science 84, 133-144. CROOKE, W. M. (1964). The measurement of the cation exchange capacity of plant roots. Plant and Soil 21, 43-49. HASSELO, H. N. (1965). The nitrogen, potassium, phosphorus, calcium, magnesium, sodium, manganese, iron, copper, boron, zinc, molyb­ denum, and aluminium contents of tea leaves of increasing age. Tea Q. 36, 122-136. JACKSON, M . L. (1958). Soil Chemical Analysis — Constable & Co. Ltd., London., 498 pp. KULASEGARAM, S. (1968). Report of the Plant Physiology Division. Rep. Tea Res. Inst. Ceylon 1968, 2, 39-57. PETHIYAGODA, U. (1970). Personal communication. SANDERSON, G. W. & PERERA, B. P. M. (1966). Removal of polyphenols compounds interfering with carbohydrate determinations in plant extracts with and insoluble polyphenol adsorbant. Analyst 9 1 , 335-336. SANDERSON, G. W. & ROBERTS, G. R. (1969). Personal communication. SELVENDRAN, R. R. (1969). Personal communication. SHANMUGANATHAN, N. & FERNANDO, S. R. A. (1967). Some observations on Poria control by soil fumigation with methyl bromide. Tea Q. 38, 311-319. TOLHURST, J. A. H. (1967). Report of the Agricultural Chemistry Division. Rep. Tea Res. Inst. Ceylon 1967, 2, 25-41. WARREN, P. J. WEINBAUM, B. P. & ALLEN, W. M. (1968). Personal commu­ nication. WICKREMASINGHE, R. L. (1968). Report of the Biochemistry Division. Rep. Tea Res. Inst. Ceylon 1968, 2, 93-101. REPORT OF THE AGRONOMY DIVISION Research Officer — W. B. Manipura, BSc, PhD General The Agronomy Division which was merged with the Agricultural Che­ mistry Division in 1965 was reconstituted in October. Messrs S. G. Jaya- sooriya, C. C. Rajasingham and A. Somaratne were transferred from the Agricultural Chemistry Division to the Agronomy Division. The new Division took charge of the field experiments on fertilizer response at St Coombs and other up-country estates. Extension experiments on shade were also trans­ ferred to the Agronomy Division from the Plant Physiology Division. During the year Dr Manipura acted for the Agricultural Chemist for one and a half months. Field Experiments and Trials Fertilizer trials at St Coombs A2 — NPZn, lime at No. 9 Field, St Coombs — (1962) The summarized results for the third year of the second cycle are shown in Table 1. TABLE 1 — Yield response for the 3rd year of second cycle Treatment Yield (lb/acre/year) Ob/acre/year) Replicate 1 Replicate 2 N 150 1859 1873 300 2254 2160 450 2245 2303 Z n S 0 4 0 1977 1915 10 2105 2140 20 2276 2281 LSD (P = 0.05) 269 227 There was a significant response to both zinc and nitrogen but there was no significant response to either the phosphate or the liming treatments. A8 — NPK on clone TRI2024 at No. 8 Field, St Coombs — (1962) The results for the second year of the second cycle are shown in Table 2. As in the first year they have been separated into Group 1, which is high yielding and Group 2, which is low yielding. 42 ANNUAL REPORT FOR 1969 43 Treatment Yield Qb/acre/year) (lb/acre/year) Group 1 Group 2 100 3217 2398 200 4038 3133 300 4412 3080 0 3876 3004 50 3756 3037 100 4035 2571 0 4007 2755 62.5 3967 2820 125 3693 3037 plots 2288 1313 283 257 N p 2 o . K 2 0 LSD (P = 0.05) Nitrogen has shown a significant response up to 300 lb in the better group (Group 1), but in the poorer group (Group 2) there was no significant response above 200 lb. Whereas phosphate gave no significant response in the better group, there was evidence of a yield depression at the highest level (100 lb P20B) in the poorer group. Potash gave no significant response in either group. A10 — N, Kon clone E 727 at Walaha, Tangakelle Group, Lindula — (1965) The summarized results for the first year of plucking of the first experi­ mental cycle are given in Table 3. There was a quadratic response to the levels of nitrogen. TABLE 3 — Yield response for the first year N level Ob/acre/year) 150 300 450 Yield 2685 3302 3210 LSD (P = 0.05) 403 There was no significant response to levels of potash in this experiment. A12 — NPK at No. 3 Field, St Coombs — (1966) Yield data for the first year after pruning were analysed and results are shown in Table 4. TABLE 4 — Yield response for the first year N level (lb/acre/year) 90 180 270 360 450 Yield (lb/acre/year) 628 643 593 588 563 LSD (P = 0.05) 36 LSD (P = 0.01) 49 There was evidence of a highly significant linear depression in yield to the five levels of nitrogen. Phosphate and potash gave no significant responses. S. G. Jayasooriya TABLE 2 — Yield response for the second year of second cycle 44 ANNUAL REPORT FOR 1969 Extension experiments on fertilizer response Yield is expressed as pounds made tea per acre per year, and the period for which the yields have been summarized are quoted separately for each experiment. Fertilizer levels are expressed as pounds per acre per year for nitrogen (N) and potash (K20). In experiments comparing levels of Limbux, only one application at the rate of 0, 1 or 2 tons per acre has been given at the beginning of each experiment. XA1 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels on seedling tea at Tangakelle Group, Lindula — (1965) The tea in this experiment was pruned in July 1969. The summarized results for the first cycle are presented in Table 5. TABLE 5 — Yield response for the period 2.6.66 to 18.7.69 {first cycle) Level of nitrogen Yield (lb/acre/year) (Ib/acre/year) 120 1753 240 1926 360 2078 LSD (P = 0.05) 189 There was a significant linear response to the levels of nitrogen. The yields for the three types of nitrogen were hot significantly different from eaeh other. XA2 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels on seedling tea at May field Estate, Kotagala — (1965) The tea in this experiment was pruned in August 1969. The summa­ rized results for the first cycle are shown in Table 6. TABLE 6 — Yield response for the period 7.6.66 to 27.8.69 {first cycle) Level of nitrogen Yield (lb/acre/year) (lb/acre/year) 120 1976 240 2503 360 2589 LSD (P = 0.05) 78 There was a significant response to the levels of nitrogen, but the yield differences between the three types of nitrogen were not significant. 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 15.10.68 to 30.10.69 were statistically analysed and there was a significant linear response to the levels of nitrogen (Table 7). The types of nitrogen fertilizer did not give any significant effects. A N N U A L R E P O R T F O R 1969 4 5 TABLE 7 — Yield response for the period 1 5 . 1 0 . 6 8 to 3 0 . 1 0 . 6 9 Level of nitrogen Yield (lb/acre/year) (lb/acre/year) 120 2523 240 2882 360 3288 LSD (P = 0.05) 151 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) The experiment was pruned in June 1969. The summarized results for the first cycle of this experiment are shown in Table 8. TABLE 8 — Yield response for the first cycle (4 .6 .66 to 26.6 .69) Level of nitrogen Yield (lb/acre/year) Ob/acre/year) 120 3134 240 3203 360 3296 LSD (P = 0.05) 148 There was a significant linear response to the levels of nitrogen. The types of nitrogen and the levels of potash did not give any significant effects. XA5 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels on VP tea at Ederapolla Group, Bulathkohupitiya — (1965) This experiment was concluded at the end of two experimental cycles. The first cycle consisted of approximately 8 months plucking, and the second cycle consisted of 21 months plucking. Summarized results for the first and second cycle are presented in Table 9. TABLE 9 — Yield response for the first and second cycles Type of nitrogen Calcium ammonium nitrate Sulphate of ammonia Urea LSD (P = 0 . 0 5 ) Level of nitrogen (lb/acre/year) 120 240 360 Yield (lb/acre/year) First cycle Second cycle 2787 2920 3001 109 3212 3297 3331 54 Yield (lb/acre/year) First cycle Second cycle 2809 2937 2962 3242 3311 3289 LSD (P = 0.05) 109 54 In the first cycle calcium ammonium nitrate gave significantly less yield than sulphate of ammonia or urea, but the yield differences between sulphate of ammonia and urea were not significant. Similar trends were also evident in the second cycle for the types of nitrogen. In both cycles a yield response to nitrogen was evident only up to 2 4 0 lb per acre per year. 46 ANNUAL REPORT FOR 1969 XA6 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash on seedling tea at Blair- lomond Estate, Udapussellawa — (1965) The experiment was pruned in October 1969. Yield data were summarized for the first cycle of this experiment, and none of the treatments gave significant yield differences. XA7 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux on seedling tea at Kir- koswald Group, Bogawantalawa — (1966) The experiment was pruned in October 1969. In Table 10 are shown the summarized results for the first cycle of this experiment. TABLE 10— Yield response for the first cycle (17.8.66 to 23.10.69) Level of nitrogen Yield (lb/acre/year) (lb/acre/year) 120 1817 240 2182 360 2345 Level of Limbux (tons/acre) 0 2221 1 2092 2 2031 LSD CP = 0.05) 182 There was a highly significant linear response to the levels of nitrogen. A significant linear depression in yield with increasing levels of Limbux was also evident. The types of nitrogen did not give any significant yield differences. XA8 — Calcium ammonium nitrate, sulphate of ammonia and urea each at three levels in combination with 3 levels of potash on seedling tea at Brunswick Group, Maskeliya — (1966) The experiment was pruned in January 1969. Results summarized for the first experimental cycle are shown in Table 11. There was a significant linear response to the levels of nitrogen. There were no significant differences in yield either to forms of nitrogen or to levels of potash. TABLE 11 — Yield response for the first cycle (18.8.66 to 27.12.68) Level of nitrogen Yield (lb/acre/year) Ob/acre/year) 120 2234 240 2803 360 3132 LSD (P = 0.05) 113 XA9 — Galcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux on seedling tea at Holyrood Estate, Talawakele, — (1966) Yield data were summarized for the period 24.8.68 to 3.7.69 (second year of second cycle). There was no significant response to any of the treatments tested is this experiment. ANNUAL REPORT FOR 1969 47 XA10 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash on seedling tea at Claren­ don Estate, Nanu Oya — (1966) The yield data were summarized for the period 14.6.68 to 26.6.69. There was a significant response to levels of nitrogen (Table 12), but not to the other treatments. TABLE 12 — Yield response for the period 14.6.68 to 26.6.69 Level of nitrogen Yield : (lb/acre/year) (Ib/acre/year) 90 1626 180 1724 270 1911 LSD (P = 0.05) 164 XA13 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash on seedling tea at Ottery Estate, Dickoya — (1966) Yield response to nitrogen for the period 6.7.68 to 22.7.69 (first year of second cycle) are shown in Table 13. There was a significant response to the levels of nitrogen but not to the other treatments. TABLE 13 — Yield response for the period 6.7.68 to 22.7.69 Level of nitrogen Yield (lb/acre/year) (lb/acre/year) 90 847 180 865 270 919 LSD (/> = 0.05) 56 XA14 — Calcium ammonium nitrate, sulphate of ammonia and urea each at three levels in combination with 3 levels of potash on seedling tea at Dickoya Estate, Dickoya — (1966) Analysis of yield data for the period 28.10.68 to 29.10.69 showed that there was a significant linear response to the levels of nitrogen (Table 14). All other treatments failed to give any significant differences in yield. TABLE 14— Yield response for the period 28.10.68 to 29.10.69 Level of nitrogen Yield Ob/acre/year) (lb/acre/year) 90 1320 180 1720 270 1923 LSD (P = 0.05) 166 XA15 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of potash on seedling tea at Koti- yagala Estate, Bogawantalawa — (1966) 48 ANNUAL REPORT FOR 1969 This experiment was pruned in July 1969. Summarized results for the first cycle are shown in Table 15. There was a significant linear response to the levels of nitrogen but the yield differences between types of nitrogen and levels of potash were not significant. TABLE 15 — Yield response for the period 5.1.67 to 15.7.69 (first cycle) Level of nitrogen Yield (lb/acre/year) (lb/acre/year) 90 1612 180 1796 270 2064 LSD (P = 0.05) 226 XA16 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux on seedling tea at Oonoogaloya Estate, Kotmale — (1966) Yield response to levels of nitrogen for the period 6.7.68 to 23.6.69 are shown in Table 16. There was a significant response to 180 lb N per acre but no further response to 270 lb N per acre. There was no significant response to levels of Limbux or types of nitrogen. TABLE 16 — Yield response for the period 6.7.68 to 23.6.69 Level of nitrogen Yield Ob/acre/year) Ob/acre/year) 90 1679 180 1894 270 1870 LSD (P «= 0.05) 94 XA17 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux on seedling tea at Diya­ gama East Estate, Agrapatana — (1966) This experiment was pruned in June 1969. Analysis of yield data for the first cycle of this experiment (3.4.67 to 1.6.69) indicated a significant linear response to levels of nitrogen (Table 17). Types of nitrogen and levels of Limbux did not give any significant yield differences. TABLE 17 — Yield response for the period 3.4.67 to 1.6.69 (first cycle) Level of nitrogen Yield (lb/acre/year) (lb/acre/year) 90 2353 180 2576 270 2882 LSD (P = 0.05) 130 XA18 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels in combination with 3 levels of Limbux on seedling tea at Gona- pitiya Estate, Kandapola — (1966) This experiment was pruned in July 1969. In Table 18 are shown the yield response to levels of nitrogen for the first cycle of this experiment. ANNUAL REPORT FOR 1969 49 TABLE 18 — Yield response for the period 27.5.67 to 24.7.69 (first cycle) Level of nitrogen Yield (lb/acre/year) (lb/acre/year) 90 2560 180 2829 . 270 2905 LSD (J> = 0.05) 256 There was a significant linear response to the levels of nitrogen. Types of nitrogen and levels of Limbux did not give any significant yield differences. This experiment has been concluded. C. C. Rajasingham 1969 Experiments The following fertilizer trials were started during the year and no results are yet available. E76 — NPK on yield and shot-hole borer damage of clonal tea at Carolina Group, Watawala—33 design in 2 replicates — (1969) This experiment is being carried out in collaboration with the Entomologist. MA3 — NPK, Mg and frequency of application on clone TRI 2025 at Ratwatte Estate, Ukuwela—35 factorial — (1969) This experiment is being carried out in collaboration with the Mid-Country Scientific Officer. UA6 — NPK, Mg on clonal tea at Agratenne Substation, Passara—34 design — (1969) This experiment is being carried out in collaboration with the Uva Scien­ tific Officer. Experiments on spacing and bringing into bearing A9 — Clonal spacing at Nos 2 and 7 Fields, St Coombs — (1964) The plots were pruned in August, at the end of five years from planting. In Table 19 are shown the yield trends for the final year of the cycle. TABLE 19 Yield response for the fifth year of first cycle Initial N treatment Present N treatment Yield (lb/acre for 15 months) (lb/acre/year) (lb/acre/year) 16.6 240 2066 83.3 240 2242 150.0 240 2402 LSD (P = 0.05) 176 Clone TRI 2024 2399 DT 1 2327 ... TRI 777 1983 LSD {P = 0.05) 176 Spacing in inches (in the row) 14 2283 28 2205 42 2220 LSD (2> = 0.05) NS 50 ANNUAL REPORT FOR 1969 Mean stem diameter (cm) Spread in the row (in) Spread between rows (in.) Shoot number per plant Fresh weight of tipped shoots Ob per plot) Mean stem diameter (cm) Spread in the row (in.) Spread between rows (in.) Shoot number per plant Fresh weight of tipped shoot (lb per plot) Mean stem diameter (cm) Spread in the row (in.) Spread between rows (in.) Shoot number per plant Fresh weight of tipped shoots (lb per plot) Bending Cut Cut and LSD (P = only only bent 2.19 1.69 2.05 0.20 25.6 17.9 24.2 2 .2 35.1 20.0 28.1 2.2 28.5 23.0 28.5 3.9 16.0 3.8 5.3 1.3 Spacing in the row(in.) 10} 21 42 LSD (P = 1.90 1.98 2.06 NS 17.3 23.1 27.2 2 .2 28.6 27.6 27.0 NS 24.7 25.4 29.9 3.9 5.6 8.0 11.5 1.3 Clones D T I TRI 2142 TRI 2025 LSD (P = 1.83 2.04 ..2.07 0.20 19.9 22.1 25.7 2 .2 23.4 25.8 34.1 2 .2 23.6 25.5 30.9 2.2 6.0 8.2 10.9 1.3 0.05) 0.05) As in the previous year, this experiment received uniform fertilizer treatments in the fifth year from planting in order to evaluate the residual effects of varying levels of a NPK mixture applied during the first 15 months from planting. As evident from Table 19, the residual effects of the initial fertilizer treatments were present even in the fifth year. Clone TRI777 gave significantly lower yields than TRI 2024 or DT 1. The spacings indicated in the Table are distances between plants in the row, rows being four feet apart. There were no significant yield differences between spacing treatments in the fifth year. A15 — Bringing into bearing and spacing of clonal tea No. 3 Field, St Coombs — (1967) The treatments in this experiment were described in detail in the Annual Report of the Agricultural Chemistry Division for 1968. Plants were tipped at 18 in. in May and brought into plucking in July. At tipping stage the following growth measurements were made:- 1 — Mean stem diameter at ground level 2 — Spread per plant in the row at tipping level 3 — Spread per plant between rows at tipping level 4 — Shoot number per plant at tipping level 5 — Fresh weight of tipped shoots per plot. The summarized results of the above assessments are shown in Table 20. TABLE 20 — Effect of methods of bringing into bearing and spacing on growth of clonal tea ANNUAL REPORT FOR 1969 51 'Bending only' treatment and the treatment where the plants were given an early cut and bent subsequently gave greater stem diameter, greater spread of plants in the row, and between rows, and greater shoot number per plant than the treatment where the plants received two cuts. 'Bending only' resulted in the highest shoot weight per plot and 'cut only' treatment gave the lowest shoot weight, while the 'cut and bent' treatment was intermediate. Stem diameter at ground level and the spread of plants between rows were unaffected by spacing treatments. Spread of plants in the row increased with increasing plant spacing in the row. The weight of tipped shoots per plot decreased with increasing spacing of plants in the row. Plants spaced 42 in. in the row had significantly greater shoot number per plant than plants spaced at 21 in. or 10\ in. in the row. In all the growth assessments made, clone TRI 2025 was superior to TRI 2142, which in turn was better than clone DT 1. S. G. Jayasooriya 1969 Experiments MA3 — Clone x spacing x bringing into bearing at the Mid-Country Station, Kandy—33 design in 2 replicates — (1969) This experiment was laid down late in the year and it is described in the Report on the Mid-Country Station. A23 — Four clones each at 5 spacings in Nos 3 and 5 Fields, St Coombs — split plot design in 3 replicates — (1969) Four clones, TRI 2027, K 150, DN and N 2, each at five spacings corres­ ponding to 2420, 3630, 5440, 7260 and 9680 plants per acre are being tested in this experiment. Clones are allocated to main plots and spacings to sub-plots. This trial was laid down in July. A24 — Three clones each at 3 spacing patterns in No. 5 Field, St Coombs — Split plot design in 4 replicates — (1969) Three clones, TRI 2027, DN and N 2, are studied in relation to three spacing patterns, namely 3 ft x 3 ft, 4£ ft x 2 ft and 6 ft x If ft, all giving a planting density of 4840 plants per acre. Clones are allocated to the main plots and spacing patterns to the sub-plots. This trial was laid down in July. S. G. Jayasooriya Shade experiments A13 — Three levels of N on 3 clones with 3 levels of shade at No. 3 Field, St Coombs — (1966) This experiment will be brought into plucking in June, 1970. UA2 — Shade x clone x bringing into bearing—Agratenne — (1966) This experiment was laid down in late 1968 to compare three levels of shade, five clones and three methods of bringing into bearing. The three levels of shade are :—- 1 — No shade 2 — Gliricidia maculata spaced 7 ft x 20 ft 3 — Gliricidia maculata spaced 7 ft x \0l 52 ANNUAL REPORT FOR 1969 Each main plot receiving shade treatments are sub-divided into five plots to be allocated to the five clones given below. 1 — 2023 2 — 2025 3 —DN 4 — CV5B1 5 — KEN 16/3 Each of the clonal plots are further sub-divided to take the following bringing-into-bearing treatments :— 1 — Bending followed by cut-across at 12 in. at one year from planting 2 — Cut three months after planting at 6-9 in., and one year after planting at 12 in. 3 — Plants allowed to grow freely for one year and cut across at 12 in. Initial bringing-into-bearing treatments were completed by the end of the year. No results are yet available for publication. UA7 — Shade x clone x bringing into bearing, Aislaby Estate, Bandarawela— split plot design with 4 replicates — (1969) This experiment was laid down late in the year and no results are available. Extension experiments on shade x level of nitrogen in up-country estates The experiments on shade and fertilizer nitrogen conducted by the Plant Physiology Division in collaboration with the Advisory Division were transferred to the Agronomy Division during the year. Previous results of these experiments were presented in the Report of Plant Physiology Division for 1965, 1966, 1967 and 1968. All experiments reported are carried out on seedling tea. XPH1 — Nitrogen at 4 levels with shade vs no shade as the main treatments at Liddesdale Group, Halgranoya — (1965) The experiment is now in its second cycle. The summarized results for the period 27.8.68 to 9.8.69 are presented below. XPH2 — Nitrogen at 4 levels with shade vs no shade as main treatments at Rothschild Estate, Pussellawa — (1965) The experiment is now in its second cycle and the results for the period 23.10.67 to 9.1.70 are presented below. XPH3 — Nitrogen at 4 levels with shade vs no shade as main treatments at Mayfield Estate, Kotagala — (1965) The experiment is in the second cycle. The summarized results for the period 19.8.68 to 13.12.69 are given below. XPH4 — Nitrogen at 4 levels with shade vs no shade as main treatments at Hauteville Estate, Agrapatana — (1965) ANNUAL REPORT FOR 1969 53 TABLE 21 — Effect of shade vs no shade on yield Experiment Location (lb/acre/year) Shade No shade LSD (J» = 0.05) XPH1 Liddesdale 1549 1795 150 XPH2 Rothschild 1484 1562 67 XPH3 Mayfield 1474 1529 76 XPH4 Hauteville 1641 1768 89 XPH5 Blairlomond 2324 2439 118 XPH9 Brunswick 2136 2174 NS XPH10 Morar 2028 2238 75 XPH12 Oonoogaloya 1566 1524 NS In six out of eight experiments yield without shade was significantly greater than with shade. In the remaining two there were no significant yield differ* ences with and without shade. The tea was pruned in October, 1969. The summarized results for the first cycle (25.2.67 to 12.10.69) are presented below. XPH5 — Nitrogen at 4 levels with shade vs no shade as main treatments at Blairlomond Estate, Udapussellawa — (1966) The tea was pruned in October 1969. The summarized results for the first cycle (10.9.66 to 30.9.69) are given below. XPH9 — Nitrogen at 4 levels with shade vs no shade as main treatments at Brunswick Group, Maskeliya — (1966) The experiment is in the second cycle. The summarized results for the period 5.9.67 to 29.11.69 are given below. XPH10 — Nitrogen at 4 levels with shade vs no shade as main treatments at Morar Estate, Bogawantalawa — (1966) The experiment is yet in the first cycle. The results presented below are for the period 18.6.67 to 12.12.69. XPH12 — Nitrogen at 4 levels with shade vs no shade as main treatments at Oonoogaloya Estate, Kotmale — (1966) The experiment is yet in its first cycle. The summarized results for the period 31.7.67 to 26.1.70 are given below. In Table 21 are presented the effect of shade on yield and in Table 22 the effect of levels of nitrogen on yield. The periods for which yield has been summarized are mentioned under each experiment. 54 ANNUAL REPORT FOR 1969 TABLE 21 — Effect of level of nitrogen on yield (lb/acre/year) Experiment Location NO N l N2 N3 LSD (P = 0.05) XPH1 Liddesdale 1395 1534 1888 1870 213 XPH2 Rothschild 1473 1476 1635 1508 96 XPH3 Mayfield 1253 1580 1552 1620 108 XPH4 Hauteville 1450 1582 1842 1944 126 XPH5 Blairlomond 2241 2428 2410 2448 168 XPH9 Brunswick 1719 2085 2285 2531 144 XPH10 Morar 1788 2038 2252 2456 106 XPH12 Oonoogaloya 1133 1508 1736 1804 76 The levels of nitrogen in all experiments except XPH5 are 0, 120, 240, 360 lb nitrogen per acre per year for NO, Nl, N2 and N3 respectively. In XPH5 the levels of nitrogen are 100, 200, 300 and 400 lb nitrogen per acre per year for NO, Nl, N2 and N3 respectively. In the experiments where zero nitrogen levels are present, reasonable yield levels were still evident, suggesting strong residual effects of previous high levels of nitrogen application. Nitrogen application in general had a promotive effect on yield in all experiments. In Experiments XPH1, XPH3, XPH4, XPH9 and XPH10 there was a significant linear response to nitrogen. In XPH5, where 100, 200, 300 and 400 lb N per acre per tested there was a significant yield response only up to 200 lb. In Experiment XPH2 a significantly cubic response to nitrogen was evident where the yield rises slowly at first and then sharply from Nl to N2 and then a decline at N3. In Experiment XPH12 the yield response to nitrogen was quadratic indicating a smaller response to nitrogen at high levels than at low levels. Interaction of shade and levels of nitrogen was evident in Experiment XPH4, indicating a greater response to nitrogen without shade than with shade. There were no shade x nitrogen interactions in the other experiments. A. S. B. Gomez & S. G. Jayasooriya Rehabilitation experiments A16 — Rehabilitation Experiment Nos 11 and 13 Fields, St Coombs — (1967) The soil rehabilitation treatments in this experiment are :— 1 — Rehabilitation for two years with Guatemala grass 2 — Rehabilitation of one year with Guatemala grass 3 — No rehabilitation 4 — No rehabilitation but fumigation with methyl bromide at the rate of 1 lb per 200 sq. ft. These treatments are applied to main plots and each main plot is sub­ divided into six plots to receive all combinations of the following treatments :— ANNUAL REPORT FOR 1969 55 Mulching— 1. Mulching twice a year 2. No mulching Nitrogen — 1. 45 lb N per acre per year 2. 90 lb N per acre per year 3. 135 lb N per acre per year. After the completion of the initial rehabilitation treatments, the plots were planted with clone TRI 2025 in September 1969. A18 — Guatemala grass, Mana grass and Crotolaria anagyroides each at 3 levels of nitrogen as soil rehabilitation crops at No. 5 Field, St Coombs — (1968) Soil reconditioning with the three crops will be carried out for a period of two years before tea is planted. No results are available for publication. A19 — Rehibilitation vs none at No. 3 Field, St Coombs — (1968) The plants were tipped at a height of 12 in. in July. The dry weights of leaf and stem and the total dry weight of tipped shoots per plant are shown in Table 22. TABLE 22 — The dry weight of leaf, stem and the total dry weight of tipped shoots per plant (g) Leaf dry wt Stem dry wt Total dry wt 2-year rehabilitation 30.7 15.4 46.1 No rehabilitation (fumigated) 48.3**» 31.1*** 79.4*** •••Significant at P < 0.001 Plots fumigated with methyl bromide gave significantly greater leaf, stem and total dry weights of shoots per plant than the plots rehabilitated with Guatemala grass for two years. Weed assessments showed that plots fumigated with methyl bromide were generally free of weeds for about one year after fumigation, while there was considerable weed growth in plots rehabilitated with Guatemala grass. At subsequent assessments the amount of weeds ia the fumigated plots was about half that of plots rehabilitated with Guatemala grass. The experiment will be brought into plucking at the end of two years from planting. A. Somaratne & S. G. Jayasooriya 1969 Experiments MA2 — Three periods of rehabilitation, 3 types of rehabilitation crop, and 3 types of ground cover during early growth of replanted tea—33 design in 2 replicates — (1969) This experiment was started at Mid-Country Station, Kandy, late in the year. Young tea experiments Experiment A21 was concluded. A20 — Mulching on young tea at No. 3 Field, St Coombs — (1967) 56 ANNUAL REPORT FOR 1969 This experiment was concluded and the results obtained were published in The Tea Quarterly of December 1969. Soil management studies A25 — Mulching and cover crops in young tea—6 treatments in 4 replicates — randomized block design — (1969) This experiment was laid down during the year to compare the effect of the following treatments on soil erosion, soil moisture and the growth of young tea. 1 — Bare — clean weeded 2 — Guatemala grass mulch 3 — Mana grass mulch 4 — Crotalaria sp. as a cover crop 5 — Eragrostis curvula as a cover crop 6 — Weeds as a cover crop. No results are available for publication. A26 — Mulching and cover crops on surface runoff and soil erosion—unrepli- cated — (1969) Preliminary experiments carried out in small plots showed that surface runoff and soil erosion were markedly reduced in mulched plots, compared with bare, clean weeded plots. Observations were made during the month of April when a considerable number of storms of high rainfall intensity, occurred. With large scale replanting, soil erosion could be a serious problem during the first two years of growth of replanted tea, when the soil is exposed. The methods by which an effective ground cover may be maintained during the early stages of the growth of tea is by mulching or by growing a suitable cover crop between tea rows. In order to make further observations on this problem, an unreplicated trial was laid down during the year to study the effect of (a) cover crop, (b) mul­ ching, and (c) keeping the land bare and clean weeded, on runoff and soil losses. No results are available for publication. C. C. Rajasingham The following experiments were laid down during the year at Agratenne Substation, Passara in collaboration with the Uva Scientific Officer. No re­ sults are available for publication. UA4 — Size of hole, level of phosphate and clones—33 design in 2 replicates — (1969) UA5 — Mulching, forking and level of nitrogen—3s design in 2 replicates — (1969) Chemical control of weeds Experiment Wll was concluded. ANNUAL REPORT FOR 19$ W12 — Couch control — (1968) The initial treatments in this trial were modified and the following treat­ ments were tested :— 1 — Amitrole at 2.5 lb per acre 2 — Amitrole at 5 lb per acre 3 — Dalapon at 5 lb per acre 4 — Dalapon at 10 lb per acre 5 — Control. The first application of these treatments was given in September 1969. Dalapon caused severe scorch of Couch grass and there was no large difference between the two rates of application. Amitrole was more effective at the higher rate than at the lower rate but the control obtained with amitrole in general was less than with dalapon. Three months after the initial spraying dalapon- sprayed plots did not show any regeneration or new growth, but the amitrole- sprayed plots showed some new growth at both rates of application. All plots were clean weeded by cutting plants at ground level. Further applica­ tion of above treatments will be carried out when plants show sufficient new growth. W13 — Gramoxone and diuron separately and in combination on weeds in VP tea — (1968) This experiment was started in September 1968 to test the effect of Gra­ moxone and diuron separately and in combination on weeds in clonal tea. The experiment was carried out for one year from September 1968 to September 1969. Assessments of weed growth were made by visual scoring monthly. The different combinations of chemicals were applied on three occasions, namely September 1968, January 1969 and July 1969. The summarized results of the percentage weed growth are shown in Table 23. Because of the large initial variation in weed growth between plots, the assessments made after the first application did not show marked diffe­ rences in weed growth between the treatments tested. After the second appli­ cation in January, assessments were made in February and it was evident at this stage that there were no large differences between the diuron and Gra- moxone-treated plots at either rate. The combinations of Gramoxone and diuron were superior to the two chemicals applied alone. During the dry months of March and April there was very little weed growth and no differences were evident between treatments. During the wet months of May to Sep­ tember, plots treated with diuron either alone or in combination with Gra­ moxone showed much less weed growth than plots treated with Gramoxone only. W14 — Diuron, Simazine and Gramoxone on VP tea — (1968) The following treatments were tested on the yield of clonal tea (clone TRI 2142) :— 1. Diuron at 1 lb per acre per application 2. Diuron at 3 lb per acre per application 3. Simazine at 1 | lb per acre per application 4. Simazine at 3 lb per acre per application 5. Gramoxone at 1 pint per acre per application 6. Control—hand weeded. TABLE 23 — Effect of Gramoxone and diuron on weed growth Visual scores on precentage weed growth Treatment* (100 = heavy weed infestation; 0 = no weed infestation) Gramoxone (pints/acre) Diuron (lb/acre) Oct. 1968 Nov. 1968 Dec. 1968 Jan. 1969 Feb. 1969 May 1969 June 1969 July 1969 - 1 33 32 28 33 13 15 26 18 - 2 45 25 20 35 13 15 36 20 4 - 35 30 38 60 12 43 86 47 I - 36 28 40 50 10 50 90 32 i 1 26 13 18 30 2 15 46 20 i 2 38 23 33 38 5 15 43 25 1 1 43 16 20 28 2 12 33 10 1 2 32 15 21 42 2 12 30 10 * Sprayed on three occasions — Sept. 1968, Jan. 1969 and July 1969 N o assessments were made during March and April (1969) due to poor weed growth A N N U A L R E P O R T F O R 1969 59 Four applications of the above treatments were given during the first year after pruning. There were no significant differences in yield between treat­ ments during this period. 1969 Experiments W15 — Five chemicals each at 2 levels compared with hand weeding on the yield of seedling tea—3 randomized blocks — (1969) Plots have been laid down and pre-treatment plucks are being carried out. W16 — Control of Artemisia vulgaris — (1969) Artemisia vulgaris (wild chrysanthemum) is a common weed in the up- country estates which is not effectively controlled by chemicals such as Gra­ moxone and diuron which are commonly used at present. In observation trials carried out in small plots 2, 4-D sodium salt at 1 and 2 lb per acre and Gramoxone at J pint per acre were tried on this weed. Gramoxone scorched the foliage severely but the plants regenerated in about one month. At the 1 lb rate 2, 4-D had little effect, but at the 2 lb rate it gave some control up to two months after which the plants regenerated. In the second observation trial, 1 lb diuron per acre, 2 lb 2, 4-D sodium salt per acre, a mixture of 1 lb diuron and 2 lb 2, 4-D sodium salt per acre, and 1 lb Amitrole per acre were sprayed. In this trial, diuron had no appre­ ciable effect, but all other treatments gave effective control for about two months. From these observations it appears that Amitrole and 2, 4-D would give effective control of this weed for short periods but more effective chemicals would have to be evaluated for long-lasting control. A. Somaratne Crop Diversification One acre of each of the following timber species was planted in Nos 4 and 5 Fields of St Coombs. 1. Eucalyptus saligna 2. Eucalyptus camuldulensis 3. Pinus caribea 4. Dendrocalamus strictus The first three species were planted in standing tea and Dendrocalamus strictus in an area where the tea has been uprooted. Acknowledgements Thanks are due to Superintendents of estates where experiments are located, for their kind co-operation and help in carrying out the experiments. The assistance given by the Statistician in the design and analysis of experiments is greatefully acknowledged. Our thanks are also due to the Agricultural Chemist for providing laboratory facilities. Publications BHAVANANDAN, V. P. & MANIPURA, W. B. (1969). Fertilizer responses of tea in the up-country districts. Tea Q. 40, 135 - 144. FERNANDO, L. H., BHAVANANDAN, V. P., WETTASINGHE, D. T. & MANIPURA W. B. (1969). Fertilizer recommendations for tea in Ceylon. Tea Q. 40, 129-134 . MANIPURA, W. B., SOMARATNE, A. & JAYASOORIYA, S. G. (1969). Some effects of mulching on the growth of young tea. Tea Q. 40 ,153 - 1 5 9 . kfiPORf OF THfi PLANT PHVStOLOGV DIVISION Plant Physiologist — U. Pethiyagoda, BSc, PhD, DIC General Dr U. Pethiyagoda returned to the Institute in March after completion of one year at Rothamsted Experimental Station, UK. Mr A. R. Sebastiampillai was awarded the PhD of the University of Reading for his thesis on "The production and cytology of polyploid strawberries" and returned to his duties in April. Messrs S. Kandiah and S. Nagarajah continued their postgraduate studies at East Mailing Research Station, UK and the Australian National University, Canberra respectively. Mr A. S. B. Gomez was assigned the duties of assisting the Advisory Service from January and spends his time exclusively on this task. Mr S. Kumaraguneratnam joined as Technical Assistant in March and resigned his post in June. Mr A. Kathiravetpillai was transferred from the Division of Entomology as a Technical Assistant, in December. The Plant Physiologist was a member of the TRI delegation to the Twenty Fourth Tocklai Conference held at Jorhat, Assam in November and also visited some tea areas in Assam, Dooars and Darjeeling. He was also elected President of Section B (Agriculture and Forestry) of the Ceylon Association for the Advancement of Science for the coming year. An increasing volume of advisory work had to be undertaken by members of the Division. Laboratory Investigations Growth of tea in sand culture Studies on the mineral nutrition of tea Very satisfactory progress continued to be made in studies on tea plants grown in sand culture in the glasshouse. Several experiments were carried out or initiated during the year and the main observations are summarized below. Aluminium in the nutrition of tea Large amounts of aluminium are normally absorbed by tea plants and are detectable in the leaves. In three experiments reported in the last two Annual Reports, there was no response of tea plants to different levels of aluminium supply. Analysis of leaf samples from two of these trials revealed relatively high levels of alumi­ nium, even at presumed zero levels of supply—apparently entering as a con­ taminant. It is suspected and this may originate from the sand, nutrient solutions or metallic components in the construction of the glasshouse. A fourth trial, mentioned in the Annual Report for 1968 was concluded during the year with an assessment of the plants. While there was evidence of a slight depression of growth at the zero level of aluminium supply, there were no differences between plants receiving 1, 2, 4 and 8 ppm of aluminium in the nutrient solutions. Thus 1 ppm of aluminium in the nutrient solutions seems adequate to meet the needs of tea plants. 60 ANNUAL REPORT FOR 1969 61 In the experiment mentioned in the last report and where the levels of aluminium were 0, 10, 20 and 40 ppm, no growth differences were apparent and it was decided to employ these plants for the purpose of observing whether death of feeder roots can be detected after pruning (see below). Leaf samples from the aluminium and fluorine trial have been analysed for the two elements by the Agricultural Chemistry Division and the results are discussed in the report of that division. S. Krishnapillai & Agricultural Chemistry Division Comparison between nitrate and ammonium as forms of nitrogen for tea This experiment which was described in the Annual Report for 1968 was concluded during the year. The development of certain symptoms in plants at the two extreme ends of the treatment scale was noted in the last report. At the final assessment, comprehensive growth assessments were carried out. It was very clear from all the different measures of growth, that the plants receiving 60, 70, 80 or 90% of their nitrogen as nitrate had grown best, while those receiving 0, 10 or 20% of their nitrogen in the nitrate form performed very poorly. The 30,40,50 and 100 % as nitrate, treatments fared only moderate - ly well. It seems clear that tea plants' make best use of nitrogen when pro­ vided with a mixture of nitrate and ammonium forms, with the former pre­ dominating. It may be noted here that although sulphate of ammonia is the commonest form of nitrogen supply, there is ample evidence that transforma­ tion to the nitrate form does normally occur in the soil. The conditions promoting an optimal degree of change would evidently have a bearing on response of tea to nitrogen fertilizing. It is to be noted that under the condi­ tions of this experiment, where the sand is likely to function as a relatively inert medium, this type of transformation would be minimal. In all our nutritional studies in the glasshouse, two thirds of the nitrogen supplied was as nitrate and the other one third as ammonium. The results of this experiment support this intuitive selection of proportions. At assessment, leaf samples were analysed by standard procedures, to determine the amounts of nitrogenous compounds present. Unassimilated nitrate and ammonium nitrogen, amino-acid, amide, protein and caffeine nitrogen were among the fractions estimated. The results can be expressed in two ways—either as the content per unit weight of leaf or as content per plant. The second basis of expression is justified by the variation in the growth of plants depending on treatment. The contents of ammonium and nitrate nitrogen in the leaf follows the pattern of supply of these two components in the nutrient solution. Thus the plants receiving more nitrate tend to contain more of this form. Likewise, plants receiving mainly ammonium have more of this form, although the trend is not as marked in this case. Nitrate is converted to the ammonium form within the plant and this in turn is further elaborated into amino-compounds. The presence of relatively high nitrate in plants receiving only ammonium nitrogen is somewhat puzzling. In respect of amide, amino-acid, caffeine, protein and total nitrogen, the trend is in accord with the total growth of the plants in the particular treatments. As these compounds are all biologically important nitrogenous compounds, this is consistent with a better utilization of nitrogen and consequent better growth of the plants in the favourable treatments. 62 ANNUAL REPORT FOR 1969 An attempt made to draw up an approximate balance sheet for nitrogen supplied and amounts detected in the plant, revealed that amounts detectable in the leaves ranged from about 7 % to about 25 % of the total supplied. The latter figure is exceptionally high and is an encouraging indication that the levels of supply are not wasteful. The lower efficiencies are in the treatments where ammonium nitrogen predominates and in the treatments with an exclu­ sively nitrate supply. In all such cases, it was evident that root growth was also limited. While four of the five replicates in the experiment were used in the assess­ ment, the fifth was pruned at a height of 16 inches, to determine whether the composition of the nitrogen supply affected recovery. There was no clear indication that it did so. S. Krishnapillai Pruning and death of feeder roots In view of the lack of apparent response to differential aluminium supply, it was decided to utilize the plants from one experiment on levels of aluminium for an observation trial on pruning effects. It has often been suggested that death of feeder roots follows pruning of tea. The ease with which the entire root systems from plants in pots of sand can be recovered and examined, presents a convenient opportunity for directly observing such an effect. Accor­ dingly ten pots, each containing two plants from open-pollinated (clone TRI 2024) seed were employed. One plant in each pot was to be "clean-pruned" while the other was provided with a few "lung branches" originating below the pruning level of 16 inches. Two pots comprised a treatment. The pruning was so timed that when the plants were all examined in mid-December, the treatments were unpruned, pruned 4, 8, 10 and 12 weeks previously, respect­ ively. In none of the treatments could dead feeder roots be observed. This result is surprising in view of previous evidence. It would appear that condi­ tions within the sand prevent the death of these roots. S. Krishnapillai New experiments in the glasshouse Trace elements deficiencies Success in obtaining symptoms of manganese deficiency was recorded in the Annual Report for 1967. Incidentally, it has been encouraging to see identical symptoms on tea in the field or an estate with a problematic "high pH" area. An attempt is now being made to obtain symptoms of some other trace elements deficiencies—namely for boron, zinc, copper, molybdenum and chlo­ rine. Plants of TRI 2025 were initially supplied with a nutrient solution lacking in all five of the above trace elements. Groups of eight plants were then maintained with solutions lacking in one or other of the elements listed. Boron deficiency symptoms were extremely rapid in their appearance. The effects were evident within about two months, in particular, death of the terminal bud and stoppage of growth. The other main symptoms were the development of small translucent "oil spots" on the leaves—rather reminiscent of those appearing in the early stages of calcium deficiency. This symptqni is however apparently transitory. A striking feature is the excessive develc-p1 ment of corky tissue. This takes the form of mounds of cork on the upper side ANNUAL REPORT FOR 1969 63 of the leaf stalks and streaks extending downwards along the stem. The veins on the upper and lower surface of the leaves, literally crack open along their lengths due to cork development. No symptoms of deficiency of the other trace elements have yet appeared. S. Krishnapillai Foliar analyses in the diagnosis of nitrogen and potassium deficiency An attempt is being made to define critical levels of nitrogen and potassium in leaf samples of plants of TRI 2025 grown in sand culture in the glasshouse. It is hoped to determine the levels of these elements that are associated with varying degrees of deficiency or excess and so furnish information on the interpretation of foliar analysis data in relation to growth performance. Diffe­ rent types of leaves are also sampled to assist in deciding upon the optimal leaf type for analysis. Eleven combinations of various levels of nitrogen and potassium, ranging in each case from zero to four times the amount normally supplied are the treatments, replicated four times. First samples taken when nitrogen deficiency symptoms were well advanced in the zero—N treatment have been analysed. Further samples will be taken at appropriate times. S. Krishnapillai Growth in relation to strength of nutrient solution Hewitt's nutrient solution has been employed in our experiments on sand culture of tea. Supply of this solution at half the normal recommended con­ centration seems adequate to support healthy growth of tea plants. An experiment where the standard solution is compared at £, \, 2/3, 1, \ \ and 2 times the concentration that is normally employed in our studies, is simply designed to indicate the optimal level of supply. The plants are nearly ready for assessment. S. Krishnapillai Growth in relation to pH of nutrient solution Early work by Gadd (1928) indicated that the pH of the growth medium (in water culture experiments) affected the growth of young tea plants. An experiment was commenced with TRI 2025 in sand culture, to assess the effect of varying the pH of the standard nutrient solution. By using appropriate amounts of either sulphuric acid or potassium hydroxide, six pHs with the extreme treatments being 2.5 and 8.0 were obtained. Checks on the pH of the effluent however confirm the difficulties of con­ trolling the pH in sand culture experiments. S. Krishnapillai biteractions between potassium and sodium Symptoms caused in clone CY 9 by deficiency of potassium were briefly described in the Annual Report for 1967. In an experiment commenced 64 ANNUAL REPORT FOR 1969 recently, it is desired to determine whether the simultaneous provision of sodium under conditions of potassium deficiency mitigates or aggravates the symptoms. The clone employed is TRI 2025 and the six treatment combina­ tions are K^Na,,, K^Na^ K<,Na70, K^Na,,, K4 9Na5 0and K 9 gNa 1 5. The figures represent parts per million of the element in the nutrient solution. It appears that this clone (as also TRI 2024 mentioned in the Annual Report for 1968) shows a marginal yellowing of the younger leaves when no potassium is supplied. Scorching of the tips and margins of the older leaves is a symptom which appears to be aggravated with increase in the level of supply of sodium. Leaf analyses for potassium and sodium are to be carried out. S. Krishnapillai Field Experiments and Trials The following experiments were concluded during the year :— PH 13, PH 20, PH 24 and PH 28. The management of the Extension Experiments on shade vs fertilizer has been handed over to the Agronomy Division. PH 3 — Growth analysis — (1963) One further assessment was carried out during the year. The relevant treatments were pruned in August and the tea is now back in plucking. In accordance with the design of this experiment, half the number of plots that were plucked in the first cycle will now be unplucked in the second. Similarly half of the plots that were unplucked in the first will be plucked in the second cycle. General comments on the behaviour of the plants in relation to treatments were given in the Annual Report for 1968. The voluminous data assembled during the first completed cycle of this experiment await analysis. At the time of the first prune, two bushes from each of the three treatments (free growing, bent but unplucked, bent and plucked) from each of the two clones, were carefully excavated. This was done in six-inch layers for a depth of 30 inches, below which negligible amounts of root were present. The roots in each layer of soil were carefully recovered and separated into "coarse" and "fine roots" for fresh and dry weight determinations. There were no marked differences in root distribution with treatment. Roots of the free-growing treatment were greater in quantity and had reached slightly greater depths. Plucking has had little effect. H. B. Wijetunga & S. Wimaladhanna PH 5 — Mulching — (1965) The tea in this experiment was pruned in July. The yields in the last complete cycle confirmed the earlier results on effects of nitrogen level and mulch. The largest benefits resulted from the use of dadap and tea leaves as mulch while Grevillea and mana also gave smaller yield increases. The Agricultural Chemistry Division sampled some of the plots for deter­ minations of organic matter and pH. There are reports in the literature of an ANNUAL REPORT FOR 1969 65 increase in soil pH with the application of certain types of mulch. The results of the analyses are presented in the Report of the Agricultural Chemistry Division. After pruning, gypsum blocks were buried at depths of 12, 24 and 36 inches, in one set of plots with different mulching treatments. The gypsum blocks have taken a long time to stabilise and variations in the readings are just becoming evident. H. B. Wijetunga & S. Wimaladharma PH 12 — Hakea saligna as a shelter belt plant — (1965) This observation trial continues. PH 14 and PH 15 — Total available carbohydrate (TAC) levels and recovery from pruning — (1965) No studies were undertaken on this subject during the year. PH 25 — Growth retardants on tea — (1967) Three growth retardants Cycocel (2—chloroethyltrimethyl-ammonium chloride 50%), B-9 (N—dimethylaminosuccinamic acid 98% WP) and Regu- lox W (maleic hydrazide assumed to be 100%) were tested, each at three appro­ priate levels, along with an unsprayed control. Two clones DT 1 and TRI 2025 were used, with each treatment replicated four times. The compounds were administered as a single drenching spray on the foliage of 2-month old cuttings. Unfortunately, the subsequent growth of all the plants (including controls) has been very irregular and detailed assessment may prove inconclusive. How­ ever, Cycocel (at 5% and 2% v/v) and B-9 (at 1 % and 0.5% w/v) appear to influence growth. This merits further study. S. Wimaladharma PH 26 — Studies on banji — (1967) Satisfactory progress was made in the further analysis of banji in tea and a second paper "Roots as the source of a stimulus associated with the growth of dormant buds" has been published in The Tea Quarterly (Kulasegaram 1969). Studies are now being undertaken to assess the relative importance of nutritional and hormonal factors as components of the "root stimulus" in growth and dormancy. Preliminary results obtained so far indicated that the plants maintained at double the recommended dose of T 65 nursery fertilizer had a lower percentage of dormant terminal buds than those maintained at the recommended dose of T 65 or those in which T 65 application was suspended. Where application of T 65 was suspended the plants remained dormant for a longer period and had a higher percentage of dormant terminal buds. Plants at the lower levels of nutrition appeared to respond better to hormones than plants maintained at the higher levels of nutrition. The experiment is in progress and further results are awaited before the data can be fully analysed. S. Kulasegaram & A. Kathiravetpillai PH 29 — Growth factors and recovery from pruning — (1967) No further studies were undertaken on this subject during the year. 66 ANNUAL REPORT FOR 1969 1969 Experiments Studies ou pruning and recovery PH 30 — Damage to developing buds by salt sprays — (1969) Evidence has been presented earlier (Pethiyagoda 1966) to suggest that excess fertilizers taken up by the tea plant in the early stages of recovery from pruning are damaging. During the course of the year several Superintendents have confirmed that moving fertilizer applications away from pruning has improved recovery. In this experiment, solutions of a number of salts were sprayed on the frames of bushes of TRI 2024 at five weeks after pruning when new buds were just sprouting. Four successive drenching sprays were applied over a period of three weeks. The solutions tested were ammonium sulphate, ammonium chloride, potassium sulphate, potassium chloride, potassium nitrate, calcium nitrate, sodium chloride and sodium sulphate. All solutions were used at 5% strength (w/v). Ammonium sulphate and calcium nitrate were also tried out at 10% strength. "Teepol" was included at 0.5% in all solutions as a spreader. Soil applications of ammonium sulphate and calcium nitrate at levels equivalent to 100 and 200 lb N/acre were also included as additional treatments. Five bushes comprised an unreplicated treatment. Regular counts of buds (damaged and undamaged) were made. These observations along with visual ratings of recovery yield the following classification of effects :— Very heavy damage 5 % ammonium sulphate 5 % ammonium chloride 10% ammonium sulphate 5 % sodium chloride Slight damage 5% potassium sulphate 5% sodium sulphate 9 oz ammonium sulphate (to soil) 16 oz calcium nitrate (to soil) Moderate damage 5% potassium chloride 10% calcium nitrate No damage 5% potassium nitrate 5% calcium nitrate 8 oz calcium nitrate (to soil) 18 oz ammonium sul­ phate (to soil) Untreated control Unfortunately no phosphates were included in this experiment. It would appear that the ammonium ion is very damaging when sprayed on buds and frame. It is to be noted that the sprays of 5 % ammonium sulphate supplied an amount of the salt equivalent to less than 35 lb N/acre. The effects of this spray were very similar to symptoms associated with poor recovery from pruning, in several instances that have been brought to our notice. The 10 % solution of this salt causes much heavier damage. H. B. Wijetunga & S. Wimaladharma PH 31 — Bud-growth in relation to diameter of pruned branch — (1969) Immediately after pruning of an area of TRI 2024, a large number of branches were marked and grouped into five size classes based on the diameter of the stem immediately below the pruning cut. Buds sprouting on each of ANNUAL REPORT FOR 1969 67 the selected branches, to a marked distance of 15 cm behind the pruning cut, were observed. At 19 weeks from pruning, observation indicated a clear relationship between size of branch and the number and.distribution of buds. Expressed as buds per unit length of stem, the larger branches appeared to be more productive. This trend is reversed when the results are converted to buds per unit area of bark. The smaller branches produce buds further back from the pruning cut and hence show more "dieback". It was also noted that a large proportion of buds initiating growth subsequently die off. Bud initia­ tion is earlier on the smaller branches. At the time of tipping, observations were made on the number of shoots tipped, off each size category of marked branches. As expected, more tippable shoots arose from the larger branches. However, as a result of the delayed budbreak on the larger branches, weight per shoot tipped tends to decline in the largest size class. H. B. Wijetunga & S. Wimaladharma PH 32 — Bud-growth on different clones — (1969) The clonal proving trial planted in 1963 (VP 3—St Coombs) was pruned for the first time in May. Five bushes with uniform sized frames were selected for observations from each of the twelve clones in this trial. Periodic counts were made of the total numbers of buds initiated and the numbers that die. It was observed that very substantial numbers (over 50%) of the buds initiating growth abort during the first 2 | months from pruning. The factors responsible for this deserve study. There is no obvious relationship between the yield of these clones and the counts of persisting or dying buds. Observations were continued until tip­ ping—at five months from pruning. Tipped shoot numbers too did not bear a direct relationship to yields of the clones. H. R. Solomon Fertilizers on mature tea PH 33 — Fertilizer allocation within the pruning cycle — (1969) This experiment has been commenced on old seedling tea at St Coombs. It sets out to determine the effects of differential allocation of a fixed cycle total of fertilizer nitrogen, between the different years of a four year cycle. The distribution of doses also allows for some information on the effects of the timing of the immediate pre-and post- pruning applications. The design comprises nine types of allocations at each of two levels of nitrogen and is replicated three times. Each of the 54 plots carries approxi­ mately 200 bushes. All plots are to receive potash and phosphate uniformly as a single annual dose of 60 and 20 lb/acre respectively. The nitrogen is to be applied as sulphate of ammonia in two doses each year at the appropriate levels. The two levels of nitrogen are 360 and 480 lb/4 year cycle. The tea was pruned towards the end of the year and appropriate plots have received their first nitrogen application. Plucking has commenced recently. H. B. Wijetunga & S. Wimaladharma 68 ANNUAL REPORT FOR 1969 Nursery trials Several trials have been recently started at St Coombs, Hantane and Passara sub-stations, to examine certain aspects of nursery practice. These include experiments on type, frequency and dose of nursery fertilizer, nursery watering and drought effects and the use of polythene tents in the early stages of establishment of cuttings. Details of these experiments are reserved for description at a later date. S. Wimaladharma, H. B. Ratnayake & A. M. Abeysinghe Miscellaneous PH 34 — Vegetative propagation of Hakea saligna — (1969) A preliminary experiment was carried out to determine whether the shel­ ter-belt plant Hakea saligna could be propagated vegetatively. Eight-inch long terminal sprigs and hardwood cuttings of the same length were employed. Three types of commercial "rooting powders" (Stimurhiz A, Stimurhiz AA and Seradix B) were tested for efficacy, along with untreated controls. Thirty cuttings were used for each treatment The basal ends of the cuttings were slightly moistened, dipped in the rooting powder and planted in normal nursery soil in polythene bags in the same manner as tea cuttings. The cuttings were placed under a standard low shade of coir matting. At six months 22% of the sprigs and 36% of the hardwood cuttings had produced satisfactory plants. Stimurhiz AA and to a lesser extent Stimurhiz A, have slightly promoted success. In view of the high cost of seed of this species, even this modest degree of success is encouraging. Further refinements of technique could probably improve percentage strike. H. R. Solomon PH 35 — Rooting of tea cuttings in liquid media — (1969) Preliminary experiments using aqueous solutions of a variety of com­ positions indicate that it may be possible to obtain rooting of tea cuttings in liquid media. If successful, such a system would have several advantages—in particular, economics of watering, more precise control of nutrient supply and ease of examining the progress of rooting. Early growth of the cuttings was most encouraging in several of the solu­ tions tested and it is proposed to continue this work. A particular attraction is that suitable systems of this type may remove obstacles encountered in the establishment of plants of clones that are "difficult rooters". VP 23 — The influence of node position on the development of tea cuttings—4 replicates of 10 treatments in randomized blocks—(1968) The purpose of this experiment was to study the number of suitable cuttings that can be taken for propagation from vigorous leader shoots obtained six months after pruning of clones TRI 777, DT 1 and TRI 2025. The results of this experiment showed that the effect of node position of cutting on shoot development was irregular in the early stages but differences disappeared as the plants grew older. Root development was unaffected by node position. ANNUAL REPORT FOR 1969 69 Cuttings from nodes 4 to 12 appeared suitable for practical purposes and plants produced from cuttings from the older nodes 9 to 12 compared favourably with those obtained from nodes 5 to 8 which are accepted as suitable in current practice. The clones behaved in a similar manner in respect of node position of cuttings and their development. S. Kulasegaram & D. Janakiram PLANT PROPAGATION Experiment VP 22 has been concluded. Clonal Testing Information on the clonal testing trials at the four locations, St Coombs (4,600 ft), Mid-Country Station (2,500 ft), Uva Station (3,400 ft) and Kottawa Sub-station (200 ft) is presented in a manner similar to last year. Additional information on these and other clonal testing trials may be obtained from the reports on the respective stations. Because of differences associated with climate, year of planting and man­ agement practices the experiments at the different locations cannot be made synchronous. This has necessitated the adoption of the following procedures in the presentation of results. (i) The results from all four trials planted in a particular year are tabulated together. It will be noted that in certain cases, the pruning cycle may differ between locations. (ii) When the tea has not yet completed its first cycle, ranking is based on the total yield obtained from the very first pluck to the last available record. (iii) In tea in its second or subsequent cycle, ranking is similarly based on total crop harvested to-date since the last prune. Where pruning of an experiment was done during the year and plucking in the new cycle has, therefore, not yet covered one year, the results are not presented. (iv) For purposes of comparison of mean yield obtained at the different locations, a calculated figure for yield as made tea per acre per annum is presented. This figure is the calculated yield for 12 months of plucking and is based on the total crop harvested during the actual number of months in which the tea has been in plucking. For example if a total yield of 3000 lb has been obtained during 30 months of plucking, the annual yield is 1200 lb made tea per acre. The actual number of months during which the tea has been in plucking is indicated in each column. 70 ANNUAL REPORT FOR 1969 (v) As in previous years, the ranked clones have been divided into three yield categories, namely above 2500, 1500-2500 and below 1500 lb made tea per acre per annum. While in the first cycle this figure is based on the actual period in plucking, in subsequent cycles the entire period extending from pruning to the last recorded pluck is taken into account in this yield computation. Likewise, the mean yield obtained for all clones together, is also based on this period. The period considered in each case is incorporated into the tables. It will be appreciated that the relative position of a given clone is a function both of its inherent yield potential and the adversities of environment to which it is subject. Accordingly, at St Coombs it would be expected that particular susceptibility to eelworm would suppress the performance of a clone. Simi­ larly, Shot-hole Borer and drought would be of importance at the Mid-Country and Uva Stations. The effects of all three of these adverse factors would progressively increase resulting in a steady decline of susceptible clones. That such factors are operative is evident from a consideration of relative rankings of clones at the different locations, and in the comparison of performance in a trial through successive years. Proneness to diseases like Phomdpsis and problems associated with recovery from pruning are probably additional contributory factors. Subject to the above comment, the ranking of clones in all experiments was generally similar to that of previous years. VP 1 — Clonal testing at St Coombs — (1961) MVP 1 — Clonal testing at the Mid-Country Station UVP 1 — Clonal testing at the Uva Station — (1961) LVP 1 — Clonal testing at the Kottawa Sub-station - VP 1 and MVP 1 have completed 40 and 36 months respectively in their second cycles. UVP 1 completed 45 months in the cycle in July when further plucking was suspended because of the drought and the experiment was pruned in October. LVP 1 has completed 20 months from pruning, in the third cycle. These trials are now on extended pruning cycles. The striking variation between locations in the period from pruning to commencement of plucking is indicative of the differential severity of treat­ ment and the weather conditions prevailing in the recovery period. Thus while plucking commenced 10 and 9 months after pruning in VP 1 and UVP 1 respectively, the relevant periods were 5 and 3 months for-MVP 1 and LVP 1. In accordance with the manner of calculation now adopted for purposes of yield categorization, it would follow that lesser numbers of clones qualify for inclusion in the higher categories in VP 1 and UVP 1. In UVP 1 it was noted that the majority of the clones in one of the four blocks (unshaded) defoliated during the drought but subsequently recovered. The ranking of clones in this trial is presented in Table 1. — (1961) - (1961) A N N U A L R E P O R T F O R 1969 71 TABLE 1 — Clonal testing trials (1961)—Experiments VP 1, MVP 1, UVP 1 and LVP 1—Ranking order of clones and yield categories—Bold type—over 2500 lb ; plain type—1500 to 2500 lb and italics—below 1500 lb made tea per acre per year, calculated yield during the period indicated SECOND CYCLE THIRD CYCLE VP 1 M V P 1 U V P 1 LVP 1 TRI 2025 TRI 2023 TRI 2023 TRI 2023 TRI 2023 TRI 2026 TRI 2025 TRI 2026 KEN 16/3 TRI 2025 TRI 2027 TRI 2027 MT/BG TRI 2151 T 5/3 TRI 2024 TK 48 N KEN 16/3 TRI 2151 TRI 2027 KEN 16/3 TRI 2026 TRI 2025 CY 9 DG 39 N KEN 16/3 CV5B1 MT/BG GMT 9 QT 1/5 N GMT 9 MT 18 MT/BG TRI 2024 MT18 NL 4/2 PA 22 DT 1 T 5/3 CY 9 GMT 9 TRI 2026 TRI 2027 DT 1 MT 18 K 150 T 5/35 MT/BG DG 39 SEED PA 22 DG 39 UH 9/3 GMT 9 TRI 2024 CV4B1 T 5/35 TRI 777 K 136 TRI 2151 SEED K 136 TK 48 TK 48 PO 26 MT 18 EN 31 UH 9/3 EN 31 UH 9/3 CY 9 QT 1/5 NL 3/1 PA 22 NL 3/1 CV5B1 K 150 DG 39 NL 4/2 EN 31 T 5/3 PO 26 QT 1/5 K 150 K 136 KEN 15/7 TRI 777 TRI 2024 TK 48 T 5/3 CK5 JBI PO 26 DT 1 NL 3/1 PO 26 PA 22 NL 4/2 QT 1/5 K 150 T 5/35 TRI 777 CR 4 KEN 15/7 K 136 N T5/35 SEED TRI 777 KEN 15/7 TRI 2151 DT 1 NL 3/1 CV5B1 EN 31 CVABX CR 4 CY 9 CV4B1 CR 4 KEN 15/7 CR 4 NL 4/2 Off 9/3 SEED CV4B1 40 36 45 20 No. of months from prune 9/66—12/69 10/66—10/69 10/65—7/69 4/68—12/69 Calculated mean yield (lb/acre) 6325 5517 6193 5124 for the period indicated ±364 +315 ±176 +314 No. of months in plucking 30 31 36 17 Yield (lb/acre) for 12 months plucking 2530 2136 2064 3617 72 ANNUAL REPORT FOR 1969 VP 2 — Clonal testing at St Coombs — (1962) MVP 2 — Clonal testing at the Mid-Country Station — (1962) UVP 2 — Clonal testing at the Uva Station — (1962) LVP 2 — Clonal testing at the Kottawa Sub-station — (1962) LVP 2 was pruned in April at the conclusion of an extended second cycle of 36 months. Plucking in the third cycle commenced at the end of July. The other three trials are in various stages of their second cycles. The data in Table 2 refer to the second cycles. Attention is again drawn to the variable periods between pruning and the commencement of plucking in the new cycle. TABLE 2 — Clonal testing trials (1962)—Experiments VP 2, MVP 2, UVP 2 and LVP 2r-Ranking order of clones and yield categories—Bold type—over 2500 lb ; plain type—1500 to 2500 lb and italics—below 1500 lb made tea per acre per year, calculated yield during the period indicated SECOND CYCLE VP 2 NAY 3 TRI 2016 D MG CH 13 TRI 2024 TRI 2039 TRI 2022 TRI 2020 TRI 2043 #13 /4 MG3B1 KP 204 MPA\ H6A\ NK4B29 No. of months from prune 20 5/68—1/70 Calculated mean yield Ob/acre) 1305 for the period indicated +109 No. of months in plucking 12 MVP 2 UVP 2 LVP 2 KP 204 KP 204 TRI 2022 CH 13 TRI 2039 TRI 2024 TRI 2016 MG KP 204 NK4B29 TRI 2024 MPA1 MPA1 TRI 2016 TRI 2043 TRI 2022 TRI 2022 NK4B29 TRI 2043 HI 3/4 TRI 2039 TRI 2024 NK4B29 MG NAY 3 CH 13 TRI 2016 MG3B1 TRI 2043 NAY 3 TRI 2039 MG3B1 CH 13 MG MPA1 MG3B1 D NAY 3 H13/4 TRI 2020 D TRI 2020 07/5/8 TRI 2020 D H6A\ H6A\ #6,41 28 38 36 7/67—11/69 10/66—12/69 4/66—4/69 2739 5252 10873 ±209 + 210 ±992 24 31 32 Yield (lb/acre) for 12 months plucking 1305 1370 2033 4077 ANNUAL REPORT FOR 1969 73 SECOND CYCLE MVP 3 UVP 3 LVP 3 DG 7 TRI 2021 B275 TRI 2024 TRI 2045 TRI 2021 TRI 202A DG 3 £7/27 TRI 2046 W 3 TGK 2 W/2-145 TRI 2045 DG ML 7 TRI 2021 W/2-145 TGK 2 DG 7 DG 3 TRI 2046 ML 7 TRI 2045 E7/27 W 3 DG 43 DG DG 3 TRI 2024 DG 7 B275 E7/27 W/2-145 DG 43 DG TRI 2046 TGK 2 ML 7 W 3 No. of months from prune 12 10/68—10/69 26 10/67—12/69 32 4/67—12/69 Calculated mean yield 0b/acre) for the period indicated 1075 ±105 4029 ± 7 5 10025 ±713 No. of months in plucking 8 20 29 Yield 0b/acre) for 12 months plucking _ 2417 4148 VP 4 — Clonal testing at St Coombs — (1964) MVP 4 — Clonal testing at the Mid-Country Station — (1964) UVP 4 — Clonal testing at the Uva Station — (1964) LVP 4 — Clonal testing at the Kottawa Sub-station — (1964) VP 4 was pruned in October at the conclusion of its first cycle. Yield was recorded only up to July. MVP 4 also completed the first cycle in October with yield being recorded up to the end of the cycle. UVP 4 which was pruned in November 1968 was in plucking only from August in the second cycle. Yield in the second cycle is, therefore, not considered yet. LVP 4 has com­ pleted 20 months in its second cycle. VP 3 — Clonal testing at St Coombs — (1963) MVP 3 — Clonal testing at the Mid-Country Station — (1963) UVP 3 — Clonal testing at the Uva Station — (1963) LVP 3 — Clonal testing at the Kottawa Sub-station — (1963) VP 3 was pruned in May 1969 at the end of the first cycle and plucking commenced at the end of the year. The other three experiments are in then- second cycles. Table 3 presents the ranking order of clones. TABLE 3 — Clonal testing trials (1963)—Experiments MVP 3, UVP 3 and LVP 3~Ranking order of clones and yield categories—Bold type—over 2500 lb ; plain type— 1500 to 2500 lb and italics—below 1500 lb made tea per acre per year, calculated yield during the period indicated 74 ANNUAL REPORT FOR 1969 The ranking order of clones is given in Table 4. TABLE 4 — Clonal testing trials (1964)—Experiments VP 4, MVP 4 and LVP 4—Ranking order of clones and yield categories—Bold type—over 2500 lb ; plain type— 1500 to 2500 lb and italics—below 1500 lb made tea per acre per year calculated yield during the period indicated FIRST CYCLE SECOND CYCLE VP 4 MVP 4 LVP 4 DW 12 PCG 2 TRI 2024 MO 241 SEED (LD) Hl/58 QT4/4 TRI 2024 CW 21 MO 146 #1 /58 SEED (LD) TRI 1114 MO 116 TRI 1526 MO 208 DW 12 CAR 7/10 TRI 2142 g r 4 / 4 PLLG 2 MO 116 TRI 1114 QT4/4 PLLG 2 PLLG 2 TRI 1114 TRI 1530 SEED (ILL) DW 12 MO 114 MO 208 TRI 1530 TRI 1526 MO 241 SEED (ILL) SEED (LD) CAR 7/10 MO 116 CAR 7/10 TRI 1530 MO 208 TRI 2024 MO 146 "R6 144 SEED (ILL) MO 114 MO 114 — — 20 — — (4/68—12/69) 5305 2714 4919 ±1102 + 298 ±1140 38 36 16 6/66—7/69 10/66—10/69 1675 905 3689 No. of months from prune Calculated mean yield Oh/acre) for the period indicated No. of months in plucking Yield 0b/acre) for 12 months plucking VP 5 — Clonal testing at St Coombs — (1965) MVP S — Clonal testing at the Mid-Country Station — (1965) LVP 5 — Clonal testing at the Kottawa Sub-station — (1965) VP 5 appears to have been planted on unsatisfactory soil and has thus generally fared poorly. LVP 5 was pruned in April at the conclusion of its first cycle and has commenced plucking in the second cycle. The ranking order of clones in VP 5 and MVP 5 is presented in Table 5. TABLE 5 — Clonal testing trials (1965)—Experiments VP 5 and MVP 5—Ranking order of clones and yield categories—Plain type—1500 to 2500 lb and italics— below 1500 lb made tea per acre per year, calculated yield during the period indicated FIRST CYCLE No. of months from prune Calculated mean yield 0b/acre) for the period indicated No. of months in plucking Yield 0b/acre) for 12 months plucking VP 5 MVP 5 DK 1 TRI 2024 fcS LD 999 DK 8 DA 1408 TRI 2024 DK 17 DA 1408 CC 34 K 145 DK 17 DT 95 g r s / 3 TRI 2045 2314 1038 ±257 + 84 24 20 7/67—7/69 1157 11/67—7/69 623 ANNUAL REPORT FOR 1969 75 Yield pb/acre) for 12 months plucking 11/68—9/69 LVP 10 — Clonal testing at the Kottawa Sub-Station — (1965) This trial also planted in 1965 at Kottawa Sub-station and including some of the 62-series was pruned in April. At the end of the first cycle, the clones ranked themselves as follows :— TRI 2023, T 62/5, 62/9, 62/1 and 62/7. The 62-series clones have shown promise and their yields averaged about two-thirds that of TRI 2023. VP 17 — Clonal testing at St Coombs — (1966) One and a half years of plucking were completed by the end of the year. The clones reported as outstanding in last year's report maintained their posi­ tions. The ranking order of clones is in Table 6. TABLE 6 — Clonal Testing Trial at St Coombs (1966)—Experiment VP—17—Ranking order of clones and yield categories—Plain type—1500 to 2500 lb and italics—below 1500 lb made tea per acre per year, calculated yield during the period indicated FIRST CYCLE VP 17 SM 404 T62/9 YF6/1 PK 2 TRI 2024 PL 1 GF5I01 T62/8 LD 999 No. of months from prune — Calculated mean yield for the period 2007 indicated ±312 No. of months in plucking 18 4/68—10/69 Yield (lb/acre) for 12 months plucking 1338 MVP 6 — Clonal testing at the Mid-Country Station — (1966) The ranking order for the first ten months of plucking is presented in Table 7. TABLE 7 — Clonal testing trial at the Mid-Country Station (1966)—Experiment MVP 6—Ranking order of clones and yield categories—All clones gave below 1500 lb made tea per acre per year, calculated yield during the period indicated FIRST CYCLE MVP 6 TRI 2023 PG2/1 1SB TRI 2024 DG 43 No. of months from prune — Calculated mean yield (lb/acre) for 707 the period indicated ± 95 No. of months in plucking 10 76 ANNUAL REPORT FOR 1969 VP 21 — Clonal testing at St Coombs — (1967) These plots have completed less than one year of plucking. Being clones especially selected for outstanding quality characteristics, yields are generally low. TRI 1526, TRI 2142, KEN 16/3, TRI 1114 and DT 1 are the better yielders. MVP 7 — Clonal testing at the Mid-Country Station — (1967) No records are yet available. LVP 11 — Clonal testing at the Kottawa Sub-station — (1967) This trial includes the clones TRI 2023, T 62/3, 62/5, 62/6, 62/7 and 62/9. Plucking commenced in June. ' H. R. Solomon, H. B. Ratnayake, A. M. Abeysinghe & K. H. G. Gunapla PLANT BREEDING VP 10 and VP 11 — Selections from open and hand pollinated seedlings— (1962; 1963) The clonal progeny of the selected bushes continued to be under observa­ tion. A total of 61 new clones which appeared vigorous in the observation rows were test manufactured in July-September for a preliminary assessment of their quality characteristics. Fifteen of these clones compare favourably with the standard clone DT 1 as regards quality. The final choice of clones for field test will be made after a second quality assessment in early 1970. A point of interest about these quality clones is that all except two had either clone TRI 777 or DT 1 as a parent. VP 12 — Selections from bi-clonal progeny — (1964) The original objective of this experiment was to compare the performance of clonal seedlings against the parental clones, namely TRI 2023, TRI 2024 and TRI 2026. Numerous vacancies occurred in a number of seedling plots and therefore comparisons of yield between the different treatments became mean­ ingless. The experiment was pruned in May and vegetative clones were selected from the seedling progeny. Recovery from pruning and subsequent growth were used as criteria for selection. Thirty such selections are undergoing nursery trials. VP 13 — Seedling progeny from eight commercial seed gardens — (1965) These bushes were pruned in May and selections were made using the rate of recovery from pruning and the vigour of growth of the new shoots as criteria. These selections have been reserved for nursery tests in 1970. VP 14 — Hand-pollinated seedlings — (1965) Twenty plants per clone of 32 new selections were planted out in rows in No. 7 Field. The clones continued to be under observation in 1969. VP 15 — Field selections from No. 11 and No. 14 Fields, St Coombs—{1964) These bushes were rested in May to obtain cuttings for preliminary nursery tests. Selection for field trials would be based on the available data on single bush yields and their performance in the nursery. ANNUAL REPORT FOR 1969 77 Cytogenetic studies a) Chromosome number Cytological examination of 35 approved clones has confirmed the previous reports that the diploid chromosome complement of tea is 30. It is proposed to survey a large number of clones for their chromosome numbers in the hope of discovering plants with aberrant numbers. b) Polyploidy There have been reports of spontaneous polyploidy in tea and it is commonly associated with an increase in the size of both vegetative and reproductive organs. Therefore induced polyploids are an additional source of genetic variation which may improve the over-all performance of existing clones or enhance a particular character while retaining most of the characteristics of the diploid progenitor. Clones DT 95, TRI 2023, TRI 2024, TRI 2025 and TRI 2026, were treated with different concentrations of colchicine. The initial indications are favoura­ ble but the foliage characteristics indicated that the affected part is only secto­ rial. It has not yet been possible to isolate a completely polyploid plant from the affected areas. Investigations into the methods of isolating polyploids after colchicine treatment are in progress. c) Mutations It is known that radiation induced gene mutations in plants are mostly recessive. It would therefore be difficult to recognize experimentally induced recessive mutations in a seedling population of tea. Previous results with gamma irradiation of tea seeds, ranging from 25-50 kilorads indicated that dosages above 25 kilorads were lethal. The survival of tea seeds was variable when the dosages ranged from 2.5—10 kilorads. Clonal cuttings were found to be more tolerant to these same dosages. A few of the surviving plants of clones TRI 2025 and HI3/4 after irradiation showed signs of damage such as mottling and crinkling of the leaves. All the surviving plants have been planted out in the field for further observation. A. R. Sebastiampillai & D. Janakiram Extension Experiments The management of these experiments on shade vs fertilizer passed into the hands of the newly constituted Division of Agronomy. Attention is directed to the report of that Division for an account of the progress of these trials. Acknowledgements The co-operation of the staff of the Plant Physiology Division both at St Coombs and the other stations and other officers who helped in the manage­ ment of experiments is gratefully acknowledged. Assistance received from the members of the Statistics Division in the design of experiments and in the analysis of data and the members of the Agricultural Chemistry Division for assistance and advice in the analysis of plant samples is recorded with thanks. 78 ANNUAL REPORT FOR 1969 Visits, Lectures and Symposia Visits The Plant Physiologist was a member of the TRI Delegation to the Twenty Fourth Tocklai Conference at Jorhat, Assam, N. E. India from 11th — 13th November. Lectures PETHIYAGODA, U . — "Axillary branching in the potato". Paper presented at the 25th Annual Sessions of the Ceylon Association for the Ad­ vancement of Science at Colombo in December. Publications HUMPHRIES, E; C. & PETHIYAGODA, U. (1969). Effect of Morphactin on growth of potatoes. Dtsh. Bot. Ges. Neue Folge 3, 139-147. KULASEGARAM, S. (1969). Studies on the dormancy of tea shoots. 1 — Hor­ monal stimulation of the growth of dormant buds. Tea Q. 40,31-46. KULASEGARAM, S. (1969). Studies on the dormancy of tea shoots. 2—Roots as the source of stimulus associated with the growth of dormant buds. Tea Q. 40, 84-92. PETHIYAGODA, U., KRISHNAPILLAI, S. & NAGARAJAH, S. (1969). Studies on the mineral nutrition of tea. 1—Techniques for growing tea plants- in sand culture. Tea Q. 40, 145-152. SEBASTIAMPILLAI, A. R. (1969). The production and cytology of polyploid strawberries, PhD Thesis, University of Reading, 189 pp. References GADD, C. H. (1928). Tea and soil acidity. Water culture experiments I & II. Tea Q. 1, 2-6 and 31-35. KULASEGARAM, S. (1969). Studies on the dormancy of tea shoots. 2—Roots as the source of stimulus associated with the growth of dormant buds. Tea Q. 40, 84-92. KULASEGARAM, S. (1969). Report of the Plant Physiology Division for 1968. Rep. Tea Res. Inst. Ceylon (2), 39-57. PETHIYAGODA, U. (1966). The importance of timing of pruning in relation to recovery. Tea Q. 37, 80-85. REPORT OF THE PLANT PATHOLOGY DIVISION Plant Pathologist — N. Shanmuganathan, BSc, PhD General Dr R. L. de Silva, Research Officer, left Ceylon on 14th September for post-doctorate research at the University of California, USA. He was awarded a Research Fellowship by the Federal Government of the United States of America. Mr P. V. Arulpragasam, Technical Assistant, returned in October from overseas training at Wye College, Ashford, UK, where he obtained his MPhil. Mr S. M. M. R. Gnanadarshana, Laboratory Attendant, who assumed duties in April resigned in June and was replaced by Mr K. R. J. Dickson in September. Dr N. Shanmuganathan functioned as a joint editor of the Institute's publications from 1st September. He was also in charge of the administration of the Institute's library and studio from that date. Laboratory Investigations Fungicides for phomopsis theae To-date 19 compounds have been examined in the laboratory for fungicidal activity against spore germination and mycelial growth of P. theae, and for persistence on the stem when applied on tea plants in the field. The d i v i s i b i l i t y of the 19 fungicides was also determined in the laboratory. The results are summarized below. a) Activity against spore germination Of the 19 compounds tested, 12 showed high activity, the ED 50 values ranging from 0.5 to 8 ppm, while the activity of the remaining seven was poor (see Table 1). b) Activity against mycelial growth Only five of the 19 compounds tested showed high activity (ED 50 values ranging from 0.5 to 4 ppm), while ten showed no significant activity even at 80 ppm (see Table 1). TABLE 1 — Comparison of the fungitoxicity of nineteen fungicides against Phomopsis theae Minimum inhibitory concentration (ppm) Fungicide Activity against Activity against spore germination mycelial growth Daconil 0.5 > 8 0 Difolatan 0.5 4 Urbacid 0.5 40 Antimucin 1 10 Actidone 1 4 Cufram Z 1 > 8 0 Verdasan 2 4 Dodine 2 > 8 0 Aureofungin 2 > 8 0 Tuzet 4 40 Anthracol 4 40 Brestan 8 40 Tiezene 20 > 8 0 Benlate 20 0 .5 Santar 40 > 8 0 Perenox > 8 0 > 8 0 Nickel chloride > 8 0 > 8 0 Vitavax > 8 0 > 8 0 Bayer 6059 > 8 0 > 8 0 79 80 ANNUAL REPORT FOR 1969 c) Persistence in the field The persistence of 10 of the above 19 compounds was tested in the field in two experiments. The fungicides were applied to the stem of young tea plants at a concentration of 0.5 % and persistence was determined by a bioassay technique using P. theae as test organism. The 10 compounds tested were Verdasan, Difolatan, Bayer 6059, Aureo- fungin, Actidione, Tuzet, Antimucin, Daconil, Brestan and Benlate. Two fungicides which showed very good persistence were Antimucin and Verdasan, the former being superior to the latter. Both these compounds were present in detectable quantities, 53 days after spraying in one experiment. All the other compounds showed poor persistence, except Benlate and Difo­ latan which exhibited moderately good persistence. d) Diffusibility The diffusibility of the 19 compounds was tested in the laboratory by applying standard amounts of the fungicides to filter paper discs placed on seeded (P. theae) agar plates. The mean diameter of the inhibition zones produced by each fungicide was taken as the measure of its diffusibility. Fungicides that showed very high diffusibility were Antimucin, Benlate and Verdasan. Bayer 6059, Difolatan, Tuzet, Urbacid, Dodine, Actidione, Daconil, Santar, Brestan, Aureofungin and nickel chloride showed moderate to good diffusibility, but Cufram Z, Perenox, Tiezene, Vitavax and Anthracol exhibited little or no diffusibility at the concentrations tested. Fungicides for Monacrosporium ambrosium The fungicidal activity of five compounds—prospective candidates for systemic control—against spore germination and mycelial growth of M. ambrosium, the fungus associated with the Shot-hole Borer, was studied in the laboratory in agar culture. The compounds tested were Actidione, Venturi- cidin, Benlate, Aureofungin and Vitavax. Results showed that the compound most active against spore germination was Actidione, which caused complete inhibition of spore germination at 10 ppm. The other four compounds had no significant effect on spore germi­ nation even at 80 ppm. Benlate was the most active compound against mycelial growth, causing significant reduction in growth at 0.5 ppm and complete inhibition at 80 ppm. None of the other compounds caused complete inhibition even at 80 ppm (the highest concentration tested), although both Actidione and Aureofungin caused significant reduction in growth at this concentration. N. Shanmuganathan & R. N. Bopearatchy Fungicides for Exobasidium vexans Exobasidium vexans Three organic fungicides, viz Zineb, Tuzet and Vitavax, and Brestan (triphenyl tin acetate) were compared with Perenox (copper oxide) for effec­ tiveness against spore germination of E. vexans. The ED 50 values of these ANNUAL REPORT FOR 1969 81 compounds were estimated from the results of spore germination studies carried out on agar media containing varying concentrations of the fungicides. The results are shown below :— Fungicide ED 50 (ppm) Perenox 6.7 Zineb 2.7 Brestan 0.65 Vitavax 0.13 Tuzet 0.07 N. Shanmuganathan & T. V. Saravanapavan Greenhouse Investigations Experiments with Benlate (Du Pont Fungicide 1991) P83 — Uptake of Benlate by tea shoots and young tea plants — (1969) a) Uptake by tea shoots Four vigorously growing leader shoots taken from 2-year-old TRI 2023 plants were brought to the laboratory and allowed to stand in a solution (0.05%) of the fungicide. The movement of the fungicide in the shoot was followed by a bioassay technique using P. theae as test organism. There was positive evidence of the uptake of Benlate by the shoots. After 72 hr, detectable amounts of the fungicide were present in stem sections taken 4, 6, 10 and 14 in. from the cut-end of the shoots. There was no significant fungicidal activity in the leaves, but the first and second lateral shoots contained detectable quantities of the fungicide. b) Uptake by young plants When the roots of 1-year-old tea plants were immersed in a solution (0.05%) of Benlate, there was evidence of uptake of the fungicide. On the 8th day, fungicidal activity was detected in stem discs taken 4, 8, 11, 12 and 14 in. from the base of the plant. Some of the lower leaves also showed measureable fungicidal activity. c) Uptake by potted plants The uptake of Benlate by tea plants was also studied in the greenhouse using 18 months old, TRI 2025 plants growing in pots. Eight applications of a 0.05% solution of Benlate were given to each plant at the rate of 250 ml per application. The applications were made between 13th August and 22nd September. Detectable amounts of the fungicide were present in stem sect­ ions taken from various parts of the treated plants at frequent intervals after the last application of fungicide. On the last sampling date, ie 26th October, fungicidal activity could be detected in stem sections taken 6, 12 and 18 in. from the base of a treated plant. A leaf taken at a height of 18 in. from the base also showed significant fungicidal activity. P84 — Systemic activity of Benlate — (1969) An experiment was conducted in the greenhouse to investigate the syste­ mic action, if any, of Benlate. This fungicide is claimed to possess high systemic activity by the manufacturers. 82 ANNUAL REPORT FOR 1969 One-year-old, TRI 2025 plants growing in pots were used for this experiment. The following treatments were applied :— 1. Control 2. Four applications of the fungicide prior to inoculation 3. Four applications of the fungicide before inoculation and eight applications after inoculation, and 4. Eight applications of the fungicide after inoculation. The fungicide was applied to the soil as a 0.05% solution, 250 ml being applied per plant per application. The interval between applications varied between 2-7 days depending on weather conditions. There were 10 plants per treatment, and all plants were inoculated once on the collar using a culture of P. theae, after the pretreatment applications of the fungicide were concluded in Treatments 2 and 3. After inoculation, watering was kept to a minimum to induce the development of large lesions. Results were recorded two months after inoculation. Results showed that Treatment 3, which received 12 applications of Ben­ late had the smallest lesions, followed by Treatment 4, which received eight applications. Treatment 2, which received four applications all before inocu­ lation had lesions smaller than the control, but larger than treatments 3 and 4. The differences between treatments were, however, not significant statistically. The experiment will be repeated in 1970. N. Shanmuganathan & R. N. Bopearatchy P85 — Effect of3 levels of nitrogen and 3 levels ofpotash on Phomopsis cankers — (1969) The effect of three levels of nitrogen and three levels of potash on Pho­ mopsis cankers is being investigated in a pot experiment in the greenhouse. One-year-old plants of the highly susceptible clone KEN 16/3 were planted in pots and left unfertilized for about six months. The treatments were then applied, the required amounts of nitrogen and potash being given once every three months. There are 10 plants per treatment and all plants receive the same dose of phosphate. After six fertilizer applications, the plants will be inoculated with P. theae and the size of the resulting lesions will be used to estimate the effectiveness of the treatments. N. Shanmuganathan & R. N. Bopearatchy Field Experiments and Trials The following experiments have been concluded: Pl l , P23, P28, P29, P31, P52, P53, P57 to P59, P62 to P68, P70 to P75, P78 to P80 and P82. Reference is made to these experiments in the Report for 1968, and they are now deleted. 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. Results of this long-term experiment, which was concluded in 1969, are given below. ANNUAL REPORT FOR 1969 83 TABLE 2 — Viability and infectivity of tea root segments retrieved from the soil after burial for various periods Period of burial (years) Roots containing viable Poria (%) Infective root segments (%) 95.0 2 88.3 48.3 3 76.6 19.2 4 46.6 21.4 5 11.7 0 It will be noted that there is a progressive decline in the percentage of roots containing viable Poria with increasing time of burial. After five years' burial in fallow soil, only about 12% of the root segments contained viable Poria mycelium. Inoculations with these roots have so far not produced any positive results, indicating that these root segments do not possess suffi­ cient inoculum to infect tea plants. The depth of burial had no significant effect on survival of the fungus. P13 — Selection of bushes resistant to P. hypolateritia at Mattakelle Estate, Talawakele — (1964) The six clones, that were free of infection in the pot trial, were transferred to a bed in which large tea stumps infected with P. hypolateritia were buried. Observations during the year showed that all six clones were susceptible to the disease. Clone 9/16 grew very luxuriantly despite infection by P. hypola­ teritia and appeared to be tolerant to Poria. The experiment is concluded. P45 — Resistance of clones to P. hypolateritia — (1966) Details of this experiment were given in the Report for 1966. Results of the inoculations showed that all the 19 clones tested are susceptible to P. hypolateritia. The experiment is concluded. P55 — Studies on inoculum potential—Quantity of inoculum and age of host plants on the infection of tea by P. hypolateritia — (1967) Observations are continuing in this experiment. PS6 — Soil fumigation with methyl bromide on soil nitrogen, soil microflora and the growth of tea and Guatemala grass — (1967) Nitrogen estimations of soil samples taken from experimental plots showed that following fumigation there is a rapid build-up of ammonia-nitrogen, which reaches a peak about 10 weeks after fumigation. Thereafter, there is a gradual decline and the level drops to that of the untreated after 30 weeks. On the other hand, the build-up of nitrate-nitrogen is slower, the maximum concentration occurring 20 weeks after treatment. The decline in the level of nitrate-nitrogen is also gradual, but dropped sharply after the 30th week due to heavy rain and consequent leaching. These effects were best shown by the one-pound treatment and less so by the half-pound treatment; there was little difference between the quarter-pound dosage and the control. 84 ANNUAL REPORT FOR 1969 There was marked stimulation in the growth of tea planted on plots fumigated with the half-and one-pound dosages. The mean heights of the plants in each treatment six, eight, 10 and 12 months after planting are given below. Treatment (lb/100 sq. ft) 6 Mean height of plants (cm) 8 10 12 i 0 52.2 67.1 75.5 104.4 0.25 49.9 64.4 74.9 112.3 0.5 67.3 85.5 91.9 127.2 1.0 66.6 83.7 91.5 129.8 The increase in growth due to fumigation was over 20 % in the case of the half- and one-pound dosages. There were no significant differences in growth between the control and the quarter-pound dosage, and between the half- and one-pound dosages. Guatemala grass has so far not shown any clear response to fumigation with methyl bromide, but is growing well on treated plots without showing any adverse effects. No significant differences could be discerned between the treatments and the control in regard to microbial populations, and this aspect of the problem will be re-investigated. P69 — Resistance of clones to P. hypolateritia — (1967) Of the 19 clones tested in this experiment, only Clone UR 12 failed to become infected, when inoculated with infected root segments in pots. This clone will be tested further. The experiment is concluded. P76 — Studies on inoculum potential—Determination of the smallest effective inoculum for infection of young tea plants by P. hypolateritia — (1968) In this experiment the amount of inoculum is varied by using infected root segments of different lengths and diameters. Twelve different volumes of inocula were tested on potted plants of clone TRI 2024. The plants were approximately one year old at the time of inoculation. The smallest volume of inoculum tested was 0.8 ml and the largest 50.4 ml. Results recorded after 12 months showed that the smallest effective inoculum was 12 ml; this is much higher than the 6 ml previously determined (cf P46, Annual Report for 1967). The experiment is concluded. 1969 Experiments P86 — Control of P. hypolateritia by soil treatment with chloropicrin—4 repli­ cates of 5 treatments + control — (1969) In this experiment four different rates of chloropicrin, viz 1, 2, 4 and 8 ml/sq. ft (0.37, 0.74, 1.48 and 2.96 lb per 100 sq. ft respectively), were compared with the standard rate of methyl bromide (0.5 lb per 100 sq. ft) for effectiveness against P. hypolateritia. Chloropicrin was applied to the soil 6 in. below the surface using injector guns, and plots were sprinkled with water and covered with Guatemala grass mulch immediately after treatment. The efficacy of the treatments was assessed by burying infected root segments in the plots at depths of 1 and 2 ft prior to fumigation ; these were retrieved six weeks after treatment and their viability determined. Results showed that control ANNUAL REPORT FOR 1969 85 was 100%, when chloropicrin was applied at the rate of 8 ml per sq. ft. Con­ trol was over 80 % at 4 ml per sq. ft, but control with the lower rates was not satisfactory. Control with methyl bromide was 100%. P87 — Effect of soil treatment with five fumigants on the growth of young tea—5 replicates of 5 treatments + control — (1969) The five fumigants under test are chloropicrin, DD, Trapex, WN 12 and methyl bromide. The five compounds were applied separately to plots (200 sq. ft) at the rate of 1 lb per 100 sq. ft, and one month after treatment, 1-year-old plants of clone TRI 2024 were planted on the plots. The growth of these plants will be assessed at regular intervals during the next 12 months. N. Shanmuganathan & S. R. A. Fernando Blister Blight (Exobasidium vexans) P14 — Epidemiology of Blister Blight — (1962) No further work was done on epidemiology of Blister Blight during the year. About 100 plants each of two highly resistant and two highly susceptible bushes are being raised in the nursery to plant a small block in the field, with a view to obtaining material for future studies on the mechanism of resistance to Blister Blight. N. Shanmuganathan & T. V. Saravanapavan P26 — Loss of crop caused by Blister Blight on unshaded seedling tea — (1966) The experiment is continuing. It was decided in 1969 to extend the prun­ ing cycle to five years so that crop losses can be assessed over a five-year prun­ ing cycle. The experiment will, therefore, be continued until 1971. The tea was pruned in June and was brought into plucking in September, when yield recordings were resumed. R. L. de Silva & S. Murugiah P30 — Loss of crop caused by Blister Blight on unshaded VP tea (Clone TRI 2024) —(1966) The experiment is progressing. Results will be analysed when the experiment has completed one full pruning cycle. P60 — 2 levels of nitrogen, 4 levels of infection of Blisier Blight and 3 levels of shade on yield of two clones (TRI 2023 and 2025) — (1967) The tea in this experiment was brought into bearing during the year under review. Pre-treatment yield recordings will commence in 1971, after the tea has been in bearing for one full year. R. L. de Silva, T. V. Saravanapavan & S. Murugiah P61 — Protection of tea against Blister Blight by disease forecasting — (1967) This experiment ran into trouble during the middle of the year because of inability to predict infection accurately in certain instances. There is no provision in the forecasting device in its present form to accommodate 86 ANNUAL REPORT FOR 1969 "predicted infections" lower than 5 % and higher than 77.5 %. Consequently, the experiment was discontinued. It is intended to rectify this defect and test the device again when time permits. R. L. de Silva & T. V. Saravanapavan P77 — Fungicides for the control of Blister Blight on VP tea — (1968) In this experiment, two new fungicides, viz Benlate (Du Pont 1991) and Fycol (Copper oxychloride and nickel chloride) were tested for their efficacy in controlling Blister Blight. The two fungicides were compared with the performance of nickel chloride, nickel sulphate and a standard copper oxide formulation. All five fungicides were tested at the rate of 0.5 oz per acre; Fycol and Benlate were also tested at the rate of 1 oz per acre. Results showed that the best compounds were copper oxide and nickel sulphate. There was no significant difference between these two compounds in regard to blister blight control. There was also no significant difference between Benlate (both rates) and untreated control. Nickel chloride and Fycol (both rates) gave almost the same degree of control. R. L. de Silva, T. V. Saravanapavan & S. Murugiah 1969 Experiments P88 — Fungicides for the control of Blister Blight on seedling tea—3 replicates of 9 treatments + control — (1969) Vitavax and Tuzet, two new fungicides that showed good promise in the laboratory tests, were compared with a standard copper oxide formulation for blister blight control. The three compounds were each tested at three different rates, viz 1, 2 and 4 oz per acre. Results showed that Vitavax and Tuzet were equally effective, but both compounds gave significantly less control than the copper oxide formulation. N. Shanmuganathan, 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) Details regarding the layout of this experiment can be found in the Annual Report for 1965. The final assessment for canker incidence was carried out in April, before the experiment was concluded, when in addition to the number of deaths, the number of cankers on each plant was also recorded. A row of TRI 2024, selected at random, was also assessed similarly to determine its relative resis­ tance. The results are shown in Table 3. For estimating the relative resistance of the clones in this trial, clone TRI 2024 was selected as the standard. The figures given in Table 3 are the weighted means of the total number of cankers for each clone. In cases where no discrete cankers could be discerned on dead plants, a score of four was given per plant as previous experience has shown that deaths result only when multiple infections occur on the collar (unpublished data). ANNUAL REPORT FOR 1969 87 No. of cankers (weighted means) DK 1 777 K145 DT 1 NAY 13 3.22 3.32 4.45 4.55 4.55 NAY 28/8 NAY 3 GMT 9 2046 2025 4.70 5.64 6.06 6.11 6.24 2039 NAY 27 2016 2027 2022 6.82 7.50 8.20 8.59 9.00 2151 MTBG NL3/1 25 2024 9.10 9.25 13.23 13.81 15.31 UH 9/3 17.71 The figures in bold print are not significantly different from the corres­ ponding figure for 2024 (P < 0.05). None of the figures was significantly greater than that of 2024 The results confirm the general observation that clone TRI 2024 is highly susceptible to Collar and Branch Canker Disease in Uva. The most suscep­ tible clone in this trial was UH 9/3. Other clones that showed poor resistance were TRI 2016, 2027, 2151, MTBG and NL 3/1. UH8 — Resistance of clones to P. theae at Glen Devon Estate, Halgranoya— (1965) For details of this experiment, see Annual Report for 1965. The experi­ ment was concluded in April. The results, summarized in Table 4, give the weighted means of the total number of cankers observed in each clone. For estimating the relative resis­ tances of the different clones, again clone TRI 2024 has been used as the stan­ dard. TABLE 4 — Relative resistance of 20 tea clones to Pho­ mopsis theae using clone TRI 2024 as the stan­ dard No. of cankers (weighted means) 2023 2027 2021 2016 1526 DT 1 2.50 2.50 2.50 2.50 2.50 2.50 777 740 2022 K 145 GD 5/110 2026 2.70 2.70 3.00 3.22 3.22 3.22 DK 1 2142 GD 3/113 2046 2039 2151 3.32 3.58 3.66 4.24 4.34 4.64 D T 9 5 2024 KEN 16/3 5.04 6.33 6.96 The figures in bold print are not significantly different from the corres­ ponding figure for 2024 (P < 0.05). None of the figures was significantly greater than that for 2024 The results showed that 2024 was a highly susceptible clone, although the most susceptible clone in this trial was KEN 16/3. Clones 2023, 1526, 2016, 2021, 2025 and DT 1 proved to be highly resistant, whereas clones 2142, GD 3/113, 2046, 2039, 2151 and DT 95 appeared to be of low resistance. The other clones were somewhat intermediate in resistance. TABLE 3 — Relative resistance of 20 clones to Phomopsis theae using clone TRI 2024 as the standard 88 ANNUAL REPORT FOR 1969 P18 — Clonal resistance, pathogenicity of isolates of P. theae and effect of age of bushes on disease development — (1964) The last series of inoculations in this experiment, the details of which are given in the Annual Reports for 1965 and 1966, were carried out in February and the resulting cankers were measured in June. Full results are summarized in Tables 5, 6 and 7. The proportion of plants that became infected was approximately the same in 1966, 1967 and 1969, while in 1965 it was significantly less (Table 5). The biggest lesions were obtained from the 1967 and 1969 inoculations, and the smallest from the 1965 inoculations. TABLE 5 — Results of inoculations of 20 tea clones with Phomopsis theae Year of Plants Mean lesion inoculation infected (%) length (cm) 1965 64.3 1.41 1966 97.3 5.79 1967 99.6 3.72 1969 99.2 6.21 It will be noted that none of the 20 clones tested in this experiment was immune to infection (Table 6). In presenting these results, clone TRI 2023 has been selected as a standard for estimating the relative resistances of the clones. TABLE 6 — Mean lesion lengths (cm) on 20 tea clones after inoculation with Phomopsis theae Year of inoculation Clone 1965 1966 1967 1969 D T I 1.21 5.29 3.40 4.63 2025 1.63 5.82 4.00 3.35 2016 1.94 5.80 4.54 7.74 2027 1.43 6.49 3.42 5.42 2151 1.41 7.12 3.50 5.95 25 1.33 7.11 4.63 3.44 MTBG 1.25 7.95 3.12 6.11 2024 1.30 5.99 3.22 4.00 2022 1.45 6.28 4.06 5.75 W 3 1.30 3.38 4.35 10.40 2023 1.24 3.74 2.29 2.83 740 1.35 5.54 3.51 8.11 2142 1.32 5.86 3.33 7.47 2039 1.46 6.58 3.44 6.37 2026 1.59 6.01 3.08 3.46 777 1.39 4.95 3.50 7.93 H6 Al 1.29 5.82 5.13 5.24 NAY 3 1.36 6.68 3.65 7.30 E7/27 1.41 5.62 3.97 7.86 D T 9 5 1.54 3.52 4.35 10.33 Figures in bold print are significantly greater than the correspon­ ding figures for 2023 (P < 0 05). None of the figures was signi­ ficantly less than that for 2023 in any year All results were subjected to analyses of variance and in Table 6, mean lesion lengths significantly greater (P<0.05) than the corresponding figure for clone TRI 2023 are presented in bold print. ANNUAL REPORT FOR 1969 89 The most outstanding clone in the trial was TRI 2023, followed by TRI 2026 which was the next best. Other clones that showed comparatively good resistance in at least one of the three years, 1966, 1967 and 1969 were TRI 2025, 2024 and 25, MTBG, W 3 and DT 95. Variation in the pathogenicity of isolates The inoculation studies demonstrated that marked variation exists in the pathogenicity of different isolates of P. theae, although all the isolates tested were pathogenic (Table 7). The variation in pathogenicity was very highly significant (P<0.001) in 1966, 1967 and 1969 and highly significant in 1965 (P<0.01). TABLE 7 — Mean lengths (cm) of lesions resulting from inoculation with 20 isolates o/Phomopsis theae on 20 tea clones 1965 Isolate L T 2 LT1 LT 5 LT 3 LT10 1.34 1.34 1.37 1.49 1.50 LSD (P < 0.05) = 0.11 ; (P < 0.01) = 0.15 1966 Isolate LT20 LT 16 LT 15 LT 19 LT 18 4.67 5.08 5.41 6.83 6.87 LSD (P < 0.05) = 0.55 ; (P < 0.01) = 0.72 ; (P < 0.001) = 0.92 1967 Isolate LT25 LT 27 LT 24 LT 26 LT 20 2.18 2.31 2.62 2.99 8.52 LSD (P < 0.05) = 0.32 ; (P < 0.01) = 0.45 ; (P < 0.001) = 0.54 1969 Isolate LT34 LT 37 LT 38 LT 36 LT 30 4.04 5.85 6.18 6.34 8.42 LSD (P < 0.05) = 0 . 9 7 ; (P < 0.01) = 1 .29; (P < 0.001) = 1.68 The results also indicated that there was a very highly significant inter­ action (P < 0.001) between clones and isolates, implying that most of the clones reacted differently to the different isolates. For a detailed discussion of the results of Experiments UP7, UP8 and P18, see The Tea Quarterly 40, 164-174. 1969 Experiments P89 — "Cutting across vs free-growing"—Effect on incidence of Phomopsis cankers at Aislaby Estate, Bandarawela — (1969) Fifty pairs of plants were selected at random in a 3-year-old clearing of clone DG 3, and one plant of each pair was cut-across at 15 inches in June, after the onset of the drought. The unpruned plant in each pair was allowed to grow unchecked. In December, the incidence of Phomopsis cankers on the 100 plants was determined by recording the number of cankers on each plant. Results showed that the incidence of Phomopsis cankers was significantly higher on the unpruned plants as compared with the pruned plants (see below). No. of cankers per 50 plants Pruned 4 Unpruned 37 90 ANNUAL REPORT FOR 1969 P90 — "Cutting-across vs free-growing"—Effect on disease serverity at the Uva Station, Gonakelle — (1969) Twenty five pairs of plants were selected at random in a 3-year-old clearing of TRI 2024, and one plant of each pair was cut-across at 18 inches in June, after the onset of the dry season. The unpruned plant was plucked in the normal manner. A week after pruning, the 50 plants were inoculated on the collar with a culture of a virulent strain of P. theae. The length of the resulting lesions were recorded in September. It was observed that the lesions on the unpruned plants were significantly larger than those on the pruned plants (see below). Mean length (cm) of lesions on 25 plants Pruned Unpruned 0.48 3.99 P91 — Two methods of pruning compared with unpruned—Effect on disease incidence, St Coombs, Talawakele — (1969) The two methods of pruning studied were clean prune and rim lung prune. The three treatments (including unpruned, control) were applied to randomized plots consisting of 10 plants each and replicated ten-fold. Prun­ ing was done on 7th March and plants were inoculated as in Experiment P90 on 15th March. The resulting cankers were recorded on 21st June. Mean length (cm) of lesions per 50 plants Clean prune Rim lung prune Unpruned control 1.34 0.22 1.12 No. of lesions per 50 plants resulting from inoculation with Phomopsis theae Clean prune Rim lung prune Unpruned control 7 4 34 The best treatment in this experiment was rim lung prune, which had fewer cankers and also smaller lesions. Only a few cankers developed on the clean- pruned plants, but due to severe sun scorch of the frames, it was not possible to measure them accurately and this may account for the abnormally large lesions recorded on these plants. P92 — Five fungicides for the control of P. theae on clone KEN 16/3 at St Coombs, Talawakele—5 replicates of 5 treatments + control in rando­ mized blocks — (1969) The five fungicides tested in this experiment were Aureofungin, Benlate, Antimucin, Actidione and Verdasan. The rates of application were as follows: Aureofungin — 0.5 g per gallon water Benlate — 4 oz fungicide + 4 oz surfactant in 100 gallons water Antimucin — 1 fluid oz per gallon water Actidione — 0.5 g per gallon water Verdasan — 4.5 g per gallon water. I i ANNUAL REPORT FOR 1969 91 Aureofungin, Benlate and Actidione were applied once a fortnight and Antimucin and Verdasan once a month from February to April. The fun­ gicides were sprayed on the collar and frames of the plants, using one gallon per 50 plants. There were five plots per treatment consisting of 10 plants each. The effectiveness of the treatments was assessed by recording the num­ ber of cankers on each plant in July. Analysis of the results indicated that none of the treatments was effective in reducing canker incidence significantly. P93 — Control of P. theae by spraying with suspensions of an antagonistic bacterium—Clone KEN 16/3, St Coombs, Talawakele — (1969). Attempts to control the disease by spraying with suspensions of a bact­ erium, highly antagonistic to P. theae and isolated from the bark surface proved unsuccessful. P94 — Six fungicides for the control of P. theae on Clone DG 3 at Aislaby Estate, Bandarawela—4 replicates of 6 treatments + control in rando­ mized blocks — (1969) The following six fungicides were tested in this experiment: Benlate, Aureofungin, Actidione, Brestan, Bayer 6059 and Tuzet. The experiment is concluded but results have not been analysed. P95 — Three fungicides for the control of P. theae on Clone DG 39 at Aislaby Estate, Bandarawela—4 replicates of 6 treatments + control in rando­ mized blocks — (1969) The three fungicides tested in this experiment were Verdasan, Difolatan and Bayer 6059. The experiment is concluded but results have not been ana­ lysed. P96 — Six fungicides for the control of P. theae on clones MT 18 and NA Y3 at Glenanore Estate, Haputale—4 replicates of 6 treatments 4- control in randomized blocks — (1969) The following six fungicides are being tested in this experiment: Antimucin, Verdasan, Benlate, Daconil, Difolatan and Bayer 6059. Results are not yet available. P97 — Three fungicides for the control of P. theae on Clone TRI 2027 at Alnwick Division (Brookside Estate), Uda Pussellawa—4 replicates of 6 treat­ ments + control in randomized blocks — (1969) The fungicides being tested are Benlate, Antimucin and Daconil, each at two rates. The results are not available. N. Shanmuganathan & R. N. Bopearatchy P98 — Effect of 3 levels of shade on Phomopsis incidence on 3 clones, TRI 2023, KEN 16/3 and NL 3/1 — St Coombs — (1969) This experiment was planted out in September 1968 in three blocks; there are two blocks on No. 6 Field and one on No. 3 Field of St Coombs. One of the two blocks on No. 6 Field has no shade, while the other has heavy 92 ANNUAL REPORT FOR 1969 shade. The block on No. 3 Field has medium shade. Shade which consists entirely of dadap (Erythrina lithosperma) was planted in 1969. Once the shade is well established regular assessments for Phomopsis incidence will be carried out. Each block has 480 plants each of the three clones planted in eight separate plots of 60 plants each. Root Diseases and shade trees P32 — Killing Grevillea robusta trees by Phortox treatment and by ring-barking — (1966) Details of this experiment are given in the Report for 1966. The following observations were made in this experiment, which was concluded during the year under review. Treatment 1 — Only 11 of the treated trees were killed, the remaining 14 having survived the treatment. The mean concentration of carbohydrates present in the roots of four treated trees at complete leaf fall was 6.5%. 2 — The number of trees killed in this treatment was 10 out of 25. The mean concentration of carbohydrates of five treated trees at complete leaf fall was 3.2%. From the point of view of depletion of root reserves, this treatment was very effective, although only 40% of the treated trees died. 3 — All the 25 ring-barked trees died. At complete leaf fall the mean concentration of carbohydrates in the roots of 10 ring-barked trees was 4.8%. Results of inoculations of dead trees with Ustulina deusta proved incon­ clusive, probably due to an error in determining whether infection had taken place or not. In many instances, there was considerable ectotrophic growth of the fungus on the inoculated roots, but without actual penetration. In some of the earlier observations, such roots were erroneously recorded as having been infected and this vitiated the results of the entire experiment. 1969 Experiments P99 — Effects of different methods of killing Grevillea robusta trees on susceptibility to root disease—4 treatments including control; 10 trees per treatment — (1969) The treatments are as follows : 1 — Control—untreated 2 — Felled without any treatment 3 — Trees pollarded at a height of 10 ft 4 — Felled as in Treatment 2 and stumps sprayed immediately with a 10% solution of Phortox. All experimental trees were inoculated with Ustulina deusta soon after the treatments were applied. Results will be recorded at the end of one year. ANNUAL REPORT FOR 1969 93 P100 — Susceptibility of Grevillea robusta trees treated with Phortox to Ustu- lina deusta—2 treatments including control; 40 trees per treatment — (1969) In this experiment 30 fully grown G. robusta trees were felled about two feet above ground level and the stumps then sprayed with 10% solution of Phortox in diesoline. Another 30 trees were felled likewise, but not treated with Phortox—these trees serve as controls. The susceptibility of the two lots of trees to U. deusta is being determined by artificially inoculating the roots at bi-monthly intervals. The experiment is continuing. N. Shanmuganathan & T. V. Saravanapavan P20 — Incidence of root diseases in tea following removal of shade trees by various methods — (1965) Further observations on root disease incidence have revealed two more cases of U. deusta around stumps of G. robusta trees felled without prior ring- barking. No disease has been noticed near stumps of trees felled after ring- barking. R. L. de Silva & L. A. Seevaratnam Oilspot Disease P21 — Rate of spread of Oilspot disease at Pedro Estate, Nuwara Eliya— (1964) No assessments were made during the last two years; an assessment will be carried out in 1970 after the tea in the experimental area is pruned. R. L. de Silva & P. Y- Arulpragasam Phloem Necrosis Virus Disease P27 — Tolerance of clones to Phloem Necrosis Virus Disease at Pedro Group, Nuwara Eliya — (1966) The plants in this experiment were tipped and brought into plucking during the year. There was no evidence of Phloem Necrosis Disease on any of the 146 clones, but two clones (TRI 23 and 2039) were found to be suscep­ tible to Collar and Branch Canker (P. theae). Clone 23 appeared to be highly susceptible to the disease as 14 of the 25 plants in the experiment were found to be affected. R. L. de Silva Stem Cankers in low-grown clonal tea LP3 — Rate of spread of cankers at Millakande Estate, Bulathsinhala — (1964) No assessments were made during the year. R. L. de Silva Recent observations In September a severe outbreak of stem cankers was observed in a planta­ tion in the Kalutara District. The outbreak occurred in a 2-year-old clearing and a number of plants were killed. The symptoms resembled closely stem cankers caused by Macrophoma theicola. Two clones, namely TRI 2023 and 94 ANNUAL REPORT FOR 1969 2026, were affected, the damage on 2023 being much more severe than on 2026. Several isolations were made from diseased specimens and 10 fungi have been selected for inoculation studies in 1970. Four of the 10 isolates resemble Botryodiplodia theobromae in cultural characteristics. N. Shanmuganathan & J. V. Sabanayagam Miscellaneous P81 — Forking the soil on the growth of clone TRI 2142 planted in heavy soil— 14 paired plots — (1968) For details of this experiment, see Report for 1968. Seven of the 14 plots were forked again in February. Visual observations at the end of the year showed that there was noticeable improvement in growth in only two of the seven forked plots, compared with the untreated plots. R. L. de Silva & R. N. Bopearatchy Leaf Spot Disease of Crotalaria spp. The fungus responsible for the leaf spot disease of Crotalaria anagyroides has been identified as Pleiochaeta setosa (see Report for 1968). In inoculation tests in the greenhouse, P. setosa has attacked C. anagyroides, C. usramoensis, C. striata, C. clarkei and C. brownei. Of the five species, C. anagyroides is the most susceptible, while C. clarkei is highly resistant. In the greenhouse, typical symptoms developed 4-5 days after spraying with a suspension of the spores of P. setosa. The damage was very severe on young plants, complete death occurring in most instances. Spraying with a copper fungicide prior to inoculation reduced markedly disease severity. A survey of the literature shows that the disease is identical to the one described by Gadd in 1935 and attributed to the fungus Ceratophorum setosum. N. Shanmuganathan Cercosporella leaf spot disease of tea (Calonectria theae) Severe defoliation of young tea plants caused by Cercosporella leaf spot disease occurred in a few estates in the Dimbula District in May-June. This disease, it may be recalled, used to be serious on old tea in the up-country estates about 15-20 years ago, especially in fields which had a dense shade of Acacia decurrens. The disease first appears as small, discrete, brown to grey spots, which later coalesce to form large diffuse necrotic patches. Both young and old leaves are susceptible to attack, and often the entire leaf may become diseased. Diseased leaves are shed rapidly and affected plants can be com­ pletely defoliated. There is evidence of variation in clonal susceptibility. Two clones that are highly susceptible are TRI 2025 and 2026, while TRI 2024 appears resistant. In greenhouse studies, copper sprays controlled the disease effectively, but in nurseries results were not satisfactory. It was evident that once the disease has appeared in a nursery, it is difficult to prevent its spread, even by frequent spraying, if wet misty weather persists. Routine prophylactic sprays should therefore be carried out in nurseries to prevent outbreaks of this disease. N. Shanmuganathan ANNUAL REPORT FOR 1969 95 Acknowledgements The co-operation of Agency Houses, Managers and Superintendents 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 the many commercial firms that supplied free samples of fungi­ cides for experimentation. Visits, Lectures & Symposia Lecture SHANMUGANATHAN, N. — "Research on Collar and Branch Canker of young tea {Phomopsis theae)" to the Nuwara Eliya Planters' Association at Nuwara Eliya in January. Visit Dr N. Shanmuganathan was a member of the TRI delegation that atttended the Twenty Fourth Tocklai Conference held at Jorhat, Assam, in November. After the conference, he visited several tea estates in Assam, Dooars and Dar- jeeling. Dr R. L. de Silva visited research establishments in the United States of America and the United Kingdom. Publications ARULPRAGASAM, P. V. (1969). The effect of some foliar spraps on the response of plants to cucumber mosaic virus infection. MPhil Thesis, University of London, 195 pp. KERR, A. & DE SILVA, R. L. (1969). Epidemiology of tea Blister Blight. Tea Q. 40, 8-18. PERIES, O. S. & DE SILVA, R. L. (1969). Problems of crop disease control with chemicals. Q. J. Rubb. Res. Inst. Ceylon, 44, 44-48. SHANMUGANATHAN, N. (1969). Studies on the parasitism and control of tea root disease fungi in Ceylon. Tea Q. 40,19-25. SHANMUGANATHAN, N. (1969). Studies on Collar and Branch Canker of young tea (Phomopsis theae Petch). 3—Clonal resistance. Tea Q. 40,164-174 SHANMUGANATHAN, N. (1969). Chemical control of tea diseases. In a supplement on Agriculture and Industry. The Times of Ceylon of 29th November 1969, 32 pp. SHANMUGANATHAN, N. & FERNANDO, S. R. A. (1969). Laboratory and greenhouse evaluation of some soil fumigants for toxicity against five root pathogens of tea. Tea Q. 40, 99-110. 96 ANNUAL REPORT FOR 1969 Details of materials used in experiments Material Actidione Anthracol Antimucin Aureofungin Bayer 6059 Benlate Brestan 60 Chloropicrin Cufram Z Daconil D D Difolatan Dodine Fycol Methyl bromide Nickel chloride Nickel sulphate Perenox San tar Tiezene Trapex Tuzet Urbacid Venturicidin Verdasan Vitavax WN 12 Active ingredient Cycloheximide (Crystalline) Zinc-propylene- bisdithiocarbamate Phenyl mercury compound Aromatic heptaenes Experimental fungicide Benlate benomyl fungicide 1991 Triphenyl tin acetate Chloropicrin Dithiocarbamate complex of zine, manganese and copper Tetrachloroiso- phthalonitrile Dichloropropane, dichloropropene Sulfenimide Dodine Copper oxychloride\ Nickel chloride J Concentration (%) 85 -100 70 } Methyl bromide Chloropicrin Nickel chloride Nickel sulphate Cuprous oxide Yellow mercuric oxide Zinc ethylene bis-dithiocar- bamate Methyl isothiocyanate Methylarseno-bis- dimethyldithiocarbamate Venturicidin Phenyl mercuric acetate Oxathiin systemic fungicide Trapex (20%)+ D D (80%) 50 60 99 80 75 80 65 25 (Cu) 27 (Ni) 98 2 100 100 50 (Cu) 80 20 80 10 2.5 75 Manufacturer or Agent in Ceylon Calbiochem Bayer Sandoz Hindustan Antibio­ tics Bayer Du Pont Hoechst Nippon Kayaku Universal Crop Protection Diamond Alkali Shell Chevron Chemical Montecatini Edison Tata Fisons Velsicol International Nickel International Nickel Imperial Chemical Industries Sandoz Montecatini Edison Scherring Bayer Bayer Murphy Imperial Chemical Industries Uniroyal Chemical Shell REPORT OF THE NEMATOLOGY DIVISION Nematologist—P. Sivapalan, BSc, PhD General Messrs D. G. S. Jayatilleke and A. T. Ethirveerasingham were appointed Technical Assistants in April. As in the previous year, attempts to recruit a Research Assistant proved unsuccessful. Laboratory Investigations Methodology Earlier experiments indicated that when processing root samples for eelworm recovery, the recovery per unit weight of root was inversely proportio­ nal to the size of sample processed. This inverse relationship appears to have a chemical basis and seems most likely to be an anionic effect. Further investigations are proceeding to evaluate this. In order to standardize the sample size, various weights were tested and the 4 g sample appeared to give the best recovery, with the least coefficient of variation. Therefore, this weight is now used as the standard sample size. P. A. John Biochemical Investigations Quantitative and qualitative studies of amino acids within feeder roots of different tea clones showed no correlation with the degree of susceptibility or resistance. Quantitative analysis of total free amino acids within feeder root samples showed significant increase with increasing levels of nitrogen fertilizer application. At any one level of nitrogen, nematode-infected roots contained more free amino acids than uninfected roots. This increase in the total amino acid content of nematode-infected roots appears to be due to increases in cer­ tain specific amino acids. Further investigations are proceeding. V. Shivanandarajah Anatomical Investigations Detail anatomical examination of nematode-infected roots have shown that the average diameter of the body of the meadow eelworm, is approximately a third of the average diameter of a cortical cell of a nematode-susceptible feeder root. This size difference appears to favour free movement of nematode within the cortex. Such freedom of movement does not cause excessive mechanical injury that may otherwise trigger unfavourable biochemical responses. Detail anatomical investigations are proceeding with resistant and tolerant tea clones. D. G. S. Jayatilleke Field Experiments and Trials The following experiments have been completed and the results published in the Annual Report for 1968 : 97 98 ANNUAL REPORT FOR 1969 N8, N13, N17, N18 and N29. Nl — Resistance and tolerance of clones to Pratylenchus loosi—4 replicates of 24 clones completely randomized in compact blocks at 3 locations— (1962) Twenty two test clones and two standard clones, DT 95 and TRI 2024 (chosen for resistance and susceptibility respectively), were included in this experiment which was initiated in March. The results were assessed in October. The clones were grown in mixed, infested soil collected from 25 different loca­ tions. The results of the assessments are presented in Table 1. TABLE 1 — Resistance and tolerence of clones to P. loosi Clone Mean shoot Mean root Nemas/g root Tolerance weight (g) weight (g) l o g ( n + l ) index TRI 62/9 363.9 142.4 2.75 52.8 K145 263.4 106.9 3.16 34.2 NEM 9* 222.4 54.5 3.14 20.5 DG 7 219.8 75.0 3.07 24.4 NEM 6 215.4 71.6 3.03 23.6 DT 95 208.9 78.6 3.50 3*-3 NEM 8 193.3 55.3 3.18 17.4 NEM 3 164.5 94.6 3.34 28.3 NEM 1 154.1 71.5 3.05 21.9 NEM 4 147.9 73.5 3.11 23.8 TRI 2016 146.5 62.1 3.13 19.2 NEM 15 134.0 84.1 2.99 16.7 NEM 5 128.8 37.4 3.18 11.7 TRI 2026 128.5 44.2 3.06 14.1 NEM 7 109.3 36.3 2.91 13.0 NEM 14 105.8 42.1 3.16 13.4 NEM 13 97.7 56.6 2.75 21.4 H 1 0 A 87.2 28.8 3.07 9 .3 T C 9 87.1 40.0 3.42 11.6 TRI 2043 84.7 30.4 2.63 10.9 D 74.8 34.6 3.16 10.9 TRI 2023 70.9 37.9 3.28 11.2 TRI 2024 47.4 22.9 3.18 7.3 DG 39 47.3 19.8 2.59 7.0 LSD ( P --0 .05) 53.8 19.8 0.13 9.8 * Nematology selections from open pollinated progeny For evaluation of tolerance to eelworms, an index that combined both root weight and eelworm count was used in this experiment (Sivapalan 1969). Two clones, TRI 62/9 and K 145, were found to have a higher tolerance level than the standard resistant clone DT 95. These two clones are, therefore, rated as excellent tolerant eelworm clones. DG 7, NEM 3, NEM 4 and NEM 6 are rated as good eelworm tolerant clones. The remaining clones, are rated as eelworm susceptible. The 1969/70 eelworm tolerance test is now in progress. S. Samarajeewa & P. A. John N3 — Field performance of clones tolerant to P. loosi—(1964) The results of yield analysis and eelworm assessments are presented in Table 2 and 3 respectively. The yield of plots on St Coombs and Derryclare Estate are not presented as these were pruned in 1969. in their fourth year. As the plots at Chapelton Estate were earlier pruned in the third year, the first year yield of the 2nd cycle is presented along with the 4th year yield of the 1st cycle at Mooloya Estate (the plots at the latter location are due for pruning in the 5th year). ANNUAL REPORT FOR 1969 99 TABLE 2 — Field performance of clones tolerant to P. loosi at Chapelton and Mooloya Estates Mean yield (lb green leaf per /plot) Clone Chapelton Mooloya (1st year of 2nd cycle) (4th year of 1st cycle) M 241 74.8 60.8 M116 43.6 45.9 TRI 2142 63.0 62.6 TRI 2025 71.4 63.6 M208 57.3 45.0 D T I 51.1 56.4 LSD (/> = 0. 05) 12.3 1.5 (/> = 0. 01) 17.0 2.1 (P = 0.001) 23.5 2.9 Highly significant differences in yield were again evident between clones at Chapelton (Table 2). As observed in the first cycle, M 241 yielded best in the first year of the second cycle and it was followed closely by TRI 2025. The recovery of TRI 2142, which yielded better than TRI 2025 in the first cycle, was relatively slow. Clones M 116 and DT 1 yielded poorly. Significant differences in yield were also observed in the fourth year at Mooloya. In general, other than clone DT 1, the yields of all the test clones had dropped in the fourth year. The clones TRI 2025 continued to yield best, followed closely by TRI 2142. The clones M 116 and M 208 yielded poorly. TABLE 3 — Eelworm assessments (Mean counts* at Chapelton and Mooloya Estate) Chapelton Mooloya Clone Soil Root Soil Root (per lOOg) (per g) (per lOOg) (perg) M241 1.20 1.82 2.31 2.48 M116 1.69 2.04 2.21 2.35 TRI 2142 1.10 0.74 2.23 2.03 TRI 2025 1.39 1.97 2.28 2.47 M 2 0 8 1.12 1.99 1.76 1.60 D T I 1.12 1.45 1.92 2.17 LSD (P = 0.05) NS 0.91 NS NS * Transformed to log (n+1) The data on soil and root counts of populations of P. loosi are presented in Table 3. The nematode population (both in soil and roots) at Mooloya Estate had increased considerably in the fourth year, compared with the third year of pluck, while the population at Chapelton Estate remained unchanged. Assessments are to be continued into the second cycle. S. Samarajeewa & P. A. John N19 — Selective removal of old tea roots of varying sizes, followed by a period of rehabilitation under Guatemala grass (one year), on the subsequent growth of tea plants and eelworm build-up in roots at Ferham Estate, Lmdula—(\967) 100 ANNUAL REPORT FOR 1969 LSD (P = 0.05) 0.73 (P = 0.01) 1.02 S. Samarajeewa N 2 0 — Selective removal of old tea roots of varying sizes, followed by soil fumigation without a period of re-habilitation, on the subsequent growth of tea plants and eelworm build-up within roots at Kirimetiya Estate, Galaha—(1967) The results of assessments made at the end of two years are presented in Table 5. TABLE 5 — Eelworm assessments following selective root removal and soil fumigation (without rehabilita­ tion) Treatment* Mean shoot Mean root Mean eelworm count weight(g) weight(g) l o g ( n + l ) 1 101.7 45.1 0.95 2 105.2 38.5 1.23 3 81.3 36.3 1.02 4 95.4 43.1 0.48 5 151.9 54.9 0.66 6 40.9 19.9 1.68 LSD (J> = 0. 05) 43.4 13.8 NS (i> = 0. 01) 57.4 18.3 — • (J» = 0.001) 77.2 24.6 — *1. All possible roots removed and fumigated with D D at 60 gallons/acre 2. Only the large roots removed and fumigated with D D at 60 gallons/ acre 3. No removal of roots but fumigated with Ditrapex (WN-12) at 20 gallons/acre 4. All possible roots removed and fumigated with Ditrapex at 20 gallons/ acre 5. Only the larger roots removed and fumigated with Ditrapex at 20 gallons/acre 6. Untreated control. Due to a prolonged strike on the estate the experimental plots were not properly weeded or manured and the growth of the plants was, therefore', not entirely satisfactory. The results of assessments made at the end of the second year indicate that, in general, the growth of the plants in the fumigated plots, with or without root removal, was significantly better than in the untreated control. When resorting to complete fumigation (area fumigation), root removal does not appear to be critical. This experiment is terminated. The experimental plots were all planted to tea in August and growth assessments are to be made at the end of two years in August, 1970. The results of eelworm assessments made at the end of one year are presented in Table 4. TABLE 4 — Eelworm assessments following selective root removal Treatment Mean count per g root ( l o g ( n + l ) Complete root removal (up to pencil thickness) 0.00 Partial root removal (roots 1 in. thick and above) 1.06 N o root removal (control) 1.63 ANNUAL REPORT FOR 1969 101 S. Samarajeewa & T. Manivasagar N22 — Levels of N and K on nematode reproduction and pathogenicity is sand culture in pots — (1967) The results of assessments are presented in Table 6. At the higher levels of application of nitrogen (100 and 50 ppm), the growth of the nitrate (NOp treated plants was significantly better than the plants receiving the corresponding levels of N, in the form of ammonium (NH + ) . When nitrogen was supplied 4 in the form of nitrate, no significant growth difference was observed between different levels of N (100, 50 and 25 ppm.) On the other hand, when N was supplied in the form of ammonium, the growth was significantly better at 25 ppm, than at 50 or at 100 ppm. TABLE 6 — Assessments of sand culture treatments Mean weight (g) of shoot and root and nematode count Treatment Nematodes/g N O s N H 4 K Shoot Root root — 100 100 16.7 19.3 0 100 — 100 36.6 38.7 2.51 — 100 25 24.1 24.4 0.32 — 100 — 22.0 19.4 0.53 — 50 100 28.2 22.6 0.42 50 — 100 39.9 39.4 2.74 — 25 100 38.1 27.6 0 25 — 100 39.3 42.5 2.53 LSD (P = 0. 05) 8.5 8.3 0.57 CP = 0. 01) 11.4 11.2 0.76 (/> = 0.001) 14.9 14.7 0.99 As shown in the Table, hardly any nematodes were recovered from plants receiving N in the form of N H + , whereas moderately high levels of nematodes 4 were recovered from plants receiving N in the form of NO -. The relatively poor growth and the poor infection rate in plants receiving the NH 4 form could possibly be due to some form of toxicity, which seems to be increasing with increasing levels of NH+ application. The effects of different levels of K on nematode multiplication could not be determined as the levels of K were modified among treatments which received N in the form of (NH"^). The above observations may be peculiar to sand cultures and as the plants used in this experiment were relatively young (7 months old), the rate of 25 ppm of N may have been quite adequate. As N in the N H + form appears to be not suitable for the above type of 4 investigations, this experiment is to be repeated with all treatments receiving N in the form of NO". 3 T. Manivasagar 102 ANNUAL REPORT FOR 1969 N24 — Inoculum levels of Radopholus similis and pathogenicity to tea (TRI 2025) — (1967) Radopholus similis was found to multiply very readily in the roots of clone TRI 2025. However, along with R. similis, a certain number of P. loosi were also recovered from the roots of this clone. It is possible that the infected roots that were used as the source of inoculum of R. similis, may have also introduced a certain number of 1st stage larvae and eggs of P. loosi. In the circumstances, although pathogenicity was clearly evident, it was not possible to ascribe this to R. similis alone. Before repeating this experiment it is now proposed to establish a pure culture of R. similis on pepper plants, which is known to be a host of R. similis and not of P. loosi. This experiment is now terminated. S. Samarajeewa 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, Talawakele — 5 replicates of 3 treatments + control in rando­ mized blocks — (1968) The plots in which the old tea was treated with Shell Weed-killer T, at the rate of 2 gallons/acre and then planted to Guatemala grass, were subse­ quently fumigated with DD at 40 gallons/acre and then planted to tea (Treat­ ment 1). The plots in which the old tea was treated with Shell Weed-killer T, at the rate of 3 gallons/acre and then planted to Guatemala grass, were subse­ quently planted to tea, without any further treatments (Treatment 2). The plots in which the old tea was treated with Prefix (WP) at the rate of 3 lb/acre and where no visible symptoms of death of bushes were observed, were replanted to young tea without a period of rehabilitation or any other treatments (Treatment 3). The untreated plots were uprooted and fumigated with DD at the rate of 80 gallons/acre and then planted to tea, without any further treatments (Treatment 4). This experiment is continuing. S. Samarajeewa N26 — Arboricides on old tea due for uprooting, on the build-up of eelworm populations in replanted young tea at Galkande-watte Estate, Talawa­ kele—4 replicates of 3 treatments+control—in randomized blocks— (1968) The Guatemala grass was uprooted from all the plots and replanted to young clonal tea in November. The experiment is continuing. S. Samarajeewa N27 — Soil temperature on the build-up and pathogenicity of P. loosi in young clonal tea—3 treatments of 8 assessments eachj using 4 replicates at each assessment—(1968) The results of the assessments are presented in Table 7. ANNUAL REPORT FOR 1969 103 As shown in Table 7, 52.5° and 82.5°F appeared to be not favourable for the build-up of populations of P. loosi and at both temperatures, root popula­ tions began to drop towards the latter part of the experiment. Root growth was also found to be not satisfactory at the above temperatures. A significant increase in root population of P. loosi was observed in roots of plants grown at 60° and 70°F. These two temperatures, therefore, appear to be quite favourable for the build-up of P. loosi. At these two temperatures root growth was also found to be much better than at 52.5° or 82.5°F. These experiments will be repeated in special temperature tanks, where the soil temperature alone would be varied, to evaluate if the nematode popula­ tion changes are closely related to root growth rate (RGR) or, whether this is independent of RGR and related directly to temperature. T. Manivasagar N28 — Dose of methyl bromide requiredfor fumigating nursery soil—3 replicates of 4 treatments + control in randomized blocks—(1968) This experiment is concluded and the results published in The Tea Quar­ terly (Sivapalan 1969a). S. Samarajeewa N30 — Fertilizer types and levels on pathogenicity of P. loosi in tea—2 types of N, at 4 levels each+control—each applied to infested and unin- fested plants and each treatment replicated 4 times, in pots—(1968) On account of the high level of inoculation of P. loosi (10,000 nematodes per pot), the majority of the inoculated plants were severely stunted and died by about the fifth month of the experiment. This experiment was, therefore, discontinued. A new experiment was redesigned in 1969 (N43). S. Samarajeewa & P. A. John 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 other control—(1968) The first assessment carried out at the end of the first year indicated no infestation and no significant difference between treatments. This experi­ ment is continuing. S. Samarajeewa N32 — Sampling time on population levels of 3 species of parasitic nematodes in tea at 8 widely-spaced locations—{1968) The fortnightly assessments made during the first year indicated highly significant fluctuation in the population levels, at all test locations. These fluctuations appear to be closely correlated to moisture levels in the soil. In most of the locations the soil population levels appeared t o be inversely pro­ portional to the root population levels. This experiment is continuing and the data for the first year are being analysed. S. Samarajeewa, T. Manivasagar & D. G. S. Jayatilleke TABLE 7 — Effect of temperature on eelworm multiplication T E M P E R A T U R E 52.5°F 60.0°F 70.0°F 82.5°F Mean root Nemas/g Mean root Nemas/g Mean root Nemas/g Mean root Nemas/g Weeks weight(g) root* weight(g) root weight(g) root weight(g) root . 2 3 .2 1.86 3 .2 0.87 2.5 1.63 2.3 1.64 2 4 4.1 1.44 2.8 1.62 2 .9 1.45 3.1 1.98 £ 6 5.0 1.95 4.1 1.21 4 .7 1.45 2 .4 1.86 r 50 8 3 .7 2.09 4 .9 2.06 7.2 1.85 3 .7 1.12 ffl 10 3.8 0.38 3.7 2.22 9.1 1.48 3 .6 1.22 O 2 12 4 .7 0.67 5.5 2.29 8.4 1.86 2 .4 1.22 ^ 14 4 .4 1.02 4 .2 2.24 5.7 2.31 2.7 0.82 3 50 16 4.8 0.77 6.1 2.33 6.5 2.56 3.9 0.52 _ LSD © (P = 0.05) NS 0.98 1.9 0.73 2.6 0.35 NS NS (P = 0.01) 1.33 NS 0.99 3 .6 0.47 (P = 0.001) NS NS 4 .8 0.64 * Transformed to log (n+l ) ANNUAL REPORT FOR 1969 105 1969 Experiments N33 — Methyl bromide, Ditrapex (WN-12), Ditrapex followed by thatching, DD, DD followed by thatching, Fumazone followed by thatching and rehabilitation under Mana grass for one year on the rate of re-infestation of young replanted tea Derryclare Estate, Kotagala—3 replicates of 7 treatments+control in randomized blocks—(1969) The object of this experiment is to evaluate the efficacies of different soil fumigants, at lower rates of application, in controlling the meadow eelworm, as a routine pre-planting treatment. This experiment is also designed to evaluate the necessity for thatching fumigated areas. Periodical assessments will be made. S. Samarajeewa & T. Manivasagar N34— Terracur-P (5% granules) at one level, Nemacur-P (10% granules) at_ one level and Nemagon (20% granules) at 3 levels for control of meadow eelworm infestation, in young tea at Liyangahawela Estate, Bandara­ wela—3 replicates of 5 treatments+control in randomized blocks— (1969) The object of this experiment is to test the efficacy of granular systemic and non-systemic type nematicides in reducing nematode infestation of young tea clearings and to test the effect of such reduction on yields. Pre-treatment yield assessments were obtained and post-treatment yields are now being obtained. A. T. Ethirveerasingham N35 — Two levels of N (ammonium sulphate) each tested against 4 levels of K on yield trends of eelworm infested fields at Bogawana Group, Boga- wantalawa—3 replicates of 8 treatments in randomized blocks—(1969) Pre-treatment nematode counts in both soil and roots were obtained to­ gether with pre-treatment yield assessments. Post-treatment yield records are now being maintained together with periodical sampling for eelworms. A. T. Ethirveerasingham N36 — Effect of fumigation of 4 different soils on eelworm infestation and growth of young tea, in pots — 6 replicates of 12 treatments in rando­ mized blocks — (1969) This experiment is designed to study the effects of fumigation on different types of soil and to assess the extent of altered growth due to such treatment. Assessments are to be made at the end of one year. A. T. Ethirveerasingham N37 — Comparison of area fumigation with fumigation of planting holes only, using Ditrapex (one level), ethylene dibromide (2 levels), DD (one level) Fumazone (2 levels) as pre-plant treatments for the control of meadow eelworm, at Hindagalla Estate, Namunukula — 3 replicates of 11 treat­ ments—control in randomized blocks — (1969) 106 ANNUAL REPORT FOR 1969 The object of this experiment is the same as in N39. Periodical assess­ ments are to be made to measure growth and eelworm build-up. S. Samarajeewa N41 — Terracur-P (5% granules) at one level, Nemacur-P (10% granules) at one level and Nemagon (20% granules) at 5 levels, in planting holes at planting time at St Coombs Talawakele—3 replicates of 7 treat­ ments-!-control in randomized blocks — (1969) The object of this experiment is the same as in N39 and N40. A. T. Ethirveerasingham Even with the most effective soil fumigants, at relatively high rates of application, eelworms are seldom eradicated and they re-build within relatively short periods. The aim of pre-planting treatments, therefore, is to achieve adequate control over a reasonable period, at least until the plants could es­ tablish satisfactorily in the field. The object of this experiment is to compare the efficacy of area fumigation (complete fumigation) with fumigation of plan­ ting holes only (spot fumigation). The effectiveness of all the treatments will also be compared with methyl bromide treatment (area fumigation) at 1 lb/200 sq.ft. Assessments are to be made at the end of one year. S. Samarajeewa N38 — Age of plants and nematode pathogenicity — 2 clones (one susceptible and one resistant) each with 3 age groups—One half of each set inoculated with meadow eelworms and one half kept as controls, in pots—5 replicates of 14 treatments in randomized blocks — (1969) The object of this experiment is to study the effects of nematode parasitism in plants of different age groups and to see if transplanting older plants would be beneficial. Assessments are to be made at the end of one year, when both growth of plants as well as nematode numbers would be assessed. A. T. Ethirveerasingham N39 — Nemacur-P (10% granules) at one level, Terracur-P (10% granules at 3 levels and Nemagon (20% granules) at 3 levels, in 2 separate sets of treatments, one at planting, the other as post-planting treatment (10 weeks after planting) for the control of meadow eelworm in young tea in pots— 4 replicates of 14 treatments-(-inoculated control and unino- culated control — (1969) The object of this experiment is to evaluate the efficacy of both systemic and non-systemic granular nematicides in reducing nematode damage in young clonal tea and to observe any possible symptoms of phytotoxicity in using such chemicals. Assessments are to be made at the end of one year. A. T. Ethirveerasingham N40— Terracur-P (5% granules) at 2 levels, Nemacur-P (10% granules) at 2 levels and Nemagon (20% granules) at 3 levels in planting holes at planting time at Derryclare Estate, Kotagala—3 replicates of 7 treat­ ments + control in randomized blocks— (1969) ANNUAL REPORT FOR 1969 107 N42 — Terracur-P (5% granules), Nemacur-P (10% granules) and Nemagon (20% granules) each at 2 levels for control of meadow eelworm infesta­ tion in young clonal tea in bearing at Eildon Hall Estate, Lindula—3 replicates of 6 treatments+control in randomized blocks — (1969) The object of this experiment is the same as in N34. Pre-treatment yield assessments are being maintained and treatments are to be applied in 1970. S. Samarajeewa N43 — Four levels of N (ammonium sulphate) each tested against 4 levels of K, on population build-up of meadow eelworm and pathogenicity, in pots—3 replicates of 32 treatments in randomized blocks — (1969) The object of this experiment is to re-investigate the effects of potassium fertilizers on nematode build-up and tolerance of plants to nematode damage (Sivapalan 1969b). Assessments are to be made at the end of one year. A. T. Ethirveerasingham Publications SIVAPALAN, P. (1969). Evaluation of pre-planting nematicidal treatments in young tea plantings. Tea Q. 40,115-118. SIVAPALAN, P. (1969). Further developments in the control of the root- lesion nematode (Pratylenchus loosi) in tea nurseries. Tea Q. 40, 111-114. Reference SIVAPALAN, P. (1969a). Evaluation of pre-planting nematicidal treatment in young tea plantings. Tea Q. 40,115-118. REPORT OF THE ENTOMOLOGY DIVISION Entomologist — W. Danthanarayana, BSc, PhD, DIC General The Division continued to function with no staff in the Research Assis­ tant/Officer grade. Attempts to recruit staff to this grade were unsuccessful. Mr D. C. Weragala, Technical Assistant, assumed duties on 1st April. Mr A. Kathiravetpillai (Technical Assistant) was transferred to the Division of Plant Physiology with effect from 4th December. Dr W. Danthanarayana served on the Standing Committee on Agrochemicals of the Ministry of Agriculture and Food, and also on the Panel for Agrochemicals and Fertilizer of the In­ dustrial Development Board. The Division was very fortunate in obtaining a grant of Rs 384,512/- from the United States Department of Agriculture, under the P.L. 480 Aid Scheme, to conduct research on all aspects of shot-hole borer control. This research grant will cover a period of five years from March 1969. The following important findings were made during the year: (i) a method of controlling live-wood termites of tea, (ii) detection of indigenous predators (exoparasites) of Shot-hole Borer for the first time, (iii) a laboratory technique for rapid clonal testing for shot-hole borer resistance, (iv) a method of pre­ dicting mite outbreaks, and (v) a method of laboratory culture of the Red Spider Mite. Laboratory Investigations * Behavioral Studies on Shot-hole Borer (Xyleborus fornicatus) Differential susceptibility of clones to borer attack The susceptibility of clones TRI 777, 2023, 2024, 2026 and KEN 16/3 to attack by Shot-hole Borer was studied using standard samples (Judenko 1958) of tea stems. Behaviour in gallery construction in relation to position on the stem (node or internode) was also observed. Samples of stems from each clone were exposed to 20 healthy female beetles obtained from unsprayed tea fields for gallery construction. This was replicated 20 times. The results showed very highly significant differences (P < 0.001) in the number of galleries formed in the different clones (Table 1). It was also found that beetles pre­ ferred nodes rather than inter-nodes for gallery construction. This difference too was very highly significant (P < 0.001). TABLE 1 — Gallery construction by female shot-hole borer beetles in different clones under laboratory conditions No. of galleries constructed by 400 Mean No. of galleries Clone beetles in 20 sample stems (y/n—1) At At node internode 74 11 1.8 93 27 1.9 111 35 2.1 161 38 2.3 161 55 2.4 LSD (P < 0.05) 0.1 TRI 2023 TRI 777 KEN 16/3 TRI 2026 TRI 2024 * This research has been financed in part by a grant made by the United States Department of Agriculture under P.L. 480. 108 ANNUAL REPORT FOR 1969 109 The preference for nodes was further examined by field sampling of clonal and seedling tea. The sampling was carried out according to the method of Judenko (1958) by taking 200 stem samples at random. The results showed that about 75 % of the galleries are constructed at the nodes (Table 2). The results on clonal resistance obtained in the laboratory agree very closely with those obtained previously in long-term field experiments (Cal- naido & Kanapathipillai 1967;Thirugnanasuntheran & Calnaido 1968; 1969). It thus appears that the technique developed here is suitable for rapid testing of clones for shot-hole borer resistance. TABLE 2 — Position of shot-hole borer galleries in samples of tea stems brought from different localities Estate and locality Type of tea Percentage galleries at Node Internode Carolina — Watawala Seedling 72.6 27.4 Downside — Welimada TRI 2024 76.4 23.6 Moolgama — Panwilatenne Seedling 77.7 22.3 Kataboola — Kotmale Seedling 72.9 27.1 Ury — Passara Seedling 76.4 23.6 Kataboola — Kotmale Seedling 64.6 35.4 Downside — Welimada Seedling 81.3 18.7 Deltotta — Galaba Seedling 64.6 35.6 Moolgama — Panwilatenne Seedling 79.2 20.8 Kataboola — Kotmale Seedling 75.4 24.6 Telbedde — Badulla TRI 2024 70.3 29.7 Meddecombra — Wategoda TRI 2024 77.1 22.9 Kataboola — Kotmale Seedling 84.4 15.6 Kataboola — Kotmale Seedling 82.3 17.7 Telbedde — Badulla TRI 2024 73.2 26.8 Meddecombra — Wategoda TRI 2024 71.8 28.2 Carolina — Watawala Seedling 65.1 34.9 Downside — Welimada TRI 2024 78.3 21.7 Meddecombra — Wategoda TRI 2024 78.2 21.8 Deltotta — Galaha Seedling 73.5 26.5 Mean 74.4 25.6 Activity of Shot-hole Borer in relation to girth of wood Using the same clones, observations were made on 4-inch-long sample stems brought from the field. One hundred samples were examined for each clone. The samples were dissected to determine the number of occupied galleries, after measurements were made of the diameter at the centre. The results show that the mean diameter of wood preferred for gallery construction is about 1 cm (0.39 in). (Table 3). These observations were further tested under laboratory controlled conditions (30 °C and 64% RH). Twenty healthy female beetles at a time were exposed to 4-inch-long tea stems of different dia­ meters, ranging from 5 to 16 mm. The treatments were replicated seven times for each clone. The results confirm the previous finding based on samples taken from the field (Table 4). 110 ANNUAL REPORT FOR 1969 Mean diameter (mm) for maximum gallery construction Clone TRI TRI KEN TRI TRI Mean 2026 777 16/3 2024 2023 10.8 10.0 10.4 10.4 10.1 10.3 Standard error ± 0 . 4 ± 0 . 2 ± 0 . 5 ± 0 . 4 ± 0 . 4 TABLE 4 — Gallery construction by Shot-hole Borer in relation to girth of wood in the laboratory Mean diameter (mm) for maximum gallery construction Clone TRI TRI KEN TRI TRI Mean 2026 777 16/3 2024 2023 10.4 10.3 10.4 10.3 9.8 10.2 Standard error ± 1 . 1 ± 1 . 1 ± 1 1 ± 1 . 1 + 1.1 Activity of Shot-hole Borer in relation to the age of wood Two types of wood (stems), recognisable as old and new wood, are found in tea bushes attacked by Shot-hole Borer. Old wood refers to stems left over after pruning and new wood to stems formed during the current pruning cycle. The susceptibility of the two types of wood to shot-hole borer attack was studied under controlled conditions (30 °C and 64% RH). Two samples, one from each type of wood, were exposed to 20 female beetles, and replicated ten times for each clone. Results (Table 5) show that new wood is preferred for gallery construction. The difference between the numbers of galleries formed in new and old wood was very highly significant (P < 0.00,1) TABLE 5 — Mean number of galleries constructed in new and old wood by 20 female beetles after 3 days' : exposure Clone TRI 777 TRI 2023 TRI 2024 TRI 2026 KEN 16/3 All clones Mean No. of galleries and standard error New wood Old wood 7.7 5.9 12.1 11.1 8.8 9;3 2.5 2 .0 3.8 3.6 2 .9 3 .0 2 .9 ± 2.6 ± 4 .0 ± 3.5 ± 3.6 -i- 3.3 ± 1.0 0 .9 1.4 1.1 1.2 1.1 Activity of Shot-hole Borer in relation to bark The object of this experiment was to determine whether the beetle pre­ ferred stems with intact bark or stems from which the bark had been peeled off. The experiment was conducted on the same lines as the previous experi­ ment. Results (Table 6) show that beetles prefer stems with bark for gallery construclion. This difference was very highly significant (P < 0.001). TABLE 3 — Gallery construction by Shot-hole Borer in relation to girth of wood in field samples ANNUAL REPORT FOR 1969 111 TABLE 6 — Mean number of galleries made in stems with and without bark by 20 female beetles after 3 days' exposure Clone Mean No. of galleries and standard error With bark Without bark TRI 777 TRI 2023 TRI 2024 TRI 2026 KEN 16/3 13.0 + 1.6 7.8 ± 1.0 21.3 ± 2.3 19.7 ± 2.3 15.7 ± 1.9 15.5 ± 1.8 4.6 ± 0.6 2.3 ± 0.3 6.2 ± 0.3 7.0 + 0.9 5.1 ± 0.7 5.0 ± 0.6 All clones S. N. Fernando Biological control of Shot-hole Borer Different stages of the Shot-hole Borer collected from field experiments were examined for indigenous parasites and predators, and several species of predatory mites were obtained from the bodies of larval, pupal and adult beetles. These were sent to the Commonwealth Institute of Entomology, London, for identification. The first batch of mites sent have been identified as belonging to Family Tarsonemidae (one species) and Family Oribatulidae or Scheloribatidae (two genera) Observations on these mites are continuing. It must be pointed out that this is the first instance in the history of shot-hole borer control that a natural enemy of the beetle has been obtained. As these predatory mites were found only in very small numbers, it appears that they are of no value in a biological control programme. These findings, however, will be of value in the search for possible biological control agents overseas. Some work has also been done in collaboration with the Commonwealth Institute of Biological Control on the possibility of introducing biological control agents from abroad for shot-hole borer control. Five consignments of the Chalcidoid parasite Pemiphora robusta (parasitic on European wood boring beetle Xyloterus domesticus) were received from Switzerland during the course of the year. Altogether 468 wasps were received and released at Caro­ lina Group and Galboda Estate, Watawala. This work is being continued. * Biology of the Red Spider Mite (Oligonychus coffeae) A simple, inexpensive technique was developed to breed the Red Spider Mite in the laboratory. Tea leaf discs, 18 mm in diameter, were maintained in a fresh condition in 2 % sucrose solution in petri dishes and mites reared by depositing individual mites on the leaf discs. Using this method, various stages of the life cycle of the mite were observed and the life history worked out. The life cycle at 21 °C and 74% RH is as follows :— Egg 8 days, protonymph 5.3 days, dentonymph 3.7 days and adult 16 days. Full results have been discussed elsewhere (Kathiravetpillai 1969). * This study has been financed in part by a grant made by the United States Department of Agriculture under Aid Scheme P.L. 480. D. C. Weragala & S. N. Fernando A. Kathiravetpillai 112 ANNUAL REPORT FOR 1969 Studies on Tea Tortrix, (Homona coffearia) Laboratory experiments to supplement field Experiment E56 were carried out on diseases of tea tortrix and the developmental stages of the caterpillar. Bacterial disease Two species of bacteria, one white and the other yellow, were isolated from diseased caterpillars brought from the field. The pathogenicity of the two species was tested using healthy caterpillars, and it was found that the yellow bacterium is pathogenic. Some of the diseased caterpillars are able to pupate, but no moths emerge from these pupae. Cultures of the two bacteria have been sent abroad for identification. Developmental studies Tortrix eggs were allowed to hatch under laboratory controlled conditions, and the larvae that emerged were bred. Observations were made on the dura­ tion and size of each larval instar. In Table 7, these measurements are com­ pared with those obtained from field data. Field measurements were obtained from larvae collected during routine sampling in Experiment E56. The head capsule widths of these larvae were measured, and from the frequency distribution the mean widths and their limits determined. From these data, by regression analysis, the most appropriate measurements of head capsule widths and their 95% fiducial limits have been calculated. These results will be used in the final analysis of results of Experiment ES6. TABLE 7 — Head capsule widths (mm) of tortrix larval ins- tars with their 95 % fiducial limits Instar From measurements From laboratory measurements of field population of cast-skins 1 0.277 + 0.037 0.388 ± 0.104 2 0.565 + 0.013 0.708 ± 0.007 3 0.964 ± 0.008 1. 08 ± 0.333 4 1.392 ± 0.005 1. 58 ± 0.033 5 1.856 ± 0.006 I . 81 ± 0.160 K. D. Bandularatne Field Experiments and Trials The following experiments have been concluded and the results pub­ lished :— E21, E42, E51, E54, E55, E57, E58"and E71 (see Report for 1968; Dantha- narayana 1969; Danthanarayana & Fernando 1970). * Shot-hole Borer E33 — Aldrin, dieldrin and heptachlor for shot-hole borer control in new clea­ rings at Carolina Group, Watawala — (1966) Results up to thj end of the second year have been published (Danthanara­ yana, Fernando & Shanmugam 1968). Results analysed up to the end of the third year also show that the best control of the borer in new clearings is ob­ tained with annual applications of heptachlor (Table 8). This experiment is concluded. * This research has been financed in part by a grant made by the United States Department of Agriculture under P.L. 480. ANNUAL REPORT FOR 1969 113 TABLE 8 — Post-treatment counts of all live stages and open galleries of Shot-hole Borer in Experiment E33 Mean of five counts Treatment Dose Mean No. per 25 units (Vn+l) (lb ai/acre) Live stages' Galleries Heptachlor* 0 .6 20.6 10.0 Heptachlor* 1.7 12.8 6.8 Dieldrin 0.5 24.6 11.3 Dieldrin 1.5 15.9 7.8 Aldrin* 1.5 19.1 8.8 Untreated — 26.9 12.7 LSD (P < 0.05) 3.5 1.3 •Heptachlor and aldrin treatments repeated at intervals of one year E59 — Heptachlor post-prune, heptachlor mid-cycle, heptachlor + Estab, heptachlor + Lovo, heptachlor-impregnated jute, endosulphan and dieldrin for shot-hole borer control at Ury Group, Passara — (1968) The first sampling, taking SO standard units from each plot, was done seven months after spraying and sampling was continued at two-month intervals up to 21 months. Altogether eight examinations were done and the results are presented in Table 9. Post-prune application of dieldrin and mid-cycle application of heptachlor alone showed significant reductions in the number of open galleries. There was, however, no significant difference between these two treatments. When the numbers of all live stages of the beetle were com­ pared, only mid-cycle application of heptachlor differed significantly from the untreated. The results thus indicate that mid-cycle heptachlor application is superior to both dieldrin and heptachlor, applied as immediate post-prune sprays. The addition of stickers, Estab and Lovo, did not improve the per­ sistence of either heptachlor or endrin. This experiment is being continued. TABLE 9 — Post-treatment of counts of all live stages and open galleries of Shot-hole Borer in Experi­ ment E59 Mean of seven counts Treatment Dose Mean No. per 50 units ( V n + 1) (lb ai/acre) Live stages Galleries Heptachlor 1.5 7.4 3.6 Heptachlor+Estab. 1.5 7.3 3.5 Heptachlor+Lovo 1.5 8.6 3.9 Heptachlor—impregnated jute* 2 .0 8.8 4 .2 Heptachlor mid-cycle* 1.5 6.6 3.1 Endrin 1.0 8.3 3.9 Endrin+Estab. 1.0 8.5 3.9 Endrin+Lovo 1.0 8.9 4.1 Endrin-impregnated jute* 1.0 9.9 4 .8 Endosulphan* 0.9 10.0 4 .2 Dieldrin 1.5 7.7 3 .4 Untreated — 8.5 4 .0 LSD (P < 0.05) 1.4 0.5 •Treatments carried out at the end of 10 months after pruning (mid-cycle) 114 ANNUAL REPORT FOR 1969 E60 — Heptachlor, heptachlor+Plyac, heptachlor-impregnated jute, endrin, endrin+Plyac, endrin-impregnated jute, DDT, DDT+Plyac, BHC, BHC+Lovo, fenthion, fenthion+Lovo, and benomyl (Benlate) for shot-hole borer control at Kataboola Estate, Kotmale — (1968) All treatments were carried out 10 months after pruning. Sampling was done on eight occasions at approximately two-month intervals beginning from the fifth month after spraying, by taking 50 standard units from each plot. The results obtained to-date are presented in Table 10. It was found that only the two heptachlor spray treatments gave significant reductions in the numbers of galleries formed. Heptachlor spraying with or without the sticker Plyac was superior to the heptachlor-impregnated jute treatment. When the numbers of all live stages were compared, it was found that all three heptachlor treatments together with the fenthion+Lovo treatment were significantly better than the untreated. Among these four treatments, hepta­ chlor treatments with and without Plyac were significantly superior to the heptachlor-impregnated jute and fenthion+Lovo treatments. The results of this experiments show that the addition of Lovo to fenthion increased its persis­ tence. The experiment is continuing. TABLE 10 — Post-treatment counts of all live stages and open galleries of Shot-hole Borer in Experi­ ment E60 Mean of eight counts Treatment Dose Mean No. per 50 units (Vn + 1) (lb ai/acre) Live stages Galleries Heptachlor 1.5 9.9 5.6 Heptachlor+Plyac 1.5 9.9 5.8 Heptachlor-impregnated jute 2 .0 14.8 7.9 Endrin 1.0 18.0 9.0 Endrin+Plyac 1.0 18.3 8.8 Endrin-impregnated jute. 1.0 17.7 9.5 D D T 5.0 20.2 10.2 DDT+Plyac 5.0 18.3 9.5 BHC 2.0 18.0 8.9 BHC+Lovo 2 .0 19.1 9 .2 Fenthion 1.0 17.4 8.6 Fenthion+Lovo 1.0 14.6 8.2 Benlate 0.125 19.7 10.8 Benlate 0.25 19.2 9.4 Benlate 0.5 19.4 9.5 Untreated — 19.5 9.6 LSD (P < 0.05) 4 .4 2.1 E61 — DDT at 3 levels, DDT+Plyac, endrin at 3 levels, endrin+Plyac, hepta­ chlor, heptachlor+Plyac and dieldrin for shot-hole borer control at Kataboola Estate, Kotmale — (1968) Sampling was done on five occasions up to 17 months after spraying. There was no significant difference between the treatments in respect of damage (total number of galleries) and numbers of all live stages of the beetle. The experiment is concluded. E62 — Three levels of benomyl (Benlate), fenitrothion, fenitrothion+Plyac, endosulphan, endosulphan+Plyac, /M4503, dioxathion, UC 21149 (Temik 10(7) and Du Pont 1179 (Lannate) for shot-hole borer control at Carolina Group, Watawala — 4 replicates of 11 treatments+control in randomized blocks — (1968) ANNUAL REPORT FOR 1969 115 This experiment was carried out for nine months from the time of spraying. Sampling was done by taking 50 standard units from each plot, on four occasions at approximately two-month intervals. Numbers of all live stages, occupied galleries and open galleries were recorded. Statistical analysis of the results indicated that none of the treatments was effective in controlling the borer or in reducing damage. This experiment is concluded. E63 — Endrin, DDT, endrin+DDT, heptachlor, Heptachlor+Tenac, dieldrin, chlordane, perthane, methoxychlor and Resitox at two levels bor shot- hole borer control at Rothschild Estate, Pussellawa — 4 replicates of 11 treatments—control in randomized blocks — (1968) Only two samplings have been carried out so far and the results are in­ conclusive. The experiment is in progress. E64 — VCS506, Dowco 179 (Dursban), formothion, Resitox, DDT at 3 levels, endrin at 3 levels, and C-10015 for shot-hole borer control at Telbedde Estate, Badulla — (1968) All treatments were carried out one year after pruning. The plots were sampled on nine occasions at two-month interval up to 18 months following spraying. Results (Table 11) show that only the lower dose of endrin gave significant reductions in the number of open galleries. When the numbers of all live stages of the beetle were considered, none of the treatments gave significant results. However, the results indicated strongly that the three endrin treatments were better than the. untreated. The experiment is concluded. TABLE 11 — Post-treatment counts of open galleries of Shot-hole Borer in Experiment E64 Mean of nine counts Treatment Dose Mean No. per (lb ai/acre) units( V B + I ) VCS-506 1.00 5.6 Dursban 1.00 6.3 Formothion 1.25 6.1 Resitox ( D D T + 2 . 0 0 + 6.8 endrin) 1.00 DDT 2.50 6.2 DDT 3.75 5.9 DDT 5.00 5.8 Endrin 0.50 4.3 Endrin 1.00 4.6 Endrin 1.50 4 .4 C-10015 2.50 6.9 Untreated .— 5.8 LSD (P < 0.05) 1.5 E65 — Heptachlor, endrin, endosulphan,endosulphan+Plyac, phenthoate, phen- thoate+Plyac, toxaphene, Torbidan, toxaphene-DDT, toxaphene+ Plyac and Miltox for shot-hole borer control at Meddecombra Estate, Watagoda — (1968) This experiment is conducted in a VP clearing planted in 1966. Spraying was done at the end of the second year from planting. Plyac, a polythene- based additive sticker, was used at the rate of two pints per acre. Six examina­ tions, at bimonthly intervals from the time of spraying were dene by taking 50 standard units from each plot. The best results (Table 12) were given by endrin, heptachlor and phenlhoate, which alone were significantly different from the untreated control. There were, however, no significant differences between these three treatments. The experiment is in progress. 116 ANNUAL REPORT FOR 1969 Mean of six counts Treatment Dose Mean No. per 50 units (Vn+D (lb ai/acre) Live stages Galleries Endrin 1.5 12.0 6.8 Heptachlor 1.5 13.9 7.7 Phenthoate 2.5 18.6 9 .2 Phenthoate+Plyac 2.5 21.1 10.4 Toxaphene 6.0 21.5 10.3 Toxaphene+Plyac 6.0 23.9 10.9 Toxaphene+DDT 4 . 0 + 2 . 0 22.6 10.5 Endosulphan 2.6 22.7 10.5 Endosulphan+Plyac 2.6 22.1 10.6 Terbidan (Toxaphene+DDT+ —parathion) 4 . 0 + 2 . 0 + 1 . 0 22.4 10.5 Miltox (Copper+Zineb) 1 . 8 + 1 . 0 23.6 10.4 Untreated — 25.7 10.9 LSD (P < 0.05) 5.5 2 .0 E66 — DDT at 3 levels, endrin at 3 levels, Resitox, heptachlor, heptachlor- impregnated jute, dieldrin and dieldrin-impregnated jute for shot-hole borer control at Deltotte Group, Galaha — 4 replicates of 11 treatments + control in randomized blocks — (1968) All treatments, other than those where dieldrin or heptachlor-impregnated jute were used, were given as post-prune sprays. The insecticide-impregnated jute treatments were given nine months after pruning. Five examinations, at bimonthly intervals were done by taking SO standard units from each plot. The best results (Table 13) were given by dieldrin, dieldrin-impregnated jute and heptachlor-impregnated jute, which alone were significantly different from the untreated control. There were, however, no significant differences between these three treatments. The experiment is in progress. TABLE 13 — Post-treatment counts of all live stages and open galleries of Shot-hole Borer in Experi­ ment £66 Mean of five counts Treatment Dose Mean No. per units ( V n + 1) (lb ai/acre) Live stages Galleries D D T 2.5 18.8 9.3 DDT 3.75 20.4 9.6 DDT 5.0 20.0 9.5 Endrin 0.5 17.8 8.7 Endrin 1.0 17.3 8.6 Endrin 1.5 16.1 8.1 Heptachlor 1.5 16.6 8.4 Heptachlor-jute 2 .0 11.7 6.2 Dieldrin 1.5 13.6 6.9 Dieldrin-jute 2 .0 12.2 7.0 Resitox (DDT+endrin) 2 . 0 + 1 . 0 20.3 9.8 Untreated — 18.6 9.5 LSD (P < 0.05) 4.1 1.5 1969 Experiments E72 — Heptachlor, heptachlor+Plyac at 2 levels, BHC, BHC+JF-2U4, BHC+DS-4443, endrin, endrin+Plyac, Nicabrom, iodfenphos and Padan for shot-hole borer control at Carolina Group, Watawala — 4 replicates of 12 treatments+control in randomized blocks — (1969) TABLE 12 — Post-treatment counts of all live stages and open galleries of Shot-hole Borer in Experi­ ment E65 ANNUAL REPORT FOR 1969 117 Each plot is l/20th acre in extent. The spraying was done with knapsack sprayers using a spray volume of 80 gallons water per acre, one year after pruning. The objects of the experiment are to determine whether the per­ sistence of heptachlor and endrin can be increased by the addition of the sticker, Plyac, at the rates of 1 and 2 pints per acre; to evaluate BHC emul­ sion (Gammalin 20% EC) with and without the spreaders, JF-2184 and DS- 4443 (new compounds); and, to evaluate the new insecticides Nicabrom, iodfenphos (Nuvanol) and Padan (organophosphate compounds). So far only one shot-hole borer assessment has been made. The experiment is in progress. E73 — Heptachlor 40% EC at 2 levels, heptachlor 20% EC, heptachlor+Plyac at 2 levels, heptachlor+JF-21S4, heptachlor+DS-4443, heptachlor+ Emulgator VA at 2 levels, BHC+Plyac and BHC+JF-2M4 for shot- hole borer control at Carolina Group, Watawala — 4 replicates of 11 treatments+control in randomized blocks — (1969) Each plot is l/20th acre in extent. All treatments were given as post- prune sprays, with knapsack sprayers using 80 gallons of water per acre. The object of this experiment is to determine whether the persistence and efficiency of insecticides can be increased by the addition of the stickers, Plyac and Emulgator VA, or by the addition of the spreaders, JF-2184 and DS-4443. The opportunity is also taken to compare a 40% EC formulation of heptachlor with the usual 20% formulation. No sampling has been done yet. The experiment is in progress. E74 — Heptachlor 40% EC at 2 levels, heptachlor 20% EC, heptachlor+Plyac at 2 levels, heptachlor+/F-2184, heptachlor+DS-4443, heptachlor + Emulgator VA at 2 levels, BHC+Plyac and BHC+JF-21S4 for shot- hole borer control at Ury Group, Passara — 4 replicates of 11 treat­ ments + control in randomized blocks — (1969) The details and objects of this experiment are same as those of E73. No sampling has been carried out so far. The experiment is in progress. E7S — Heptachlor, heptachlor+Plyac at 2 levels, heptachlor-impregnated jute, BHC, BHC+JF-21S4, BHC+DS-4443, BHC+Plyac, endrin and endrin+Plyac at 2 levels for shot-hole borer control at Ury Group, Passara — 4 replicates of 11 treatments+control in randomized blocks — (1969) Each plot is l/20th acre in extent. Treatments were given as mid-cycle sprays, 15 months after pruning, using knapsack sprayers and 80 gallons of water per acre. The objects are to evaluate the persistence and efficiency of the insecticides when sprayed with and without additive stickers and sprea­ ders, and to compare 40% EC and 20% EC formulations of heptachlor. Only one sampling has been done so far. The experiment is in progress. E76 — NPK on yield and shot-hole borer damage of clonal tea at Carolina Group, Watawala — 2 replicates of 3 3 — (1969) This experiment is being carried out in collaboration with the Agronomy Division. No results are available yet. C. Shanmugam 118 ANNUAL REPORT FOR 1969 Mites E21 — Mites, shade and fertilizer on yield at Downside Estate, Welimada — (1965) This experiment begun in January 1965 was concluded in September 1968 when the field was pruned. Shaded plots showed higher populations of Red Spider and Scarlet Mites, but there was no significant difference in yield between the shaded and unshaded plots. There was no relationship between mite numbers and different levels of nitrogen, but there were significant differences in yield between nitrogen levels (Table 14). The differences in the numbers of Red Spider and Scarlet Mites in the sprayed and unsprayed plots were highly significant (Table 14). There were also significant differences in yield between sprayed and unsprayed plots, in the second and third years of the cycle (Table 14). TABLE 14 — Response to different levels of nitrogen over pruning cycle (3 years 9 months) in Experi­ ment £21 Level of nitrogen 0 60 120 180 (lb/acre/year Yield 1442 1485 1613 1654 (lb made tea/acre/year) LSD (P < 0. 05) = 101 (P < 0. 01) = 136 (i» < 0.001) = 181 TABLE 15 — Effect of spraying with dicofol (Kelthane) on numbers of Red Spider and Scarlet Mites and yield over one pruning cycle (3 years 9 months) in Experiment E21 Mite No. (log) per 100 leaves Sprayed Unsprayed LSD (P < 0 . 0 0 1 ) Red Spider Mite 2.30 3.35 1.01 Scarlet Mite 2.78 3.88 0.34 Mean yield increase (lb made tea/acre) Year Increase Percentage 1965 10.2 NS 0.6 1966 111.0 *** 5.0 1967 70.8 *** 4.7 1968 —10.4 NS —1.7 *** significant at P < 0.001 E49 — Purple mite attacks on yield and the effects of shade andfertilizer applica­ tions on purple mite numbers at Liddesdale Group, Halgranoya — (1967) This experiment has been concluded. Treated plots consistently showed lower numbers of Purple, Scarlet and Red Spider Mites, but the yield differences were not significant. Fertilizer applications (different levels of nitrogen) did not have any influence on the fluctuations of mite populations. Red spider mite and scarlet mite numbers were higher in the shaded plots, but this difference was not clear in the case of the Purple Mite. Full results will be published in due course, after appropriate statistical analysis. ANNUAL REPORT FOR 1969 119 E50 — Purple mite on yield at Diyanilla Division, Liddesdale Group, Halgra- noya — (1967) This experiment has been concluded. The results were similar to those of E49, and will be published in due course after appropriate statistical analy­ sis. 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, Hapu- tale — (1968) Results with respect to Red Spider and Scarlet Mites were published in the Report for 1968. The degree of purple mite control obtainable with diffe­ rent treatments is given in Table 16. The results show that the three oxythio­ quinox (Morestan) treatments, Plictran and the higher dose of dicofol (Kel- thane 42% EC at the rate of 10 fll. oz per acre) are the most effective in con­ trolling the mites. Since there were no significant differences between these treatments' the lower dose of oxythioquinox (Morestan 25% WP at the rate of 7 oz per acre) and the higher dose of dicofol can be recommended for purple mite control. Plictran which gave extremely good results needs further testing before recommendations can be made. TABLE 16 — Post-treatment counts of purple mite adults in Experiment E67 Treatment Mean No. (n+1) mites per 100 leaves Dose (weeks after treatment is given in (lb ai/acre) parenthesis) Oxythioquinox Oxythioquinox Oxythioquinox Dicofol Dicofol Dicofol+tetradifon Dicofol+tetradifon Tetradifon Tetradifon Dinobuton Plictran Untreated LSD (P + 0.05) (3) (4) (5) (6). 0.11 5.60 4.64 2.77 1.43 0.22 5.97 4.42 2.52 1.55 0.33 5.85 4.32 2.78 1.37 0.26 5.91 4.84 3.15 1.86 0.13 5.68 5.06 3.68 2.98 0 .07+0.025 5.81 4.67 3.63 3.03 0 .13+0.025 6.20 5.24 3.57 2.01 0.025 6.33 5.52 4.65 4.46 0.05 6.21 4.84 4.18 2.35 0.6 5.85 4.20 3.82 3.48 0 .2 5.38 5.50 2.76 1.31 — 6.61 5.74 5.11 4.32 0.50 0.79 1.04 1.54 E68 — Oxythioquinox at 3 levels, dicofol at 3 levels, dinobuton and prolthoate for purple, scarlet and red spider mite control at Welimada Group, Welimada — (1968) The results of this experiment are presented in Table 17. In this experi­ ment the numbers of Red Spider Mite were rather low, and the results with regard to this mite are not very conclusive, but it would seem that all treatments other than prothoate (Fac) gave good results. In the case of Scarlet Mite, dicofol (Kelthane) gave the best results at both dosages, and was superior to oxythioquinox (Morestan) which gave good results at the two higher rates. It is evident that dicofol shows ovicidal action than oxythioquinox. Dinobu­ ton (Acrex) gave consistently good control which did not differ from that of dicofol. As the numbers of purple mites were extremely low the results were not suitable for analysis. 120 ANNUAL REPORT FOR 1969 TABLE 17 — Control of the active stages and eggs of Red Spider Mite and Scarlet Mite of tea with various acaricides at Welimada Group (Ex­ periment E68) Mean number per 100 leaves (corrected for covariance) Treatment Oxythioquinox Oxythioquinox Oxythioquinox Dicofol Dicofol Dinobuton Prothoate Untreated control LSD (P < 0.05) Red Spider Mite Scarlet Mite Active Active Rate stages Eggs stages Eggs (lb ai/acre) l o g ( n + l ) l o g ( n + l ) l o g ( n + l ) l o g ( n + l ) 0.11 2.91 4.50 7.39 7.99 0.22 2.88 4.32 6.56 7.13 0.33 2.38 3.98 6.44 7.11 0.13 3.92 5.47 5.85 6.10 0.26 3.14 4.55 5.76 6.00 0.60 3.02 4.78 6.16 6.72 0.20 4.03 5.04 7.94 8.33 — 4.42 5.81 7.97 8.24 1.23 1.09 0.54 0.54 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 — (1968) The results of this experiment are presented in Table 18. As in the pre­ vious experiment (E68), the numbers of Red Spider Mite were low and the results are not very conclusive. With regard to Scarlet Mite, the best results were obtained with dicofol (Kelthane) which gave consistent by good control of both active stages and eggs. Dicofol performed better at the higher rate of 0.26 lb active ingredient (lOfl. oz of Kelthane 42% MF) per acre. Oxythio­ quinox gave good results, but was inferior to dicofol. As in the previous ex­ periments (E67 and E68), dinobuton (Acrex) and tricyclohexyltin hydroxide (Plictran) gave very good results comparable to those of dicofol and oxythio­ quinox. As the numbers of Purple Mite were extremely low the results were not suitable for analysis. TABLE 18 — Control of the active stages and eggs of Red Spider Mite and Scarlet Mite of tea with various acaricides at Gonamotawa Estate, Haputale (Experiment E69) Mean number per 100 leaves (corrected for covariance) Red Spider Mite Scarlet Mite Treatment Oxythioquinox Oxythioquinox Oxythioquinox Dicofol Dicofol Dinobuton Plictran Untreated control Active Active Rate stages stages Eggs (lb ai/acre) l o g ( n + l ) l o g ( n + l ) l o g ( n + l ) 0.11 4.48 7.37 7.52 0.22 3.63 7.54 7.95 0.33 3.47 7.06 7.15 0.13 3.74 6.58 6.98 0.26 3.67 5.82 6.16 0.60 3.34 6.14 6.96 0.20 3.34 6.86 7.90 — 5.02 8.17 8.52 LSD (P < 0.05) 0.98 0.69 0.81 ANNUAL REPORT FOR 1969 121 Tea Tortrix (Homona coffearia) E56 — The biology and population dynamics of tea Tortrix — (1967) Data for nearly two years are now available, but will be analysed after the experiment is concluded in August 1970. Three species of hyperparasites were found to parasitize Macrocentrus homonae' the parasite of tea tortrix. These have been identified as Ceraphron fijiensis Fen., Eureytoma sp. and Tetrastichus sp. by the Commonwealth Institute of Entomology, London. Studies on the effect of the hyperparasites on Macrocentrus are being continued. K. D. Bandularatne E70 — Loss of crop caused by Tea Tortrix attack — (1968) A heavy tortrix attack was induced by a single round of dieldrin spraying (1.5 lb dieldrin/acre) at the end of 1968. The tortrix attack began in January and continued until July 1969. Plots treated with DDT for tortrix control showed a highly significant yield increase of 23% (Table 19). The difference in the numbers of tortrix larvae found in plots treated with DDT and untreated plots was very highly significant. TABLE 19 — Loss of crop caused by Tea Tortrix—Experi­ ment E70 Yield No. of tortrix larvae Treatment Ob made tea/acre) Sprayed with DDT 573 • 273 ** Untreated control 466 7230 * Significantly different from untreated at P < 0 . 01 ** Significantly different from untreated at P < 0.001 Termites C. Shanmugam 1969 Experiments E77 — Aluminium phosphide (Phostoxiri) at 2 levels, ethylene dibromide, tri- chlorobenzene, dichlorvos at 2 levels, orthodichlorobenzene, dibromo- chloropropane (Nemagon) for the control of Up-Country Live-wood Termite (Postelectrotermes militaris) at Alton Group, Upcot — 4 repli­ cates of 9 treatments+control — (1969). This experiment has been concluded and the results published (Danthana- rayana & Fernando (1970). E78 — Three levels of aluminium phosphide (Phostoxin) for the control of Up-Country Termite Postelectrotermes militaris) at Alton Group, Upcot — 4 replicates of 3 treatments control H—(1969) This experiment has been concluded and the results published (Dantha- narayana & Fernando 1970). E79 — Methyl bromide, aluminium phosphide (Phostoxiri) at 2 levels, BHC smoke generator at 2 levels, dichlorvos, ethylene dibromide at 2 levels, trichlorobenzene at 2 levels, all applied under polythene cover, aluminium phosphide at 4 levels and BHC granules drilled and inserted into the termite colonies for the control of the Low-Country Live-wood Termite (Glyptotermes dilatatus) at Talangaha Estate, Nakiyadeniya — 4 replicates of 15 treatments control H (1969) 122 ANNUAL REPORT FOR 1969 This experiment has been concluded and the results published (Dantha- narayana & Fernando 1970). E80 — Aluminium phosphide (Phostoxin), ethylene dibromide at 4 levels, di- chlorvos in kerosine at 4 levels, zinc phosphide at 3 levels, sodium cyanide (Cymag) at 3 levels, para-dichlorobenzene at 4 levels, trichlorobenzene at 4 levels, BHC granules at 4 levels for the control of the Low-Country Live-wood Termite (Glyptotermes dilatatus) at Talangaha Estate, Nakiyadeniya — 4 replicates of 27 treatments+control — (1969). Each replicate was a single termite-infested bush. The treatments were given by drilling a hole into the gallery system and introducing the chemical. The hole was then sealed with clay so that the effective chemicals, by fumigant action, eliminated the termites within each gallery system. The best results were given by aluminium phosphide, higher doses of ethylene dibromide and para-dichlorobenzene Dichlorvos gave partial control of each colony. Alu­ minium phosphide gave 100% control in all four replicates. Ethylene dibro­ mide was found to be phytotoxic. This experiment is concluded. E81 — Dichlorvos at 2 levels, ethylene dibromide at 2 levels, paradichlorobenzene at 2 levels, BHC granules at 2 levels and trichlorobenzene at 2 levels for the control of the Low-Country Live-wood Termite (Glyptotermes dilatatus) at Talangaha Estate, Nakiyadeniya — 8 replicates of 10 treatments+control — (1969) Treatments were carried out as in experiment E80.—The best results were given by ethylene dibromide which was also found to be phytotoxic. Di­ chlorvos, para-dichlorobenzene and trichlorobenzene were partially effective. None of the treatments gave results as good as those obtainable from aluminium phosphide. This experiment is concluded. S. N. Fernando Lectures DANTHANARAYANA, W. — "Recent developments and current research on pests of tea with special reference to the Low-Country" to the Sabara- gamuwa Planters' Association in June. DANTHANARAYANA, W. — "Live-wood termite problem in the low-country" to the Kegalle Planters' Association in November. DANTHANARAYANA, W. — "Mite outbreaks on tea in the Uva Province and economics of their control" at the 25th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in December. KATHIRAVETPILLAI. A. — "Laboratory culture of the tea red spider mite Oli- gonychus coffeae (Nietn)." at the 25th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in Decem­ ber. Publications DANTHANARAYANA, W. (1969). Population dynamics of the weevil Sitona regensteinensis (Hbst.) in broom. J.Anim. Ecol. 38, 1-18. DANTHANARAYANA, W. (1969). Control of Tea Tortrix Caterpillar in Ceylon. International Pest Control 11,12-16. ANNUAL REPORT FOR 1969 123 DANTHANARAYANA, W. & KATHTRAVETPILLAI, A. (1969). Studies on the eco­ logy and causes of outbreaks of Ectropis bhurmitra Wkr. (Geo- metridae), the twig caterpillar of tea in Ceylon. / . appl. Ecol. 6, 311-322. DANTHANARAYANA, W. & KATHTRAVETPILLAI, A. (1969). Bionomics of Tea Looper, Bistort suppressaria Gn. (Geometridae) Tea Q. 40, 71-83. Acknowledgements The co-operation of the Superintendents and Assistants of estates on which experiments were carried but 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. References CALNAIDO, D . & KANAPATHIPILLAI, P. (1967). Tolerance and susceptibility of tea clones to Shot-hole Borer infestation. Tea Q. 38, 275-281. DANTHANARAYANA, W. (1969). Studies on the ecology and causes of out­ breaks of Ectropis bhurmitra Wkr (Geometridae) the twig caterpillar of tea in Ceylon. / . appl. Ecol. 6,. 311-322. DANTHANARAYANA, W. & FERNANDO, N. (1970). A method of controlling termite colonies that live within plants. International Pest Control 12, 10-14. JUDENKO, E. (1958). Trials with a method of assessment of infestation caused by Shot-hole Borer on old tea. Tea Q. 29, 51-59. TKRUGNANASUNTHERAN, K. & CALNAIDO, D . (1968). Field observations on the tolerance and susceptibility of tea clones to shot-hole borer infestation. Tea Q. 39, 6-10. THKUGNANASUNTHERAN, K. & CALNAIDO, D . (1969). Observations on the tolerance and suceptibility of tea clones to Shot-hole Borer infesta­ tion 1969. Tea Q. 40, 47-52. REPORT OF THE BIOCHEMISTRY DIVISION Acting Biochemist — R. R. Selvendran, BSc, PhD General The Biochemist, Dr R. L. Wickremasinghe, left Ceylon on 24th November for post-doctorate research at the Massachusetts Institute of Technology, Massachusetts, Cambridge, USA. He was awarded a Fulbright Research Fellowship by the United States Educational Foundation in Ceylon. Dr R. R. Selvendran, Research Officer, acted for the Biochemist from that date. Dr G. R. Roberts, Research Officer, returned to the Island on 3rd October after successful completion of his post-graduate studies at the Botany Department, Imperial College, London. His doctoral thesis dealt with the "Permeability of the chloroplast membrane to photosynthetic intermediates". Mr W. A. B. de Silva, Technical Assistant, left the services of the Institute on 31st December. Laboratory Investigations Metabolism of choline and related compounds in the tea plant It has been suggested that phosphoryl choline is an important phosphate carrier in higher plants (Maizel et al 1956). An ion-exchange chromato­ graphic procedure was, therefore, developed for the isolation of choline and its derivatives from different organs of the tea plant. The flush and mature leaves contain appreciable quantities of choline and phosphoryl choline and traces of two tertiary bases having Rf values 0.33 and 0.18 respectively in phenol/water. Feeder roots contain phosphoryl choline, but no detectable quantity of choline. Two tertiary bases having Rf values 0.50 and 0.32 respectively in phenol/water were also detected. Choline was rapidly oxidised to betaine by tea shoots in diffused light. The practical implications of this study are being investigated. R. R, Selvendran Translocation of phosphate by tea plants The translocation of phosphate in the tea plant was studied because of its possible importance in the utilization of root reserves. Knootz & Biddulph (1957) using kidney besfn plants have shown that foliar-applied phosphorus was translocated and Stored in roots. The present workfwith tea plants compares translocation of phosphorus following foliar application with stem injection methods. When autoradiograms were made of pressed whole plants, the exposure, development and reproduction were uniform so that direct comparisons could be made. For radioactive assay, the various plant sections were oven-dried, ground to a fine powder and counted. The activity applied per plant was between 100 and 200 (uc and was constant within each experimental run. P 3 2 phosphate will be referred to as P*. Foliar application of P* to tea plants resulted in only very slight move­ ment of the phosphorus out of the leaves, even after three weeks of application. A comparable experiment with a herbaceous plant, however, showed free movement of P* within the plant in 36 hr. Effect of daily spraying offoliage on the phosphorus concentration of roots 124 ANNUAL REPORT FOR 1969 125 Four uniform plants (2-year-old) grown in cement pots were used for this investigation. Two of the plants were sprayed daily for 15 days, with un­ l a b e l e d 30mM KH 2P0 4, while the other two were sprayed with distilled water. Both the upper and lower surfaces of every leaf were sprayed twice daily. No injury from the spray was observed. After harvesting, the roots were washed with distilled water, oven-dried and analysed for total phosphorus. No significant increase in the phosphorus content of the roots of phosphorus- treated plants was noted. Stem injection of phosphorus Phosphorus (P*) injected through the cut ends of stems of plants re­ covering from pruning, was found to move readily down the stem and into developing shoots. In one experiment P* was injected into a young tea plant (15 months old) soon after pruning and the whole plant autoradiographed after recovery ( 2 months from the time of pruning). Radioactivity was detected throughout the plant and was found to be concentrated in the growing shoots. From these studies, it appears that very little foliar-applied phosphorus moves into the plant, while stem-injected phosphorus moves freely within the plant. R. R. Selvendran Xylem exudate of tea plants A method was developed for collecting xylem sap from tea plants in quan­ tities sufficient for analysis. Organic nitrogenous compounds accounted for most of the nitrogen present in the sap. Glutamine, theanine, glutamic acid, aspartic acid and lysine were quantitatively, the most important nitrogenous compounds. Leucine/isoleucine, phenyl alanine, valine and asparagine were also present in lesser amounts. Other compounds present included inor­ ganic phosphate, sulphate, glucose, fructose and sucrose. Phosphoryl choline was not detected. During recovery from pruning, there was a definite change in the propor­ tions of some of the constituents in the sap. The results are given in Table 1. The total amino acid content decreased to a very low level 9 days after pruning, followed by an increase with bud-break. Glutamine and theanine were the most important constituents quantitatively. These tended to decrease rela­ tively more than the other amino acids during the first few days after pruning. The increase in glutamine and to a lesser extent theanine was more marked with bud-break. Phosphoryl choline was not detected in the sap at any stage during the recovery period. The changes in the level of phosphate, sulphate and sugars were somewhat parallel to the changes in the level of amino acids. All these constituents decreased to a low level a few days after pruning and increased with bud-break. These findings suggest that new growth was made largely at the expense of translocated nitrogenous and other compounds. 126 ANNUAL REPORT FOR 1969 TABLE 1—The composition of the amino acids in the sap as q moles/ml during recovery from pruning of clean-pruned plants No. of days from priming Compound 0 4 9 22 33 64 Glutamine 2.84 0.52 0.06 0.33 1.02 1.40 Theanine 1.26 0.43 0.01 0.05 0.45 0.80 Glutamic acid 0.09 0.06 0.04 0.10 0.18 0.22 Aspartic acid 0.04 0.03 0.04 0.05 0.06 0.11 Lysine 0.09 0.03 0.01 0.04 0.08 0.11 total amino acid 4.84 1.38 0.20 0.65 1 9 1 3.43 R. R. Selvendran Acetate metabolism during black tea manufacture Earlier work has shown that C 1 4 labelled L-leucine fed to tea shoots was converted to mevalonic acid and volatile compounds containing mainly terpenes during tea manufacture (Wickremasinghe & Sivapalan 1966). Terpenes could also be formed in plant tissues from acetic acid by way of mevalonic acid. An investigation was therefore undertaken to study the fate of C 1 4 labelled acetate in tea shoots during manufacture. Acetate-l-C14 and acetate-C14 (U) were separately fed to excised tea shoots and the transformations studied. Of the known amino acids in tea shoots, the following were labelled: aspartic acid, glutamic acid, glutamine, threo­ nine, alanine, n-ethyl asparagine and leucine. Theanine was not labelled. The patterns of labelling in the withered, fermented and fired samples were comparable. In the withered sample all, the flavanols except epicatechin gallate were labelled. The intensity of labelling of the flavanols decreased appreciably on fermentation. Of the volatile compounds which had pro­ perties of terpenes, four were labelled. They have not been identified. Of the known organic acids in tea shoots, citric, malic and succinic, acids were labelled, while oxalic acid was not labelled. The patterns of labelling of the acids in the withered, fermented and fired samples were comparable, except for the detection of mevalonic acid in the fermented sample! The point of inter­ est here is that detectable quantity of labelled mevalonic acid was formed only at the fermentation stage. This suggests the participation of acetate in the formation of terpenes during this period. ; K. Sivapalan Studies on the utilization of root reserves An investigation was undertaken to identify the major sugars of tea roots and the changes which they undergo during recovery from; pruning. Tea roots contain glucose, fructose, sucrose, raffinose and stachyose. Glucose, fructose and sucrose were present in appreciable quantities, while raffinose and stachyose were less abundant. During recovery frofn pruning, there was a marked decrease in the total sugars. Raffinose and stachyose decreased to a very low level. The concentration ,of sucrose was greater than glucose plus fructose immediately after pruning. With bud-break there was a 50% de­ crease in the level of sucrose and a slight change in the level of glucose plus fructose. The major amino acids of tea roots, namely' theanine, n-ethyl asparagine, glutamine, glutamic acid and aspartic acid increased during the recovery period. ANNUAL REPORT FOR 1969 127 It appears that starch reserves are broken down to glucose and fructose by way of sucrose, converted to amino acids in the root system and then trans­ located to support growth of new shoots. B. P. M. Perera Analysis of cream of tea infusions A detailed analysis of the cream from high-grown tea was carried out. This study not only confirmed that the principal constituents of cream are theaflavin gallate (theaflavins), thearubigins and caffeine, but also showed that the cream-complex contains smaller quantities of amino acids, organic acids and inorganic material. The effect of the pH of the infusion on the quantity of cream formed was also investigated. The fact that the cream could be washed with distilled water without removal of all the amino acids and organic acids shows that these compounds are linked to the cream-complex by residual valencies. The organic and amino acid analysis of the cream showed several similarities to black tea. S. Jayaratnam Distribution of polyphenols and amino acids in a six-leaved tea shoot A distinctive feature of the tea plant is the accumulation in its leaves of large quantities of various polyphenolic compounds. Tea flush contains a high concentration of polyphenols (and amino acids) that makes manufacture of black tea from them possible. It has been shown by Sanderson & Sivapalan (1966) that leaf age had a marked effect on the type of compounds elaborated by the tissue. An investigation was, therefore, undertaken to study the distri­ bution of polyphenols and amino acids in the shoot (bud, first leaf, second leaf, etc and stem). Absolute and aqueous (60%) methanol were successively used as extracting solvents to assess the degree of oxidation and condensation of polyphenols (Wickremasinghe & Swain 1965). Tea shoots (clone TRI 2026) which are in an active state of free growth as in the case of bushes which are allowed to grow out for the production of cuttings were used. The shoots were divided into buds, first, second, third leaves, etc and stem and analysed separately. The results are given in Table 2. It is noteworthy that simple polyphenols are most abundant in the first and second leaf and fall off in concentration in the older leaves. The concentra­ tion of the oxidised polyphenols, however, is higher in the third leaf down­ wards compared with the bud, first and second leaf. The stem is sharply dis­ tinct from the rest of the shoot in this respect. The total amino acid concen­ tration decreased in the older leaves. TABLE 2 — Concentrations of polyphenols and amino acids in a six-leaved tea shoot as mg/g dry wt Absolute methanol Aqueous methanol (60%) Total amino acids Bud 226 9 .2 10.0 1st leaf 324 8.4 10.1 2nd leaf 275 15.7 9.4 3rd leaf 251 32.8 5.5 4th leaf 221 28.3 4.5 5th leaf 227 27.9 2.6 6th leaf 232 29.2 1.7 Unlignified stem 57 15.3 7.5 B. P. M. Perera 128 ANNUAL REPORT FOR 1969 Further investigations on the proteins of tea In the previous report, separation of the proteins of tea flush by paper electrophoresis was reported. These studies were extended to fractionation of the nitrogenous constituents on Sephadex columns. Tea extracts were passed through Sephadex columns and the nitrogen content of the effluent was determined by the micro-kjeldhal method. A plot of the nitrogen con­ centration in the effluent against fraction number, showed two main peaks, the first representing the protein fraction and the second, the non-protein nitrogenous compounds like caffeine, amino acids etc. The protein fraction was hydrolysed and the liberated amino aicds were identified by paper chromato­ graphy. The main amino acids of tea proteins were leucine/isoleucine, gluta- mine, glutamic acid, aspartic acid, asparagine, phenyl alanine and serine. All these amino acids increase during withering of tea shoots and it is proable that they are breakdown products of the proteins. U. L. L. de Silva Studies on the polyphenol oxidase of tea It has been known for a long time that the polyphenolic constituents in tea shoots play an important role in black tea manufacture. The detection of an active oxidase system and the nature of the oxidation products have been the subject of many investigations. However, the substrates of the oxidase system and the extent to which the reaction products contribute to colour formation during fermentation remain poorly understood. The present study was aimed at elucidating some of these phenomena. (a) Methods for the isolation of tea polyphenols Three main procedures were tried to isolate polyphenols from tea leaf. (1) Extraction with diethyl ether This solvent extraction procedure was selected because it extracted only the vanillin-reacting polyphenols (flavanojs), which are the main substrates for the oxidase system. Tea shoots were macerated with diethyl ether and the extract filtered and dried with anhydrous sodium sulphate. The ether soluble polyphenols were recovered by evaporation of the ether and taken up in water. (2) Method using hide powder Polyphenols from aqueous extracts of tea leaf were preferentially adsorbed on hide powder and eluted with absolute and 50% aqueous acetone. The eluate contained in addition to the flavanols all the tannins present in the extract, eg leucoanthocyanins and true tannins like corilagin and chebulinic acid. (3) Method using polyclar The procedure was similar to Method 2, except that polyclar was used as the adsorbant instead of hide powder. The eluate contained in addition to flavanols and tannins, all the glycosides as well. Chlorogenic acid and theogal- Iin were very weakly absorbed by polyclar. (b) Some reactions of polyphenol oxidase The soluble enzyme was prepared by the procedure described by Sanderson (1965) and a preliminary study was made of the enzymic oxidation of the individual flavanols and. other phenolic compounds on paper at various pH values. The optimum activity (in terms of the development of colour) was shown at pH 5.6. ANNUAL REPORT FOR 1969 129 (1) Enzymic oxidation of individual flavanols The flavanols were separated on paper and the dried chromatograms were dipped in the fresh enzyme extract. The spots were seen to develop various colours at different rates. The coloured spots were cut and eluted off the paper with warm water and identified by paper chromatography. The results are given in Table 3. Enzymic oxidation of mixed substrates was studied using the Warburg manometric method and the reaction products identified by paper chromato­ graphy. (2) Inhibitors of tea polyphenol oxidase A detailed study was made of the naturally occurring inhibitors of the oxidase. The water soluble extracts from a wide variety of plants were studied for their ability to inhibit the enzyme. Of the plants examined, extracts from pericarp of myrobalan fruits and shoots from poor-fermenting clones were found to be good sources of the inhibitor. TABLE 3 - Substrate Epigallocatechin Epigallocatecbin galiate Epicatechin galiate Epicatechin Catechin Rutin Chlorogenic acid Enzymic oxidation of tea flavanols by polyphenol oxidase Products Polyphenol-protein complex Theaflavms, tricetinidin Polyphenol-protein complex Polyphenol-protein complex Polyphenol complex Polyphenol complex Polyphenol-protein complex Colour Orange yellow Orange yellow Bright yellow Greenish yellow Orange yellow Dull brown Dull brown The rates of formation of the coloured products on paper were noted. Epigallocatechin was much slower compared with the other substrates. K. P. W. C. Per«a Effect of irradiation on storage of tea Comparative studies were made of irradiated and unirradiated tea during storage. The irradiation was under short wave ultra-violet light for four hours and the factors studied were micro-organisms and polyphenols. The tea was stored in sterilized bottles and examined for micro-organisms by culturing the contents. An infusion made from the same sample was studied by paper chromatography. The most interesting observation so far made was the appearance of phloroglucinol during storage of unirradiated tea. It is possible that this compound is a breakdown product of epigallocatechin galiate and theaflavin galiate by fungal enzymes. The evidence for this hypo­ thesis is, however, meagre. W. A. B. de Silva Lectures, Symposia and Visits DE SILVA, U. L. L. — "An investigation of the proteins of tea", at the 25th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in December. 130 ANNUAL REPORT FOR 1969 DE SILVA, W. A. B. — "A comparative study of chemical analyses of different varieties of tea" at the 25th Annual Sessions of the Ceylon Association for the Advancement Of Science at Colombo in December. PERERA, K. P. W. C. — "A study of the enzymic oxidation of tea polyphenols and the inhibitory effect of tannins on the enzyme reaction" at the 25th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in December. ROBERTS, G. R., KEYS, A. J. & WHITTINGHAM, C. P. — "Permeability of the chloroplast membrane to photosynthetic products in vivo" at the Society of Experimental Biology at York, U K , in July. ROBERTS, G. R., KEYS, A. J. & WIHTTTNGHAM, C. P. — "In vivo studies of photosynthetic intermediates" — at the 25th Annual Sessions of the Ceylon Association for the Advancement of Science at Colombo in December. SELVENDRAN, R. R. — "Effects of artificial wilting of tea shoots and strawberry leaves on the metabolism of phosphate esters and nucleotides" at the 25th Annual Sessions of the Ceylon Association for the Advance­ ment of Science at Colombo in December. SIVAPALAN, K. — "Acetate metabolism during tea manufacture" at the 25th Annual Sessions of the Ceylon Association for the Advance­ ment of Science at Colombo in December. Publications KEYS, A. J. & ROBERTS, G. R. (1969). The use of cellulose phosphate in the extraction of free nucleotides from plant tissue. Biochem.J. 114,16-17. SELVENDRAN, R. R. (1969). Metabolism of nucleotides and phosphate esters in tea shoots during black tea manufacture. Tea Q. 40,93-98. WICKREMASINGHE, R. L., PERERA, B. P. M. & SILVA, U . L. L. (1969). Studies on the quality and flavour of tea. 4—Observations on the biosyn­ thesis of volatile compounds. Tea Q. 40, 26-50. References KOONTZ, H . & BIDDULPH, O. (1957). Factors affecting absorption and translocation of foliar applied phosphorus. Plant Physiol. 32, 463-470. MAIZEL, J. V., BENSON, A. A. & TOLBERT, N. E. (1956). Identification of phosphoryl choline as an important constituent of plant saps. Plant Physiol. 3 1 , 407-408. SANDERSON, G. W. & SIVAPALAN, K. (1966). Effect of leaf age on pho­ tosynthetic assimilation of carbon dioxide in tea plants. Tea Q. 37, 11-26. SANDERSON, G. W. (1964). Extraction of soluble catechol oxidase from tea shoot tips. Biochem. Biophys. Acta. 92, 622-624. WICKREMASINGHE, R. L. & SIVAPALAN, K. (1966). The role of leucine in tea flavour. Abstr. Proc. Ceylon Ass. Advnc. Sci. 4 47. WICKREMASINGHE, R. L. & SWAIN, T. (1965). Studies on the quality and flavour of Ceylon tea. J. Sci. Fd Agric. 16, 57-64. REPORT OF THE TECHNOLOGY DIVISION Technologist — D. Kirtisinghe, BSc, PhD, DIC, C Eng, AMIChemE General Research posts in the Division were poorly manned at the main station as well as at the Low-Country Station. The Development Engineer resigned early in the year causing a further set back to the programme of tea machinery development of the Tea Research Institute. Despite advertisement, the Institute was unable to fill the vacancies created by this resignation as well as four other posts in this category. The Institute was also unable to find a suitable candidate to fill the Tea Taster's post and alternative arrangements are now being made to select and train a suitable candidate from within the Institute's service. For want of a tea taster the number of samples for evaluation were drastically reduced and these were evaluated by the Institute's tea tasting panels in Colombo. The Technology units at Kottawa and Passara continued to be closed as it was not possible to accommodate samples from these units in the panels at the Institute's disposal. The services of Mr G. H. Ellis have been kindly loaned by the British High Commission to the Institute under the auspices of the Colombo Plan Technical Aid Scheme. Factory Experiments Experiments Tl to T3, T5 to T31 and T33 to T35 have been concluded. High-country experiments (St Coombs) T4 — Quality assessment of new clones — (1966) During the year under review no new clones were tested for quality because of the difficulties encountered with sample evaluation. T32 — Drier Project — (1967) Progress on this drier was hindered to some extent because of some difficulties that arose regarding ownership of this machine. These were finally ironed out during the latter part of the year and the flat bed section erected at St Coombs for further testing, with engineering assistance from Messrs Colombo Commercial Co., Ltd. It is expected that the machine would be ready for further trial by January, 1970. G. H. Ellis, W. C. A. de Silva & W. A. C. de Silva 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) with clones DT 1 and TRI 777 (Group 1 classifi­ cation) is financially a worthwhile proposition. Blending was carried out both before and after manufacture, on a miniature scale. The blends and the straight clonal teas were : 131 132 ANNUAL REPORT FOR 1969 Duplicate samples of the B O well as by two tasters in Colombo. P grade were evaluated by the TRI taster as A summary of the results is as follows : TRI taster Infusion Colour Strength Quality Valuation (cts) Pure clonal 2025 777 DTI 4.4 6.3 6.5 4.6 6.2 5.2 4.5 5.7 5.6 5.0 6.4 6.8 220 332 341 Blended in the rollers 2025 2025 2025 777 DTI DTI 777 5.5 5.5 5.8 4.7 5.0 4.8 5.5 5.5 5.9 5.5 5.3 5.8 271 258 297 Blended after manufacture 2025 2025 2025 777 DTI DTI 777 5.5 5.6 5.7 5.1 5.1 4.9 5.6 5.6 271 273 5.7 5.3 5.0 5.6 274 Colombo tasters Infusion Colour Strength Quality Valuation (cts) Pure clonal 2025 777 DT 1 3.0 5.8 5.8 4.3 6.8 5.1 4.5 5.2 4.7 4.1 4.4 4.0 215 221 213 Blended in the rollers 2025 2025 2025 777 DT 1 DT 1 777 4.3 4.0 5.1 6.2 4.6 5.7 5.2 4.6 4.8 4.2 4.0 3.8 221 218 211 Blended after manufacture 2025 2025 2025 777 DT 1 DT 1 777 4.2 4.1 5.9 4.8 4.8 4.1 4.7 4.2 219 218 4.4 6.0 4.9 4.1 218 1 — TRI 2025 2 — TRI 777 3 —DT 1 4 — TRI 2025 and TRI 777 mixed in the ratio of 1 : 1 in the roller 5 — TRI 2025 and DT 1 mixed in the ratio of 1 : 1 in the roller 6 — TRI 2025, TRI 777 and DT 1 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 manufacture 8 — TRI 2025 and DT 1 mixed in the ratio of 1 : 1 after manufacture, and 9 — TRI 2025, TRI 777 and DT 1 mixed in the ratio of 1 : 1 : 1 after manu­ facture. ANNUAL REPORT FOR 1969 133 Experimental evidence indicates that the Colombo tasters are unable to distinguish between these particular clones whether blended before rolling or after manufacture. The overall picture presented by the TRI taster's finding was also somewhat similar. The experiment is, however, to be repeated with other mixtures of clones in order to have sufficient experimental evidence to draw generalised conclusions. S. Samarasingham 1969 Experiments T37 — The effect of spraying a copper fungicidal preparation at different levels, on made tea characteristics — (1969) The Division gave assistance to Dr R. L. de Silva to determine the effect of spraying a copper fungicide at different dosages on made tea characteristics. The evaluations of the BOP grade by a panel of tasters in Colombo are as follows: Dosage of copper fungicide in oz/acre/week 0 1/16 1/8 1/4 1/2 1 2 8 Infusion 4.07 4.02 4.17 4.31 4.16 4.44 4.05 4.21 Colour 4.41 5.14 4.82 4.42 4.75 4.93 4.63 4.81 Strength 4.28 4.54 4.35 4.13 4.39 4.68 4.49 4.54 Quality 3.60 3.57 3.43 3.47 3.75 3.81 3.72 3.28 Valuation (cts) 162 167 159 158 174 176 166 174 The results indicate that the tasters are unable to detect effects on made tea characteristics due to spraying of copper fungicides even at dosages of 8 oz/acre/week. S. Samarasingham T38 — Manufacture properties of teas manured with three types of nitrogen at two different levels — (1969) Experiments were carried out in collaboration with the Agricultural Chemist to determine the influence of fertiliser applications on made tea characteristics. The three types of fertiliser were: (a) Ammonium sulphate (b) Calcium ammonium nitrate, and (c) Urea. Each of these fertilisers were applied at two different levels of nitrogen (150 lb N and 300 lb N). Teas were manufactured on 11 occasions on a miniature scale and eva­ luated by a panel of five tasters in Colombo. Results indicate that the treated teas are not different with respect to all made tea characteristics. W. A. C. de Silva 134 ANNUAL REPORT FOR 1969 T39 — Effect of storage of tea in air-tight plastic containers — (1969) Screw top polystyrene and polyethylene tea sample containers were tested in co-operation with a panel of tea tasters in Colombo. The aim was to determine their suitability for use as an alternative to aluminium tins by the industry. Tasting reports indicate that there is no difference between the teas packed in plastic and aluminium containers. Wei­ ghts of these containers and their respective volumes compared with aluminium tins, are as follows : Type Weight Volume (g) (ml) Polyethylene 30.1 192 Polystyrene 32.1 192 Aluminium 18.9 115 Tea in plastic containers after a storage period of three months showed an increase in moisture content ranging from 0.5 to 1 % over that of the alumi­ nium containers. The plastic containers are considered to be strong and the damage in transit is likely to be negligible. Their use could be recommended. W. C. A. de Silva T40 — Comparison of Keegel cone with Rettie cone — 15 replicates of 2 treat­ ments—(1969) This experiment was carried out to assess the performances of Keegel and medium Rettie cones. The two types of central fittings were installed on two similar 45-in. rollers having crescent battens. Roller charges of 325 lb each were used to determine the performance of the two types of central fit­ tings with respect to: (a) 1st and 2nd dhool outturns (b) grade outturns (c) roller temperatures, and (d) made tea characteristics of the BOP grade obtained from the 1st and 2nd dhools. ' Experiment was concluded in December after carrying out 15 replicates. Some of the tasters' evaluations of the samples are still to be received. Once these are available steps will be taken to analyse the results. W. A. C. de Silva & T. Alawattegama T41 — Use of cone attachment in an S-in. Rotorvane using clonal leaf—(1969) The aim of the experiment was to determine the best position of the cone attachment for the production of RV/orthodox teas. The Rotorvane used in this experiment was originally of the type A and which had been later modified to the type B with the iris end plate. For the purpose of the present investigation this Rotorvane was modified to take in the cone attachment, which comprises of two components: (1) A convergent divergent sleeve inserted in the stator or cylinder of the Rotorvane at its discharge end; and ANNUAL REPORT FOR 1969 135 (2) A battened, truncated cone fixed to the rotor shaft at the discharge end between vanes and the trunion. The base of the cone was in contact with the trunion. Three sets of resistors at the discharge end were removed in order to accommodate the adjustable convergent divergent sleeve. The truncated cone replaced two sets of vanes and the iris end plate. After these modifications, the rotor shaft had seven forward vanes followed by the truncated cone. Total movement of the sleeve parallel to the axis of the rotorvane is 1J in. and this could be achieved in six revolutions of the adjustable ring. Insertion of the sleeve to the innermost limit induces minimum pressure and the with­ drawal of the sleeve away from this position increases the degree of pressure. Three positions of the sleeve corresponding to maximum, medium and minimum pressure were investigated in this experiment. Batches of leaf weighing 275 lb for each of the treatments were used throughout the trial. Method of rolling used was identical to that given in Programme 1 under "Rotorvane Manufacturing Techniques" (De Silva & Sanderson 1964). BOP and BOPF samples were evaluated by a panel of tasters in Colombo. Experiment was concluded in December. Results have yet to be analysed. W. C. A. de Silva T42 — Use of cone attachment in an 8-/«. Rotorvane using seedling leaf—(1969) This experiment was carried out concurrently with that of experiment T41. The experimental procedure was similar to that of experiment T41. Results have yet to be analysed. T43 — Manufacturing properties of bi-clonal crosses — (1969) In collaboration with the Plant Breeder a total of 61 new selections planted out as clones in observation plots were manufactured by the mincing machine technique, during July-September, 1969, for preliminary quality assessments. Samples were tasted by a member of the Division and the' outstanding ones were reassessed by Mr C. H. Wickremesinghe of Consolidated Exports Cor­ poration. Fifteen of these clones appear to be comparable, if not better, with clone DT 1, with respect to quality. A point of interest is that all except two of these fifteen were progenies of either clone TRI 777 or clone DT 1 (Group 1 clones). A. Thevathasan & W. C. A. de Silva T44 — Variation of total soluble solids of wet and fired dhools with period of fermentation — (1969) This experiment was carried out to determine whether total soluble matter in wet and fired dhools could be taken as an index in determining the optimum period of fermentation. At the same time the possibility of corelating the percentage soluble matter with strength of liquor was explored. Results were obtained from both clonal and seedling leaf. Periods of fermentation investigated were J, 1,1|, 2,2\, 3, Z\ and 4 hr. As this was only a preliminary investigation, experiments were carried out only with the 1st dhool. Results indicated that there was a variation with period of fermentation but the pattern was not regular to draw any conclusions. Errors in sampling could not be ruled out in this particular trial and it is hoped to repeat this experiment with more uniform material. S. Jayaratnam 136 ANNUAL REPORT FOR 1969 T45 — Green tea — (1969) Green tea was manufactured from leaf samples collected from several tea-growing districts in Ceylon at St Coombs. No special effort was made to obtain leaf which was different from that of normal estate standard, nor was any special attempt made to select estates from each district. The samples were evaluated by two Japanese tasters who have had long connection with the tea industry of that country, but they were not profes­ sional tasters. Their evaluations given under, therefore, serve only as an approximate guide: It is, therefore, evident that the best samples of green tea have originated from Rakwana, Kandy and Ratnapura. In this preliminary survey Kandy and Rakwana were selected on the advice of the Biochemist for reasons based on analytical findings. It is also interesting to note that the best green tea samples have originated from areas which do not traditionally make the best liquoring black teas. S. Samarasingham & T. Alawattegama T46 — Dry matter content of some clones — (1969) 12 Clones (3 from each of the quality groups) were selected. Plucking was on a 7-day round. Percentage dry matter content of the clones were determined in duplicate at weekly intervals over a period of three months beginning from September, 1969. The average percentage dry matter and the 5% confidence limits are as follows: Quality group Clone Percentage dry matter 1 TRI 777 21.14 ± 0.26 DT 1 18.97 ± 0.32 NL 4/2 20.72 ± 0.41 2 TRI 2024 20.21 ± 0.39 TRI 2027 18.97 ± 0.26 K 136 19.71 ± 0.24 4 TRI 2025 20.29 ± 0.38 MT 18 20.64 ± 0.38 CH 13 20.05 ± 0.36 5 TRI 2026 18.99 ± 0.27 TRI 2043 18.65 ± 0.35 PA 22 19.02 ± 0.52 A. Thevathasan Low-country experiments (St Joachim) Experiments LT1 to LT7 have been concluded. LT8 — Live shade on the manufacturing properties of tea — (1967) Sample No. 1 2 3 4 Origin TRI St Coombs TRI St Coombs Nuwara Eliya TRI St Coombs Kandy Rakwana Leaf kind Assam China China China China China Plucking impression coarsest finest coarse coarse fine 40 Style colour 10 buffalo 20 33 31 39 well twisted shine 40 green 7 8 9 10 11 TRI St Joachim Kandapola TRI St Coombs TRI St Coombs TRI St Coombs Assam China Assam shade Assam no shade China manured fine common commonest coarsest coarse 37 35 yellowish 18 Bancha smell 26 Bancha 29 I Opinion 20 Flavour 20 Liquor 20 Taste Infused leaf Total /100 Evaluation Rs/ktg 10 strange smell 13 red 13 bitter burnt 46 15 Assam smell 16 red 15 bitter burnt and dark 66 6.7 13 14 15 yellow dark 75 8 15 Bancha smell 16 red 15 bitter yellow 78 7.5 20 flavoury aroma 19 red clear 19 bitter rough green yellow 97 11 19 cool 20 gold red clear 20 yellow green 99 11-12 19 cool 17 gold 18 bitter greenish 91 10 17 cool 18 gold 19 yellow 89 9 16 cool 18 gold 16 greenish yellow 68 6.3 13 17 yellow 15 yellow 61 5.8 19 aroma 19 gold clear 18 body yellowish green 85 6.7 > > J* ta 13 O ?o H •n o VO 138 ANNUAL REPORT FOR 1969 The experiment has. been concluded, but results have not been analysed as the officer carrying out this experiment is on overseas study leave. T. F. Saldin LT9 — Drier project — (1967) See T32 G. H. Ellis, W. C. A. de Sirva & W. A. C. de Silva LT10 — Instant tea — (1968) See Report of the Biochemistry Division. LT11 — Manufacture of low-grown leaf at low temperatures — (1968) This experiment was abandoned because of difficulties with sample evalua­ tion. C. Kandappah 1969 Experiments LT12 — Comparison of orthodox manufacture with mixed orthodox Rotorvane— CTC manufacture — (1969) This experiment was started in July and concluded in November. The experiment was conducted in order to determine whether there would be any advantage in producing mixed orthodox-Rotorvane-CTC teas. The treatments investigated were: Treatment 1—Orthodox manufacture (control)—four orthodox dhools were extracted; Treatment 2—One conventional dhool was extracted and the bulk given one Rotorvane and two CTC cuts in series ; Treatment 3—Two conventional dhools were extracted and the bulk given one Rotorvane and two CTC cuts in series; and Treatment 4—One Rotorvane pass and two CTC cuts in series. Withers taken for Treatments 2 to 4 were softer than that taken for treat­ ment 1. The mean percentage moisture contents with the 5% confidence limits were as follows: Treatment Average percentage moisture content 1 59.8 ± 1.5 2 66.3 ± 2.4 3 64.8 ± 2.1 4 65.2 ± 1.8 It was possible to obtain BOP, BOPF and Dust grades from all the treat­ ments. In addition Treatments 1, 2 and 3 yielded two grades of FBOPF and a Pekoe grade. Extraction of an OP grade was possible only from teas of Treatment 1. Samples of the main grades were evaluated by a panel of tasters in Colombo. Results are summarised in Table 1. TABLE 1 — Comparison of orthodox manufacture with mixed orthodox-Rotorvane-CTC manufacture Treatment 1 Treatment 2 Treatment 3 Treatment 4 Grade Grade outturn % Valuation (cents) Grade outturn % Valuation (cents) Grade outturn % Valuation (cents) Grade outturn % Valuation (cents) FBOPF1 3.9 244 2 .0 260 3.5 254 — — FBOPF2 2.1 249 0.9 223 1.5 277 — — BOP 44.5 156 15.3 158 15.4 158 14.2 161 BOPF 19.3 153 39.7 162 39.8 160 43.4 163 Dust 1 Dust 2 4 .21 5.7J 165 1 4 . n 8.4 J 173 13.6T 8.3 J 175 1 8 . 4 | 8 .1J 172 Pekoe 2.1 145 0.6 140 0.7 142 — — OP 6.9 — — — — — — — BM 7.5 — 14.7 — 13.9 — 12.2 — Refuse 2.8 — 4.8 —' 4.7 — 4 .2 — Total main grades 81.8 163 81.0 167 82.8 169 84.1 165 140 ANNUAL REPORT FOR 1969 Analysis of the results indicate that there are no significant differences between any of the treatments for the average nett valuations of the grades evaluated. The sampling covered over 80% of the production and excluded only the OP, BM and refuse teas. C. Kandappah & A. Thevathasan Mid-country experiments (Hantane Station) Experiments MT2 and MT3 have been concluded. General Inadequate facilities for the evaluation of experimental samples have res­ tricted the experimental programme on manufacture at this unit. MT1 — Quality testing of clones — (1966) In view of the difficulties that have arisen in evaluating clonal samples, quality testing of clones was discontinued during the year under review. Clonal manufactures were, however, carried out at Helbodde Estate and Loolecondera Group and samples were evaluated by tasters arranged by the estate concerned. Although the number of manufactures and the method of evaluation were inadequate to classify these clones it would appear that Helbodde clone N 3 could turn out to be a promising clone with regard to quality. Clones D 40, H 13/4 and C/21, also from Helbodde, and LC 2 from Loolecondera also appear to have satisfactory liquoring quality. MT4 — Plucking round-cum-plucked unit — (1967) The aim of this experiment is to determine the effect of plucking rounds of four, six and twelve days durations and that of the plucked unit, which was either a bud and one leaf, a bud and two, or a bud and three leaves, on the liquoring characteristics of the resulting tea. The first stage of the experiment which investigated the effect of these three plucking rounds with leaf of the same plucking standard have been concluded and the results await analysis. The second stage of the experiment which investigates the effect on made tea characteristics of three types of plucking rounds is yet in progress. MT5 — Gramoxone (and hand weeding in combination with 3 levels of nitrogen) on made tea characteristics — (1967) This weed control experiment is now in its second cycle and in the first year after pruning. In this cycle although no yield differences have been observed between the plots receiving the different weed control measures, yield differences between the plots receiving 100 and 200 lb of nitrogen are already significant. Manufacturing tests have been concluded and the results published in the Report of the Technology Division for 1968. MT6 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels and 3 levels of K on made tea characteristics — (1967) Progress in this experiment was also affected by difficulties that have arisen with regard to sample evaluation. ANNUAL REPORT FOR 1969 141 The experimental area was pruned in October and it is hoped to resume test manufactures once the treatments have recovered completely from pruning. MT7 — Age from prune on the characteristics of made tea — (1967) The experimental plots have been divided into three groups, the first and second of which were pruned in 1968 and 1969 respectively. The third group will be pruned in 1970 so that shortly, thereafter, leaf which was found on pretreatment test to be similar in characteristics, could be obtained simul­ taneously from bushes aged 0—12 months, 13—24 months and 25—36 months respectively. Manufacturing tests would begin in 1970, when the third group of plots scheduled to be pruned this year, recover. 1969 Experiments MT8 — Tip content of clones — (1969) This experiment which is based on visual obssrvations is designed to assist in the selection of tip clones. For this purpose a series of standards were made by mixing, in certain proportions, the tip clone W 2/145 with a clone containing a very low tip content, namely TRI 2024. Among the clones studied, the following appear to possess high tip contents: 1. KP204 2. TGK 2 3. W3;and 4. TRI 2045. This experiment is in progress. St Coombs Factory The nett sale average for teas manufactured at St Coombs factory for 1969 was not available at the time of writing. The nett sale average, how­ ever, is likely to be far below that realised in 1968, because of the unsatisfactory valuations realised during the quality season following market trends. An estate staff strike of two months' duration also interfered with the smooth working of the factory, (see Table giving details of crop and manufacturing process). Visits, Lectures and Symposia Dr D. Kirtisinghe, addressed the Hewaheta and Dickoya District Planters' Association on topics related to manufacture. He also attended the annual conference of the United Planters' Association of South India at Koonoor as well as the scientific sessions of the Tea Research Institute in North East India in Tocklai. After these conferences he also visited tea factories in Anamalais and Nilgiris as well as in Assam, Dooars and Darjeeling. Dr Kirtisinghe also served as a member of the Bureau of Ceylon Standards Drafting Sub-Committee on Tea. Month Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Monthly crop G.L. (lb) 169544 127708 68639 183408 248257 129483 126180 120130 124031 140711 126775 136237 Rainfall inches 1.89 2.51 4.20 12.58 12.11 3.27 11.55 10.03 6.01 8.54 11 8 5 22 25 18 18 21 11 20 Crop, Data of Manufacture (Daring the year 1969) Wet Approx. time Period Type of days manufacture of rolling started 1.30 a.m. 12.30 a.m. 10.30 p.m. 2.30 a.m. 7.30 a.m. 4.00 a.m. 3.30 a.m. 4 .00 a.m. 4 .00 a.m. wither (hr) 14* 13* 11* 15* 20* 5.30 a.m. 18* 17 16* 17 17 Mixed Rotorvane Orthodox do do Fermentation hr mt hr mt 2 15 — 2 30 00 — 2 50 — 2 15 00 do 2 15 — 2 30 do 2 30 — 2 45 Records not available Records not available 2 30 — 2 40 Mixed Rotorvane Orthodox ' do do do Orthodox 2 30 — 2 40 2 30 — 2 45 2 30 2 30 Rolling room temp. Highest Lowest Dry Wet Dry Wet 71 68 58 54 69 65 56 50 70 65 56 50 73 69 65 63 75 70 68 65 70 75 64 61 73 68 65 61 74 70 67 63 70 66 62 56 69 65 61 56 Outturn (made tea to green leaf %) 24.98 27.19 28.67 24.64 23.18 21.04 22.94 24.11 24.34 22.98 23.86 23.93 Remarks Power cuts—manufac­ tured before 6.00 a.m. Heavy crop Estate staff on strike — d o - Experiments on com­ mercial scale started Experiments continued Experiments continued Tipping leaf came in Experiments continued Changed over to ortho­ dox manufacture > Z C > r 7> m O 7* H o V O O S V O ANNUAL REPORT FOR 1969 143 Acknowledgements Our thanks are due to several tea tasters in Colombo and to the Agency Houses for their assistance and co-operation in tasting and evaluating our experimental samples. Acknowledgement is also made for the assistance given by Mr A. Theva- thasan in the statistical evaluation of most of the experiments carried out by this Division. Publication KIRTISINGHE, D., MORRIS, P. J. & STRICKLAND-CONSTABLE, R. F . (1968). Retardation of the rate of growth of salol crystals in capillary tubes. J. Crystal Growth 3 & 4, 771-775. REPORT OF THE STATISTICS DIVISION Statistician — P. Kanapathipillai, BSc, FSS General The staff position remained unchanged until tragedy struck towards the end of the year and removed even the one assistant I had. It is with a poignant sense of untimely loss that I have to record the death of Mr K. Seevaratnam. The Statistician continued to act as Chief Administrative Officer in addi­ tion to his duties until 31.4.69. The Statistician also continued to function as Secretary/Convener of the Experimental and Estates Committee. Analyses and Designs Analyses In all about 400 experiments were analysed throughout the year. About 100 of these analyses were done on the ICL Computer at the State Engineering Corporation. The Systems analysts of the Computer Division in collabora­ tion with the Statistician have successfully programmed the following designs. (1) Randomized block with covariance including regression analyses. (2) 3 x 3 factorial in randomized blocks with covariance and regression analyses. (3) 3 x 3 x 3 factorial in blocks of nine plots in a single replicate with covariance. The programme provides for the sums of squares of the main effects to be partitioned into their linear and quadratic components and the interaction sum of squares to be partitioned into their linear x linear components, thus yielding 15 degrees of freedom for the estimation of error. (4) 3 x 3 x 3 factorial in blocks of nine plots each and in more than one replicate with covariance. Provision has also been made in the programme to transform the original data to y/(a + 1) or log (n + 1) where necessary. Designs Coefficients of variation for randomized block designs ranged from 2.8% to 72.5% without covariance adjustment. Even with covariance adjustment the range was as wide as 1.5% to 53.2%. In sharp contrast was the factorial design of the 3 3 or 3 4 type. In these designs, the block size is fixed at nine plots and the coefficient of variation ranged from 4.9% to 7.5%. It does appear that a block size of more than nine plots on the contour is too large in the case of randomized blocks. Perhaps, the existence of "hidden replication" in the case of factorial designs may account for the low coefficients of variation. Whatever the reason, the efficiency of the factorial design has prompted us to lay out even 3 5 designs in l/3rd replicate. Acknowledgements I wish to thank Mr A. N. S. Kulasinghe, Chairman of the State Enginee­ ring Corporation, for having given priority to the preparation of these pro­ grammes, Mr N. S. Amerasinghe, Data Processing Manager, and particularly Mr Percy B. M. Perera, who prepared the programmes. 144 REPORT ON THE LOW-COUNTRY STATION AND THE KOTTAWA SUBSTATION Research Officer — D. T. Wettasinghe, BSc, PhD General The Low-Country Station, St Joachim, Ratnapura Dr. R. L. Wickremasinghe left Ceylon in November for post-doctorate research at the Massachusetts Institute of Technology, USA. He was awarded a Post-Doctoral Research Fellowship by the Federal Government of the United States of America. During his absence, Dr D. T. Wettasinghe was in charge of the Low-Country Station. Dr G. R. Roberts, Research Officer in Biochemistry, was transferred from Talawakele to the Low- Country Station in October. Mr E. J. B. de Silva, Technical Assistant, was appointed Agriculturist, St Joachim Estate in February and is now under­ going training at Albion Estate, Agrapatna. He was replaced by Mr N. L. C. Fernando who was transferred from the Uva Station. Mr W. Joseph, Deve­ lopment Engineer, and Mr N. Yogaratnam, Technical Assistant, left the service of the Institute. Messrs P. B. Ekanayake and K. Vinayagamudali were appointed Technical Assistants. Mr M. Bowatte was appointed Accounts Clerk in March. The Kottawa Substation, Talgampola, Galle District Mr K. H. G. Gunapala remained in charge of the Substation. Mr H. D. Jayasinghe, Technical Assistant, went on transfer and was replaced by Mr S. D. Dharmapala. Advisory Service The Advisory Officer, Mr J. V. Sabanayagam, came into residence at the Low-Country Station from 1st January 1969, and visited estates and addressed planters at their District Associations in the low-country. In addition to his duties in the low-country, he also visited estates in the up-country districts (Dimbula, Dickoya and Nuwara Eliya). Five, three-day refresher courses for Field Officers of the Tea Control Department and Colonization Officers from the Kalutara District Youth Colonization Scheme were arranged at the Low-Country Station, Ratnapura. The Institute's exhibits at the District Agricultural and Industrial Exhi­ bitions held at Avissawella, Matara and Galle, and the Siyawasa Exhibition in Colombo were organised by the Low-Country Station. Replanting tea without reconditioning of the soil has been requested by many estates in the low-country. These areas were inspected and non-eroded land with deep soil, relatively free of boulder and slab rocks was allowed for replanting without reconditioning on an experimental basis. Whereas, the others that are marginal for tea were rejected. In general, low-country estates have reported reduced crop during the year. This may be attributed to the pattern of weather in the last two years.: We have also noted die-back and poor recovery after pruning during the past two seasons in many low-country estates. 145 146 ANNUAL REPORT FOR 1969 Damage by the Low-Country Live Wood Termite, Glyptotermes dilatatus, has been reported from many estates.^ Control measures using fumigation with Phostoxin tablets have been demonstrated to the membership of the Sabaragamuwa and the Southern Province Planters' Associations. The incidence of Red Rust caused by the parasitic alga, Cephaleuros parasiticus, has been on the increase this year. Investigations into the life cycle and the mode of parasitism of this alga are under way. Several cases of stem canker disease described earlier as being caused by the fungus Macrophoma theicola, have been reported from a number of low-country estates, where VP planting has been carried out in marginal areas with gravel and quartz on the surface. Inoculation experiments to establish the identity of the causal organism will be initiated in due course. J. V. Sabanayagam Field Experiments and Trials The following experiments have been concluded :—1 LA3, LA23, LVP6, LPH 2, LPH3, LW14, LW15, LW16, LW18, LW19, LW21, LW27, LW28, XLA2, XLA4, XLA8 and XLPH1. LAI — NPKMg on seedling tea at Endane Estate, Kahawatte — (1955) The yields during the eighth experimental cyele 1967 to 1969 are presented in Table 1. TABLE 1 — Yield over the two-year cycle 1967 to 1969 Treatments (lb per acre per year) 1st year 2nd year First year (lb per acre) (%) Yield Second year (lb per acre) (%) Mean over cycle (lb per acre) (%) 0 0 1301 100 1644 100 1472 100 N 40 80 1415 109 1900 116 1657 113 80 160 1459 112 1965 120 1712 116 0 0 1403 100 1846 100 1624 100 P 2 0 s 30 30 1381 98 1819 99 1600 99 60 60 1390 99 1843 100 1616 100 0 0 1351 100 1807 100 1579 100 KaO 40 40 1419 105 1847 102 1633 103 80 80 1405 104 1854 103 1629 103 0 0 1375 100 1822 100 1598 100 MgO 20 20 1417 103 1852 102 1634 102 40 40 1382 101 1834 101 1608 101 LSD (P - 0.05) 58 4 79 5 66 4 ANNUAL REPORT FOR 1969 147 The response to nitrogen did not extend beyond 40 lb per acre in the first year and 80 lb per acre in the second year. The significant response to 40 lb KjO per acre in the first year was not maintained in the second year of the cycle. There was no response to the phosphate and magnesia fertilizers. This experiment is concluded. A. A. C. Karunaratne LA2 —NKMg and frequency of application on VP tea at Karapincha, Palm- garden Group, Ratnapura — (1961) The yields in the first 18 months of the fourth experimental cycle (1968 to 1971) are presented in Table 2. TABLE 2 — Yield over the first 18 months of the 3-year cycle (1968—1971) Treatments Yield Ob per acre per year) 0b per acre) (%) 75 4211 100 N 150 4371 104 225 4381 104 50 4335 100 K a O 100 4480 103 150 4147 96 0 4124 100 MgO 24 4413 107 48 4426 107 Interval 12 4303 100 (weeks) between 10 4190 97 applications 8 4470 104 LSD (P = 0.05) 308 7 Unlike in the previous cycles the responses to nitrogen and the frequency of application were not significant. Increasing potash from 100 to 150 lb per acre per year significantly depressed yields. For the first time the response to magnesium is significant. Twenty-four pounds MgO per acre per year gave a 7 % increase in yield over the zero level, but increasing MgO to 48 lb per acre per year did not increase yield any further. N. L. C. Fernando LA4 — NPKMg on VP tea at the Kottawa Substation — (1963) The yields obtained in the first year of the second cycle 1968 to 1970 are presented in Table 3. 148 ANNUAL REPORT FOR 1969 Treatments (lb per acre per year) Yield (lb per acre) (%) 75 694 100 N 150 972 140 225 1163 168 0 837 100 P*O s 30 968 116 60 1024 122 0 809 100 K a O 50 981 121 100 1040 129 0 875 100 MgO 30 913 104 60 1041 119 LSD (P = 0.05) 104 12 There was a significant response to nitrogen up to 225 lb per acre per year, phosphate up to 30 lb per acre per year, potash up to 50 lb per acre per year and magnesium up to 60 lb per acre per year. S. D. Dharmapala LAS — Zn, N and frequency of application on seedling tea at the Low-Country Station, Ratnapura — (1963) Over the third two-year cycle the highest yields were obtained with 10 lb zinc sulphate and 125 lb nitrogen per acre per year, but the treatment differen­ ces were not significant. This experiment was terminated. N. L. C Fernando LA7 — Rehabilitation: species and fertilizer at the Low-Country Station, Ratnapura — (1963) - The yields over the first two years of plucking were not significantly different between treatments. This experiment was terminated. LA8 — Rehabilitation with legumes at the Low-Country Station, Ratnapura,^ (1963) The yields over the first 18 months of plucking were not significantly different between treatments. The highest yields were recorded on the Teph- rosia Candida plots. This experiment was terminated. LA9 — Rehabilitation: species, fertilizer and duration at the Low-Country Station, Ratnapura — (1965) TABLE 3 — Yield during the first year of the cycle 1968 to 1970 ANNUAL REPORT FOR 1969 14? The plants were given the second cut at 18 inches in June, tipped in August and brought into plucking in September. There were a large number of casual­ ties in this experiment. The dead plants were affected by stem canker, the cause of which is unknown. The deaths were general and not confined to any particular treatment. P. B. Ekanayake LA10 — Six clones at 3 levels of nitrogen and 3 levels of shade at the Low- Country Station, Ratnapura — (1965) The yield during the second year of plucking is given in Table 4. TABLE 4 — Yield over the second year of plucking Treatments Yield (Clones)H! (lb per acre) (%) TRI 2023 1524 100 TRI 2026 1430 94 TRI 2043 1001 66 MT 18 1176 77 N 3 1018 67 KEN 16/3 1225 80 LSD (P =» 0.05) 129 8 Nitrogen 0b per acre per year) 80 913 100 160 1371 150 240 1403 154 LSD (P = 0.05) 451 49 Unshaded 1223 100 Gliricidia shade (14 ft x 14 ft) 1214 99 Gliricidia shade (7 ft x 7ft) 1251 102 LSD (P = 0.05) 451 37 TRI 2023 and TRI 2026 were significantly superior to the other clones, while TRI 2043 and N 3 were the lowest yielding clones. There was a 50% increase in yield when the nitrogen level was raised from 80 to 160 lb per acre per year. There was no significant difference in yield between the unshaded and shaded plots. LA11 — Bringing into bearing, plucking, pruning, levels of N and duration of cycle in VP tea at the Low-Country Station, Ratnapura — (1965) This experiment was terminated at the end of the first cycle because of vacancies in some plots after pruning. D. D. Kroon LA12 — Three clones, 3 spacings and 3 levels of N at the Kottawa Sub-station -(1961) In the first 30 months of the third experimental cycle 1967 to 1970, TRI 2024 gave the highest yield. Three hundred pounds njtrogen per acre per year was better than 100 or 200 lb. There was no difference in yield between the spacing treatments of 4 ft x 1 f ft, 4 ft x 2 ft and 4 ft x 1\ ft. 150 ANNUAL REPORT FOR 1969 TABLE 5 — Yield over the second year of plucking {Octo­ ber 1968 to October 1969) Treatments Nitrogen Ob per acre per year) 100 200 300 Spacing between rows (ft) 3.5 4 .0 4.5 Spacing within rows (ft) 1.5 2 .0 2.5 LSD (P = 0.05) Yield (lb per acre) (%) 1200 100 1381 115 1475 123 1352 100 1381 102 1325 98 1378 100 1279 93 1419 103 127 10 There was a significant yield increase of 15% when the nitrogen level was increased from 100 to 200 lb per acre per year. There were no differences in yield between the spacing treatments. D. D . Krooa LA16 — NPKMg and frequency of application on VP tea at Hunuwella Group, Opanaike — (1965) The yields during the first year of the cycle 1968 to 1970 are presented ia Table 6. LA13 — Three clones, 3 spacings and 3 levels of nitrogen at the Kottawa Sub­ station — (1962) In the first 18 months of the third experimental cycle 1968 to 1971, thero was no significant difference in yield between the three clones, TRI 2023, 18B and TRI 2026, or between the three spacings, 4 ft x 14 in., 4 ft x 28 in. and 4 ft x 42 in. Three hundred pounds nitrogen per acre per year gave the highest yield. S. D . Dharmapala LAM — Spacing and fertilizer on VP tea at the Low-Country Station, Ratna­ pura — (1965) The yields obtained during the second year of plucking are presented in Table 5. ANNUAL REPORT FOR 1969 151 Treatments Yield Ob per acre per year) Ob per acre) (%) 120 3175 100 N 240 3404 107 360 3308 104 0 3355 100 P2O5 30 3295 98 60 3236 96 0 3335 100 K a O 60 3292 99 120 3259 98 0 3391 100 MgO 25 3245 96 50 3250 96 Interval 6 3409 100 (weeks) 8 3336 98 between appli­ cations 10 3142 92 LSD (P = 0.05) 174 5 There was a significant response to nitrogen up to 240 lb per acre per year. Intervals of six and eight weeks between fertilizer applications were significantly better than 10 weeks. There was no response to phosphate, potash or magnesium treatments. A. A. C. Karunaratne LA17 — Types and levels of nitrogen, levels of dolomite on seedling tea at the Low-Country Station, Ratnapura — (1965) 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 year, This experiment was terminated. H. H. Samarakoon LA18 — Rehabilitation with legumes at the Low-Country Station, Ratnapura— (1966) The plants were given the second cut at 18 inches in June, tipped in August and brought into plucking in September. Here too, the plants were affected by stem canker as in the adjoining Experiment LA9. The number of plants affected was small. The weights of cuttings from the second cut at 18 inches were not signi­ ficantly different between treatments. P. B. Ekanayake LA19 — Clones, bringing into bearing, plucking, pruning and duration of cycle in VP tea at the Kottawa Substation — (1966) This experiment was severely affected by the prolonged drought experienced shortly after the tea was brought into plucking. The drought effects have resulted in considerable variation within blocks. The introduction of further treatments would therefore be delayed until the next cycle. S. D.Dharmapala TABLE 6 — Yield over the first year of the cycle (1968 to 1970) 152 ANNUAL REPORT FOR 1969 TABLE 7 — Yield (lb per acre per year) over the first two-and- a-half-year cycle (1967 to 1969) Treatments Yield (lb per acre per year) (lb per acre) (%) N 240 5372 100 360 5389 100 480 5358 100 P 2 O 5 0 5301 100 30 5408 102 60 5411 102 K 2 0 0 5398 100 60 5341 99 120 5382 100 Intervals in 8 5394 100 weeks between 6 5325 99 applications 4 5400 100 LSD (P = 0 . 0 5 ) 98 2 There was no response to nitrogen beyond 240 lb per acre. Phosphate at 30 lb P 2O s per acre increased yields significantly. There was no response to potash, and to fertilizer applied more frequently than eight weeks. The nitrogen and the frequency of application treatments were altered at the end of the first cycle and the following levels are being tested in the second three-year cycle (1969 to 1972): 120, 240 and 360 lb N per acre per year, and fertilizer applications at 12, 10 and eight weeks intervals. LA21 — NPKMg and frequency of application on VP tea at Kobomella Group, Beralapantara — (1966) The mean yields during the first two-and-a-half-year cycle 1967 to 1969 are given in Table 8. TABLE 8 — Yield (lb made tea per acre per year) over the first two-and-a-half-year cycle (1967 to 1969) Treatments Yield (lb per acre per year) (lb per acre) (%) 240 5195 100 N 360 5422 104 480 5465 100 P*O s 0 5411 100 30 5324 98 60 5335 99 K 2 0 0 5357 100 60 5411 101 120 5314 9 9 0 5357 100 MgO 25 5346 100 50 5378 100 Intervals 8 5411 100 (weeks) between 6 5378 99 applications 4 5292 98 LSD (P = 0 . 0 5 ) 189 4 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 fertilizer application treatments. LA20 — NPKMg and frequency of application on VP tea at Ratnayake Group, Deniyaya — (1966) The mean yields during the first two-and-a-half-year cycle 1967 to 1969 are presented in Table 7. ANNUAL REPORT FOR, 1969 153 TABLE 9 — Yield during the first year of the cycle (1968 to 1971) Treatments Yield 0b per acre) (7.) N Ob/acre/year) 160 4898 100 320 5034 103 480 5305 108 Intervals in 8 5111 100 weeks between 6 5150 101 applications 4 4995 98 Sulphate of ammonia. 4995 100 Urea 5150 103 Calcium ammonium nitrate 5111 102 Dolomite (ton/acre/year) 0 5111 100 i 4995 98 1 5150 101 LSD (P = 0.05) 269 4 There was a yield response up to 480 lb nitrogen per acre per year. The differences in yield between the forms of nitrogen, dolomite levels and the frequency of application treatments were not significant. LA26—: Methods of pruning, frequency of plucking and duration of cycle on VP tea at Handford Estate, Deniyaya — (1966) The yields obtained over the two-year cycle 1967 to 1969 are presented in Table 10. The nitrogen and the frequency of application treatments were altered at the end of the first cycle, and the following levels are being tested in the second three-year cycle (1969 to 1972): 120, 240 and 360 lb N per acre per year, and fertilizer applications at 12, 10 and eight weeks intervals. LA22 — NPKMg and frequency of application on seedling tea at Anningkande Estate, Deniyaya (1966) The yields obtained during the first two-ahd-a-half-year cycle (1967 to 1969) were not significantly different between treatments. However, during the first 18 months of the cycle there was a significant response up to 60 lb KjO per acre. LA24 — Three 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) There were no significant differences in yield between treatments over the first year of the second cycle 1968 to 1971. LA25 — Three 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 Enselwatte Group, Deniyaya — (1966) This experiment was pruned in September 1968. The yields obtained in the first year of the second cycle 1968 to 1971 are recorded in Table 9. 154 ANNUAL REPORT FOR 1969 Yield Treatments (lb per acre) (%) Frequency of 4 3712 100 plucking 5 3258 87 (days) 6 3146 84 Method of pruning-Rim-lung 3358 100 Centre-lung 3365 100 Cut-across 3392 101 LSD (P = 0.05) 58 2 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. This experiment was terminated. LA27 — Methods of pruning, frequency of plucking and duration of cycle on seedling tea at Anningkande Estate, Deniyaya — (1966) The yields obtained in the two and a half years, April 1967 to October 1969, are presented in Table 11. TABLE 11 — Yield over the two-and-a-half-year period, April 1967 to October 1969 Treatments Frequency of 5 plucking 6 (days) 7 Method o f pruning-Rim-lung Centre-lung Cut-across Length of pruning cycle (years) 2 2 * 3 LSD (P = 0.05) Yield (lb per acre) (%) 8397 100 7599 90 7212 86 7744 100 7768 100 7720 100 7357 100 7913 108 7962 108 163 2 Plucking every five days gave a higher yield than plucking every six days. Plucking every seven days gave the lowest yield. There was no difference in yield between the methods of pruning. J. I. H. Bandaranayake LA28 — NPK, types of N and levels of lime on VP tea at Hapugastenne Group, Ratnapura — (1966) This experiment was pruned in July 1969. The results will be presented at the end of the first year of the second cycle (1969 to 1972) LA29 — NPK and frequency of application on seedling tea at Sapumalkande Group, Dehiowita — (1966) This experiment was pruned in June 1969, and the results will be presented at the end of the first year of the second cycle 1969 to 1972. TABLE 10 — Yield (lb per acre per year) over the two-year cycle (1967 to 1969) ANNUAL REPORT FOR 1969 155 Yield : - Treatments 0b per acre) (%) Sulphate of ammonia 4855 100 • CAN 4488 92 Urea 4597 95 N 0b per acre per year) 240 4502 100 . 360 4706 104 480 4733 105 Intervals 8 4556 •.... 100 (weeks) between 6 4692 103 applications 4 4678 103 Dolomite (tons per acre per year) 0 4692 100 J 4624 98 1 4624 98 LSD (i» = 0.05) 150 4 Sulphate of ammonia gave significantly higher yields than calcium am­ monium nitrate and urea. The response to nitrogen extends up to 360 lb per acre per year. The nitrogen and the frequency of application treatments were altered at the end of the first cycle and the following levels are being tested in the second three-year cycle (1969 to 1972) : 150,300 and 450 lb N per acre per year, and fertilizer applications at 12,10 and eight weeks intervals. LA32 — Three 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 Talgaswela Estate, Talgaswela—(1966) The yields obtained during the first two-year cycle 1967 to 1969 were not significantly different between treatments. S. D. Dharmapala LA33 — NPKMg and frequency of application on VP tea at Nil-Ella Estate, Morawaka—(1967) There were no significant differences in yield between treatments over the first two-year cycle, 1967 to 1969. The nitrogen and the frequency of application treatments were altered at the end of the first cycle and the following levels are being tested in the second three-year cycle (1969 to 1972) : 120, 240 and 360 lb N per acre per year, and fertilizer applications at 12, 10 and eight weeks intervals. J. I. H. Bandaranayake • The nitrogen and the frequency of application treatments were altered at the end of the first cycle. In the second three-year cycle (1969 to 1972), 80, 160 and 240.1b N per acre in the first year and 120,240 and 360 lb N per acre per year in the second and third years of the cycle are being tested. The intervals between fertilizer; applications would be 12, 10 and eight weeks. 1 N. L. C. Fernando LA31 Three types of N (urea, calcium ammonium nitrate and sulphate of ammonia), 3 levels of N, 3 frequencies of application and 3 levels ... ofdolomite on VP'tea'.at Talangaha Estate, Nakiyadeniya — (1966) The yields obtained over the first two-year cycle 1967 to 1969 are pre­ sented in Table 12. TABLE 12 — Yield (lb per acre per year) over the two-year cycle (1967 to 1969) 156 ANNUAL REPORT FOR 1969 LA34 — NPKMg on VP tea at the Low-Country Station, Ratnapura—{1967) The tea was brought into plucking in January 1969. The yields recorded during the first six months of plucking do not show significant differences between treatments. Although some plots have hot received any P 8O s, KjO or MgO from the time of planting, visual symptoms of deficiency of these nutrients are not evident. P. B. Ekanayake LA35 — Levels of nitrogen, phosphorus, potassium and magnesium on young plants of TRI 2025 in pots at the Low-Country Station, Ratnapura—4 randomized blocks—{1968) The tea plants failed to establish satisfactorily in the pots. The experi­ ment is now being repeated with plants of clone TRI 2025. N. S. Rajendran LA36 — Three levels of nitrogen on 4 clones at the Low-Country Station, Rat­ napura—(1968) The plants were given the first cut at 12 inches in July and the second cut at 16 inches in December. The tea will be brought into plucking next year. The 1968 report erroneously stated that three nitrogen levels are being tested. All plots receive T200 mixture at an uniform rate. Nitrogen levels will be introduced after the first prune. D. D. Kroon 1969 Experiments * LA37 — Inter-row crops in young tea—3 randomized blocks—(1969) In this experiment Tephrosia Candida, Tephrosia vogelli, Styldsanthes gracilis, Desmodium ovalifolium, Cymbopogon confertiflorus and Paspalum dilatatum and the natural weed species are being tested as inter-row species. The growth of the tea in these plots will be compared with that in plots kept bare, and thatched with Guatemala grass. Tea (TRI 2023) was planted in June, one month after the inter-row crops were planted. The growth of the tea was assessed in December, and it was evident that Stylosanthes gracilis and Cymbopogon confertiflorus have appreciably retarded the growth of tea. P. B. Ekanayake LA38 — Diversification of tea land—Observation plots of timber species—(1969) Four varieties are being tried out. Eucalyptus saligna and Eucalyptus camuldulensis were planted at a spacing of 10 ft x 10 ft and Pinus caribea at 8 ft x 8 ft in standing tea. Dendrocalamus strictus, a bamboo, was planted at 10 ft x 10 ft spacing in cleared tea land found to be unsuitable for replanting with tea on account of being rocky. All varieties were planted in December. K. Vinayagamudali Clonal selection and testing LVP1 to LVP5 '— 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. S. D. Dharmapala ANNUAL REPORT FOR 1969 157 LVP7 — Clonal selection at the Low-Country Station, Ratnapura—(1965) Selections from St Joachim Of the 220 St Joachim selections, 42 have been selected for further testing. Selections from Lansdowne TRI 2023 x TRI 2026, and Endane Seedlings These selections have now been in plucking for a year. None of these selections shows promise. D. D. Kroon LVP8 — Clonal selection at the Kottawa Substation—{1966) Four of the 11 selections appear promising and will be taken for further testing. K. H. G. Gunapala LVP9 — Clonal selection for drought resistance at Rye Estate, Balangoda— (1966) The rains during the 1968 planting season failed resulting in a large number of casualties in the experimental plots. None of the selections established satisfactorily under these conditions. Further testing of these clones will be carried out at the Agratenne Substation. D. D. Kroon 1969 Experiment LVP11 — Clonal testing at the Low-Country Station, Ratnapura — 5 x 6 rec­ tangular lattice — (1969) In this experiment the following clones are being compared: TRI 2021, 2022, 2023, 2024, 2025, 2026, 2027, 2043, 2045, 2151, CW 21, PCG 2, PUH 5, NK 4B 29, MT 18, DG 39, DG 7, H 1/58, H 13/4, M 20, MPA 1, KEN 16/3, GMT 9, S 106 and W/2-145. These clones were considered as the most promising for growing at low elevations on the basis of the yield results available from clonal experiments carried out since 1961. The clones were planted in June and the first bending done in August. D. D. Kroon Pruning experiments LPH4 — Duration of lung retention on recovery from pruning and on yield in seedling tea at the Low-Country Station, Ratnapura — (1967) Over the two-year cycle 1967 to 1969 the highest yield was obtained where lungs were removed eight weeks after pruning. This was significantly greater than when lungs were removed after four weeks. This experiment is terminated. LPH5 — Plucking the lungs on recovery from pruning and yield of seedling tea at the Low-Country Station, Ratnapura — (1968) There were no significant differences in yield between treatments over the first 18 months after pruning. This experiment is terminated. N. S. Rajendran TABLE 13 — Schedule of operations and weed growth assessments in LW 23 Treatments % Weed cover 25-2-69 Diuron applied on 1-3-69 Ob/acre) % Weed cover 12-5-69 Diuron applied on 13-5-69 Ob/acre) % Weed cover lfc-7-69 Diuron applied on 18-7-69 (lb/acre); %Weed cover 8-9-69 Diuron applied on 21-9-69 % Weed cover 2-12-69 1 39 0.5 39 0 .5 66 0.5 30 0 .5 56 2 21 1 0 19 — 50 1.0 17 — 3 25 1.5 15 ' — 38 1.5 9 •— 26 4 38 2 .0 14 — r . 41 2 .0 11 27 ANNUAL REPORT FOR 1969 159 Evaluation of herbicides LW13 — Simazine, diuron, 2, 4-D and amitrole on the yields of seedling tea — (1967) The treatments have now been applied on 12 occasions. Therefore, at the higher level of treatment, the plots have received a total of 19.2 lb diuron, or 19.2 lb 2,4-D, or 24 lb simazine, or 24 lb amitrole per acre within a period, of two years. These treatments did not affect the yield of tea. LW20 — Simazine, diuron, fluometuron and pentachlorophenol on the growth of young tea (Clone TRI 2023) — (1968) This experiment was abandoned as some plots were damaged by the run­ off from a breached storm-drain. H. H. Samarakoon LW22 — Evaluation of herbicides — (1968) Lenacil, linuron and diuron displayed extreme herbicidal activity over a wide range of species including the paraquat-resistant species Paspalum con­ jugation and Borreria spp. CP 44939, fluometuron, atrazine, desmetryne and neburon were effective against Borreria spp., but not effective against Paspalum conjugation. Atratone, chloroxuron and prometryne gave good control of Paspalum conjugatuni but did hot control Borreria spp. effectively. Propa- chlor was ineffective against both Paspalum conjugation and Borreria spp! but gave good control of Cyperus temticulmis. All chemicals tested, effectively controlled Cleome burmanii, Ageratum conyzoides and Bulbostylis puberula. 1969 Experiments LW29 — Foliar activity of some soil-acting herbicides — 5 randomized blocks — (1969) The following herbicides were screened for their foliar activity: diuron, linuron, fluometuron and lenacil, all at the rate of 1.2 lb a.i. per acre; des­ metryne, atrazine, atratone and prometryne, at 1.0 lb a.i. per acre. All chemicals were applied in a volume of 75 gallons water per acre containing 0.5% of a wetting agent. Fluometuron was used with CIBA wetting agent, while all other herbicides were used with surfactant 'N' (octyl phenol/ethylene oxide condensate). The predominant weed species in the experimental plots were Borreria hispida, Cleome burmanii, Vemonia cineria, Cyperus spp, and Digitaria spp. The performance of these chemicals was assessed by visual rating. Diuron was the only herbicide which was effective through the foliage and gave about 60% kill, 10 days after application. The other chemicals had negligible effect. Weed control LW23 — Diuron for weed control in mature tea—(1968) • < A schedule of operations and weed growth assessments are given in Table 13. 160 ANNUAL REPORT FOR 1969 Two applications of diuron at 1.0 lb per acre was sufficient to maintain weed control, and was more effective as well as economical than four applications of diuron at 0.5 lb per acre. Rates higher than 1.0 lb per acre are not warranted, LW24 — Diuron for weed control in shaded and unshaded mature tea—(1968) This experiment which was similar to LW 23 had to be abandoned due to a mishap. LW25 — Control o/Paspalum conjugatum—(1968) The effect of the treatments was assessed periodically by visual rating. The addition of surfactant 'N' (octyl phenol/ethylene oxide condensate) at the rate of f pint to 50 gallons spray solution considerably improved the efficacy of Gramoxone and diuron mixture. Half pint Gramoxone + 0.6 lb diuron + f pint surfactant 'N' in 50 gallons water per acre was the most effective treat­ ment and gave about 65 % control four months after applications. 1969 Experiments LW30 — Timing of application of diuron—Large-scale observation plots—(1969) The first application of diuron in the year is generally given in March or April at the beginning of the wet season. However, it was observed that the timing of this application in relation to both the onset of the rains and the growth of the weeds was important. In this trial, the first application of 0.8 lb diuron + £ pint surfactant 'N' in 50 gallons water per acre was given in either mid-March or late March or mid-April or late April. Each plot received a second application in June. The weed growth was assessed in October. The results are presented in Table 14. TABLE 14 — A schedule of operations and weed growth assessments in LW30 First application Rain since break Second Stage of in drought application % Weed cover atment Date weed growth Inches Wet days Date 5-10-69 1 17-3-69 Very small 5.6 6 3-6-69 29 2 - 31-3-69 2—4 leaves , 7.6 11 3-6-69 36 3 15-4-69 4—6 leaves 15.9 24 15-6-69 38 4 30-4-69 6—10 leaves . 24.3 36 29-6-69 75 The most suitable time for applying diuron appears to be soon after the first rains of the wet season, when the weed seeds are germinating. When the application is delayed, the larger weeds are only partially controlled. The weeds which escape the first application become mature, and are quite resistant when the second application is given. N. S. Rajendran Weed competition LW 5 — Weed effects on crop and yield of seedling tea at the Low-Country Station, Ratnapura—{1965) ANNUAL REPORT FOR 1969 161 Weed removal by hand every two months gave the highest yields and this treatment was significantly superior to weed removal every four and every six months. The Gramoxone treatment did not control weeds adequately and gave lower yields than hand weeding every two months ; the difference ho.wever did not reach the level of significance. Nitrogen at 200 lb per acre per year gave significantly better yield than 100 lb per acre per year. The results are given in Table 15. This experiment is concluded. TABLE 15 — Yield (lb per acre per year) over the two-year cycle (1967 to 1969) Treatments Yield N levels 100 200 flb per acre) Mean Weeds removed every 2 months 1554 1660 1607 Weeds removed every 4 months 1257 1581 1419 Weeds removed every 6 months 1310 1408 1359 Gramoxone i pint per acre bimonthly 1530 1467 1498 LSD (P = 0.05) 220 156 Mean 1412 1529 LSD (P = 0.05) 110 1969 Experiments LW31 — Effect of different systems of weeding on growth of young tea—5 ran­ domized blocks (1969) In this experiment four systems of strip-weeding are being tested in one- year-old tea (TRI 2026) planted at a spacing of 4 ft between rows and 2 ft in the row. Weeds are removed by hand monthly except in :— (1) 1 ft wide strip between tea rows (2) 2 ft wide strip between tea rows (3) 1 ft wide strip in the tea row, and (4) 2 ft wide strip in the tea row. Clean-weeded and unweeded plots are also included for comparison. LW32 — Effect of frequency of weeding'on yield of VP tea—4 randomized blocks—(1969) Four-year-old tea (TRI 2023) was pruned in May and all plots weeded in July and the following treatments introduced :— (1) Manual weeding every 2 months (2) Manual weeding every 4 months (3) Manual weeding every 6 months, and (4) Paraquat (0.125 lb per acre) every 2 months. Each treatment is combined with two levels of nitrogen, viz 150 and 300 lb per acre per year. At each weeding the weeds are returned to the plots. 162 ANNUAL REPORT FOR 1969 TABLE 16 — Yield during the first year of the cycle (1968 to 1970) Treatments Nitrogen Yield 0b per acre per year)' 0b per acre) (%) 0 3167 100 120 3599 114 240 4111 130 360 4218 133 LSD (P = 0.05) 416 13 No shade 3842 104 Shade 3706 100 LSD (P = 0.05) 1155 31 The response to nitrogen extends up to 240 lb per acre per year. The difference in yield between shaded and unshaded plots is not significant. LW33 — Effect of frequency of weeding on yield of VP tea—4 randomized blocks—{1969) This experiment is a repetition of LW 32, except that the weeds are removed from the plots. Weed biology LW17 — Seasonal pattern of weed emergence under mature seedling tea—(1967) Weed counts were maintained over a period of two years. The data have not been fully analysed as yet, but a preliminary examination indicates that the pattern of weed emergence closely resembles the rainfall distribution. This experiment is terminated. A. A. C. Karunaratne LW26 — Herbarium of weeds—(1968) Twenty one species have been prepared and identified. A further 23 specimens have been collected, prepared and sent for identification. N. S. Rajendran Extension Experiments XLA1 — Three types and 3 levels of N (urea, calcium ammonium nitrate, sulphate of ammonia) and 3 levels of lime on VP tea at Hunuwella Group, Opanaike — (1965) The yields recorded in the first year of the second two-year cycle 1968 to 1970 did not show significant differences between the types of nitrogen fertilizer, or the levels of nitrogen (240, 360 and 480 lb per acre per year), or the levels of dolomitic lime (0, \ and 1 ton per acre per year). XLA3 — Four levels of nitrogen x 2 levels of shade on VP tea at Hunuwella Group, Opanaike — (1965) The results of the first year of the second two-year cycle 1968 to 1970 are presented in Table 16. ANNUAL REPORT FOR 1969 163 XLA5 — Three types of N (urea, calcium ammonium nitrate and sulphate of ammonia), arid 2 levels of lime on VP tea at Endane Estate, Kaha- watte — (1965) The results of the first year of the second two-year cycle 1968 to 1970 are presented in Table 17. TABLE 17 — Yield during the first year of the cycle (1968 to 1970) Treatments Yield (lb per acre) (%) Sulphate of ammonia 3718 100 Calcium ammonium nitrate 3965 107 Urea 3582 96 LSD (P = 0.05) 220 6 Dolomite (cwt per acre per year) 0 10 3802 3702 100 97 LSD (/> = 0.05) 180 5 Calcium ammonium nitrate was superior to both sulphate of ammonia and urea. Application of dolomite has not increased yields. XLA6 — Five levels of nitrogen on VP tea at Endane Estate, Kahawatte — (1965) The results of the first year of the second two-year cycle 1968 to 1970 are presented in Table 18. TABLE 18 — Yield in the first year of the second cycle (1968 to 1970) Treatments Y i e l d Nitrogen First 6 months Second 6 months First year (Ib/acre/year) (lb/acre) (%)' (lb/acre) (%) (lb/acre) (%) 0 1070 100 2396 100 3465 100 120 1079 101 2502 104 3582 103 240 1094 102 2812 117 3906 113 360 1128 105 2933 122 4061 117 480 1137 106 2599 108 3736 108 LSD (P = 0.05) 192 18 362 15 503 15 In the first six months of the cycle there was no significant response to nitrogen, but in the second six months there was a significant response up to 240 lb N per acre per year. XLA7 — Four levels of nitrogen x 2 levels of shade on seedling tea at Rayigam Estate, Ingiriya — (1965) The results of the cycle 1967 to 1969 are presented in Table 19. 164 ANNUAL REPORT FOR: 1969 Treatments Y i e l d Nitrogen 2nd year Mean of cycle (lb/acre/year) (lb/acre) • (%) (lb/acre) (%) 80 1836 100 1511 100 120 1791 98 1484 98 160 1901 104 1568 104 200 1878 102 1543 102 LSD (P = 0.05) 204 11 169 11 Shade 1542 100 1281 100 No shade 2161 140 1771 138 LSD (P = 0.05) 392 25 251 20 The yield of the unshaded plots was significantly greater than that of the shaded plots. There was no response to nitrogen applications above 80 lb per acre per year. XLA9 — Four levels of nitrogen x 2 levels of shade on VP tea at Millakande Estate, Bulathsinhala — (1965) The results of the first year of the second cycle 1968 to 1970 are presented in Table 20. TABLE 20 — Yield during the first year of the cycle (1968 to 1970) Treatments . Y i e l d Nitrogen First 6 months Second 6 months First year (lb/acre/year) (lb/acre) . (%) (lb/acre) . (%)• (lb/acre) (%) 0 830 100 2373 100 3203 100 160 767 92 2592 109 3360 105 320 804 97 2830 119. 3634 113 480 815 98 - 2635 I l l 3452 108 LSD (P = 0.05) 114 14 367 15 428 13 Shade 804 100 2583 100 3387 100 No shade 804 100 2632 102 3438 102 LSD (P = 0.05) 369 44 766 30 1053 31 There was no response to nitrogen during the first six months of the cycle. During the second six months of the cycle there was a significant res­ ponse up to 320 lb N per acre per year. The difference in yield between shaded and unshaded plots was not significant. A. A. C. Karunaratne XLA10—Types of N (calcium ammonium nitrate, sulphate of ammonia and urea) on VP tea at Wellandura Estate, Kahawatte — (1966) There were no significant differences in yield between treatments over the two year cycle 1967 to 1969. This experiment was terminated. XLA11 — Four levels of nitrogen x 2 frequencies of application on 6 clones at Balangoda Group, Bogawantalawa— (1966) The results of the 12-month period, August 1968 to August 1969, are presented in Table 21. TABLE 19 — Yield (lb per acre per year) over the cycle . . . . . . (1967 to 1969) ANNUAL REPORT FOR 1969 165 TABLE 21 — Yield (lb per acre) during the 12-month period from the 30th to 42nd month of cycle (1966 to 1970) Levels of nitrogen (lb) 480 Mean Clones 120 240 360 (Clones) (%) MT 18 1608 2243 3100 3416 2592 100 MT 16 1942 2621 2904 2817 2571 99 DG 39 1782 2868 2882 2770 2575 99 TRI 2025 2254 2668 3216 4062 3050 117 TRI 2023 2389 3271 3525 3347 3133 121 TRI 2024 2374 2712 2889 3140 2779 107 LSD (P = 0.05) 358 14 Means (N levels)' 2058 2730 3086 3259 % 100 133 150 158 LSD (P = 0.05) Between mean N levels 359 Between % 17 The TRI clones 2023 and 2025 were superior to 2024 and the Balangoda clones. TRI 2025 and MT 18 showed an appreciable yield response when the nitrogen level was raised from 360 to 480 lb per acre per year, whereas TRI 2023, MT 16 and DG 39 gave the highest yield at 360 lb N per acre per year. XLA12 — Four levels of nitrogen x 2 levels of shade on seedling tea at Sapu- malkande Group, Dehiowita — (1966) In this experiment; over the two-and-a-half-year cycle (1966 to 1969) the mean yield was 2531 lb per acre per year. There was no significant difference in yield between the shaded and unshaded plots, and the four levels of nitrogen, 80, 160, 240 and 320 lb per acre per year. N. L. C. Fernando XLA13 — Four levels of nitrogen on TRI clones 2024, 2025 and 2026 at Beru- beula Estate, Urubokka — (1966) The yields recorded during the two-year cycle 1967 to 1969 did not show significant differences between the three clones, TRI 2024, TRI 2025 and TRI 2026. The application of nitrogen did not increase yields. XLA14 — Four levels of nitrogen x 2 levels of shade on VP tea at Ratnayake Group, Deniyaya — (1966) This experiment was pruned in June 1968. The yields recorded in the first 18 months of the second cycle 1968 to 1971 are presented in Table 22. TABLE 22 — Yield during the first 18 months of the cycle (1968 to 1971) Yield Treatments (lb per acre) (%) No shade 7790 100 Gliricidia maculata 7487 96 LSD (P = 0.05) 3847 49 Nitrogen 0b per acre per year) 0 6466 100 160 7909 122 320 8121 126 480 8059 125 LSD (P = 0.05) 301 5 166 ANNUAL REPORT FOR 1969 Yield (lb per acre) (%) 4275 100 4928 115 5391 126 5446 127 405 9 5200 100 4819 92 1354 26 The response to nitrogen extends up to 160 lb per acre per year. There is no difference in yield between the shaded and unshaded plots. XLA15 — Four levels of nitrogen x 4 levels of shade on seedling tea at Panil- kande Estate, Deniyaya — (1966) This experiment was pruned in August 1968. The yields recorded in the first year of the second cycle 1968 to 1970 were not significantly different between treatments. XLA16 — Four levels of nitrogen x 2 levels of shade on VP tea at Mahendra Estate, Morawaka — (1966) This experiment was terminated at the request of the Superintendent. XLA17 — Four levels of nitrogen x 2 levels of shade on VP tea at Berubeula Estate, Urubokka — (1966) The yields during the first 18 months of the three-year cycle 1968 to 1971 are presented in Table 23. TABLE 23 — Yield (lb per acre) over the first 18 months of the cycle (1968 to 1971) Treatments Nitrogen (lb/acre/year) 0 160 320 480 LSD (P = 0.05) No shade Shade LSD (P - 0.05) The response to nitrogen extends up to 320 lb per acre per year. There is no difference in yield between shade and no shade treatments. J. I. H. Bandaranayake XLA18 — Three types of nitrogen (urea, calcium ammonium nitrate and sul­ phate of ammonia), and 3 levels of nitrogen on TRI 2023 at Tal- gaswella Estate, Talgaswela — (1968) The yields obtained during the first 18 months of the cycle (1968 to 1970) do not show significant differences between treatments. S. D. Dharmapala Visits, Lectures & Symposia Visit Dr D. T. Wettasinghe represented the Tea Research Institute at the con­ ference of the United Planters' Association of Southern India held at Coonoor in September. He also visited several tea estates and factories in various districts to study cultural practices there. ANNUAL REPORT FOR 1969 167 Lecture WETTASINGHE, D. T. — "Use of herbicides in tea cultivation" to the Kandy District Planters' Association at Kandy in November. Publications FERNANDO, L. H . BANDARANAYAKE, J. I. H. & YOGARATNAM, N. (1969). Fertilizer responses in low-grown clonal tea. Tea Q. 40, 53-59. FERNANDO, L. H., BHAVANANDAN, V. P., WETTASINGHE, D. T. & MANIPURA, W. B. (1969). Fertilizer recommendations for tea in Ceylon — 1969. Tea Q. 40, 129-134. WETTASINGHE, D. T. & RAJENDRAM, N. S. (1969). Evaluation of herbicides for weed control in tea. 1—Preliminary screening trials. Tea Q. 40, 160-163. REPORT ON THE MID-COUNTRY STATION Advisory Officer — M. K. Vythilingam General Dr D. Calnaido was awarded a Senior Research Fellowship by the Alex­ ander Von Humboldt Foundation of West Germany and left Ceylon in July, to work at the "Institute of Plant Diseases", University of Bonn for a year. Dr D. Calnaido served for a short period, as the President of Section B (Agri­ culture and Forestry) of the Ceylon Association for the Advancement of Science, prior to his departure on study leave abroad. He was also a visiting lecturer at the Department of Zoology, University of Ceylon, Peradeniya. Mr M. K. Vythilingam was responsible for the Mid-Country Station during the absence of Dr. Calnaido during his period of overseas leave. Mr V. Kodagoda was transferred to the Mid-Country Station on 8th June to take over the duties of Clerk-Typist. The approach road to the Station, leading to the laboratory, bungalows and stores, was metalled and tarred in August/September. Diversification of Crops One acre of each of the following species was planted on an experimental basis in Field No. 6 in December. 1. Eucalyptus saligna 2. Eucalyptus camuldulensis 3. Pinus caribea 4. Dendrocalamus sp. Advisory Service The Mid-Country Scientific Officer and/or the District Advisory Officer attended the District Planters' Association meetings, when invited. Many planters visited the Station for discussions on agronomic problems. Several groups of school children visited the Station on study tours. Large numbers of tourists also visited the Station to learn about tea. One hundred and ten visits were made to estates in connection with advisory and extension work. The Director, the Mid-Country Scientific Officer, the Technologist, the Agricultural Chemist and the Low-Country Agronomist, addressed the Planters' Association of Kandy, Hewaheta and Pussellawa on manuring, insect pests, tea manufacture and weed control. Pests and diseases Sporadic infestations of thrips, cockchafer grubs, brown bugs, bag worms, scales, Looper and Lobster Caterpillars were encountered in the mid-country districts. Tortrix attack was fairly severe in the Pussellawa District in spite of a very small acreage being treated with heptachlor. The problem of Shot- hole Borer in new clearings was also relatively serious as many estates did not spray their clearings with heptachlor. The diseases encountered were only Poria and Ustulina which were not serious problems. 168 ANNUAL REPORT FOR 1969 169 New clearings The weather conditions were favourable in most districts, except in the Kandy area where some new clearings suffered during the February/March drought. Many mid-country estates have resorted to replanting. Nursery The percentage of success in most estate nurseries was very high this year due to better standard of nursery management. Fertilizer With the decline in the sale prices of tea in the early part of the year, many estates either reduced fertilizer or completely stopped fertilizing due to the losses incurred. However, when the prices showed improvement in the latter part of the year, estates resumed their usual fertilizer programme. Field Experiments, Trials and Factory Experiments The following experiments were carried out with the collaboration of the respective Heads of Division, except in the experiments on Entomology. Details of these experiments are given in the respective divisional reports. Weed Research Experiment MW2 was concluded in 1968 (see Annual Report for 1968, Part 2). MW1 — Gramoxone, hand-weeding and nitrogen on seedling tea —- (1966) The plots were pruned in October 1968 and brought into plucking in March 1969. There was a significant difference in yield between the 100 and 200 lb nitrogen levels but there were no significant differences between the weed control treatments. The calculated yields per acre per year are as follows : N level Hand weeding (lb/acre/year) 100 1324 200 1535 LSD (P < 0.05) = 210 MW3 — The effect of amitrole, dalapon, diuron, linuron, fluometuron, atrazine and lenacil, on yield of seedling tea — 3 randomized blocks — (1968) Pre-treatment pluckings were done up to 6.10.69. The treatments were given on 12.10.69. Amitrole at 1 and 2 lb per acre caused chlorosis of the leaves, a fortnight after the first application and about a week after the second application. The other chemicals did not show any ill-effect after application. Nematology MN4 — Screening of clones for tolerance to the burrowing nematode — Rado- pholus similis — replicated — (1968) Three tanks, 15 ft x 5 ft x 1 ft, containing soil infested with the burrowing nematode, Radopholus similis, were planted with pepper cuttings on 18.3.69 so as to build-up the nematode population, for the necessary tests. No weeding Gramoxone Gramoxone every 2 months every 4 months 1289 1467 1350 1510 1528 1525 170 ANNUAL REPORT FOR 1969 Agronomy MAI — Rehabilitation of old tea land at the Mid-Country Station, Kandy — 3 3 factorial — (1969) This trial is to investigate the effect of rehabilitation of old tea land with Guatemala grass, mana grass and legumes for different periods of time, viz no rehabilitation and rehabilitation for 1-year and 2-year periods, on the growth and yield of VP tea. The old tea, in plots, to be rehabilitated for a 2-year period was uprooted and planted with the respective rehabilitation species in June. The plants were lopped and the weight of loppings recorded in Decem­ ber. The experiment is continuing. MA2 — Clone x spacing x bringing into bearing at the Mid-Country Station, Kandy — 3 s factorial — (1969) This experiment commenced in November and measures the effect of three methods of bringing into bearing {viz bending only, cut across early and cut across one year after planting) and three spacings (4 ft x If ft, 4 ft x 2 ft and 4 ft x 3 ft) on the growth and yield of three clones (TRI 2023, DG 39, and DN). MA3 — NPK, Mg and frequency of application on clone TRI 2025 at Ratwatte Estate, Ukuwela — 3 s factorial — (1969) The pre-treatment plucking commenced on 8.7.69. Treatments will be given in January 1970. MA4 — Bringing-into-bearing trial for growth assessments — Randomized blocks — (1969) This experiment is designed to study the effect of different methods of bringing into bearing on the growth of plants of two clones, viz TRI 2023 and DN. The treatments are: (i) bending (if) centering (iii) thumb nail pruning and (iv) 2 years free growth. The experiment was laid down in October. M. K. Vythilingam Drought resistance of clones Two further observations following drought conditions were made on 6.3.69 and 12.3.69 on 16 clones of MVP4. Based on visual observations, marks were given to the clones on their ability to withstand drought. The analysed results are given in Table 1. TABLE 1 — The ability of 16 clones (Experiment MVP4) to withstand drought mes in decreasing order . Score of drought resistance MO 208 4.63 PLLG 2 4.00 MO 114 3.63 CAR 7/10 3.38 MO 146 3.31 MO 116 3; i9 QT4/4 3.00 H l / 5 8 2.81 D W 1 2 2.75 P C G 2 2.75 MO 241 2.63 SEED LDC 2:56 SEED ILLT 2.50 TRI 1114 2.31 TRI 1530 2.31 TRI 2024 2.13 LSD (P < 0 ; 0 5 ) = 1.34 ANNUAL REPORT FOR 1969 171 Vegetative Propagation These experiments were carried out in collaboration with the Plant Phy­ siology Division and the results are presented in detail in the Report of the Plant Physiology Division. MVP1 — Clonal testing at the Mid-Country Station — (1961) This experiment had completed its second pruning cycle in September. The higher yield in most of the clones in the third year than in the second year of the three year cycle is an indication that the pruning cycle could be extended by another year. MVP2 — Clonal testing at Mid-Country Station — (1962) Second year's weekly pluckings of the second pruning cycle of this experi­ ment were completed in July. The yield of 13 of the 16 clones has considerably increased in the second year. Clone KP 204 has yielded over 3,000 lb made tea per acre per year, while seven clones, CH 13, TRI 2016, MPA 1, NK4B29, TRI 2024, 2022 and 2043, have yielded over 2,000 lb and the rest of the high yielders have given over 1,700 lb. MVP3 — Clonal testing at Mid-Country Station — (1963) The first year weekly pluckings of the second cycle were completed in October. ; Clones DG 7 and TRI 2021 have yielded over 1,700 and 1,500 lb made tea per acre per year respectively and four other clones TRI 2024, DG 3, E 7/27 and TRI 2046 have a record of 1,200 lb. MVP4 — Clonal testing at Mid-Country Station — (1964) This experiment has concluded its first 3-year pruning cycle in September. MVP5 — Clonal testing at Mid-Country Station — (1965) This experiment has completed its second year of the first cycle. The yields were realatively very low. MVP6 — Clonal testing at Mid-Country Station — (1966) First year's weekly pluckings were completed in September. The promising clones were PG 2/1 and 18B. MVP7 — Clonal testing at Mid-Country Station — (1967) The nine clones in this experiment will be brought into plucking in January 1970. New Clearing 24,986 plants from 16 clones of varying qualities and 363 bi-clonal seedlings were planted in five and a half acres of rehabilitated land. (These include bringing-into-bearing and spacing trials of the Agronomy Division.) H. B. Ratnayake Technology Inadequate facilities to have the experimental samples tasted and evaluated by a tea taster hampered the experimental progress this year, too. 172 ANNUAL REPORT FOR 1969 MT1 — Quality assessment of clones — (1966) On account of difficulties that arose with having the experimental samples evaluated, further quality assessment of clones at this station was discontinued. However, a series of clonal tests were carried out for Hellbodde Estate, Katu- kitula, and Loolecondera Group, Deltota, and the test samples were evaluated by the respective tea tasters of the two estates. Among the clones tested for Hellbodde Estate, N 3 emerged as a very promising clone (Group 2), while the rest of the clones, namely D 40, H 13/4 and C 21, were found to be of satisfactory quality (Group 3). The clone LC 2 tested for Loolecondera Group also seemed to possess satisfactory quality (Group 3). It would, however, not be possible to reach a definite conclusion on this clone because of the inadequate number of test manufactures carried out. MT4 — Plucking rounds-cum-plucked unit — (1967) This experiment is designed to determine the effect of different plucking rounds (4, 6 and 12 days) arid the standard of plucking units (a bud and either 1, 2 or 3 leaves) on the liquoring characteristics of made tea. The first stage of this experiment which investigated the influence of plucking rounds of four, six and 12 days with the normal standard of plucking of two leaves and a bud, has now been concluded. The results await analysis. The second stage of this experiment investigates the inherent effects of the three types of plucking (a bud and either 1, 2 or 3 leaves) on three different plucking rounds (4, 6 and 12 days) on made tea characteristics, and is in progress. MT5 — Gramoxone (and hand weeding in combination with 3 levels of nitrogen) on made tea characteristics — (1967) This experiment is in its 2nd cycle and in the first year after pruning. Test manufactures for the 2nd cycle have not begun yet because of difficulties in having the samples evaluated. In the present cycle the differences in yields between the weeding treatments were not significant. The difference in yields between the two nitrogen treatments (100 and 200 N per acre per year), how­ ever, were significant. MT6 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels and 3 levels of potash on made tea characteristics — (1967) This experiment, carried out in conjunction with the District Advisory Officer (Mid-Country), studies the effect of calcium ammonium nitrate, sulphate of ammonia and urea, each at three levels and in combination with three levels of potash, on liquoring characteristics of made tea. Difficulties in having an adequate number of test samples, sufficient for statistical analysis, tasted and evaluated impeded the progress of this experiment. The experimental area was pruned in October and further test manufactures will commence on complete recovery from pruning. 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. The experimental plots have been divided into three groups of which the first and the second were pruned in 1968 and 1969 respectively. The third group will be pruned in 1970 so that within a period of three years since the experiment began, tea bushes which are one, two and three years old from pruning are available simultaneously. Manu­ facturing tests for 1969 were held up because of difficulties in having the samples evaluated, but tests will begin when the tea recovers from pruning. ANNUAL REPORT FOR 1969 173 MT8 — Tip content of clones — (1969) Visual comparisons were carried out on the tip content of several clones. The clones under review were compared with a series of standards made up by mixing in certain proportions of teas from a tippy clone (W 2/145) and a non-tippy clone (TRI 2024). Among the clones studied W 3, TGK 2, KP 204 and TRI 2045 seemed to possess high tip content. Further clones are being studied. T. A. Munasinghe Entomology The following experiments were concluded and the results have been published (see the Annual Report for 1968, Part 2) : ME3, ME4 and ME5. ME1 — Ecology of Shot-hole Borer—Hantane, Kandy — (1962) The analysis of voluminous data from six-year (1962-68) records of 'popu­ lation ecology' is in progress. The changes in populations of the borer, both in the air above the crop and in the crop, are being related to the weather factors, viz rainfall, sunshine, temperature and wind speed. Fresh investiga­ tions on the flight behaviour of beetles in relation to weather factors, including humidity, have commenced. Observations to study the effect of temperature on (i) larvae (ii) pupae, and (iii) adults are in progress. Large numbers of larvae, pupae and adults are subjected to varying degrees of temperature, from 40° F to 120° F, with the aim of finding the optimum range of temperature for the borer to successfully live and breed. Studies on bahaviour of the borer are in progress. The response of the beetles to extracts of seedling tea and clones are studied, in collaboration with the Biochemistry Division. The movements of beetles under laboratory condi­ tions are being observed. ME2 — Clonal selection for shot-hole borer tolerance (MVP 1 — MVP 7) — (1966) The investigations on 76 clones of MVP1 (32 clones), MVP2 (16 clones), MVP3 (12 clones) and MVP4 (16 clones) were completed to-date. The existing list of clones at this Station in which the 60 clones of MVP1, MVP2 and MVP3 are arranged in order of yield and other characteristics, viz quality, drought resistance and shot-hole borer tolerance, will be revised to include the 16 clones of MVP4. Further, a reassessment of the borer attack in the 32 clones of MVP1 was done in September, when the clones completed their second pruning cycle. The analysis of these observations is in progress and the results will be published later. ME6 — Control of Shot-hole Borer by mid-cycle applications of heptachlor vs clonal tolerance to borer attack, at Dartry Group, Gampola — (1967) This experiment was concluded in March. This experiment tested clones TRI 2023, CH 13 and KEN 16/3. Bi-monthly borer samplings were carried out. The analysis of results showed that both the treated and untreated plots of clones TRI 2023 and CH 13 and only the treated plot of KEN 16/3, 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. 174 ANNUAL REPORT FOR 1969 Nitrogen Yield Potassium Yield Ob/acre/year) (lb/acre/year) (lb/acre/year) Ob/acre/year) 90 1624 0 1763 180 1924 60 1853 270 2191 120 1952 LSD CP < 0.05) 236 136 XMA3 — Calcium ammonium nitrate, sulphate of ammonia and urea at 3 levels " and 3 levels of potash on seedling tea at Hantane Estate, Kandy — (1966) Post-treatment pluckings were recorded from 23.6.68 - 8.9.69 after which the plots were pruned. None of the treatment effects was significant for this period. The experiment is continued for another pruning cycle. ME7 — A survey of borer infestation in tea — (1969) A systematic survey of borer infestations in tea, starting with the mid- country tea districts, has commenced. The aim of this survey is to relate the distribution of the pest to topographical and climatic factors, and to investigate the causes of any localized distribution. To-date 81 observations in 24 estates covering 12 planting districts have been made. ME8 — A search for biochemical basis for borer infestations of tea — (1969) In collaboration with the Biochemistry Division, tea stems and leaves from both seedling tea and clones, known to have varying degrees of suscepti­ bility to borer infestation, were biochemically analysed to find out whether there was any biochemical basis for differential susceptibility. ! The results obtained to date are inconclusive. The investigations are being continued. ME9 — A comparative assessment of insecticidal control vs inherent tolerance of clone to Shot-hole Borer in MVP1 — replicated — (1969) The clones were pruned in September. The treatment, ie mid-cycle application of heptachlor 20%, at the rate of 6 pints in 80-100 gallons of water per acre, will be given in September 1970, when the clones are 12 months old from pruning. K. Thirugnanasuntharan Extension Experiments XMAl — Calcium ammonium nitrate, sulphate of ammonia and urea at 3 levels and 3 levels of potash on seedling tea at Kallebokka Group, Madulkele — (1966) The experiment was pruned in May. Analyses of yield data from Septem­ ber 1967 to May 1969 showed no significant differences in yield between treat­ ments. The experiment will be continued for another pruning cycle. XMA2 — Calcium ammonium nitrate, sulphate of ammonia and urea each at 3 levels and 3 levels of potash on seedling tea at Wattakele Estate, Madulkele — (1966) The yield responses for a period of 21 months are given in the table below. There were significant differences in yield between different levels of N and K but not for types of nitrogen. ANNUAL REPORT FOR 1969 175 Publications CALNAIDO, D . (1969). Pest ecology in relation to pest control strategies. Bull. Ceylon Planters' Soc. 28, 11-15. THIRUGNANASUNTHARAN, K. & CALNAIDO, D . (1969). Observations on the tolerance and susceptibility of tea clones to shot-hole borer infesta­ tion—1969. Tea Q. 40, 47-52. XMPH1 — Four levels of nitrogen and 3 levels of shade on seedling tea at Kirimetiya Estate, Galaha — (1966) Due to a prolonged strike on the estate, crop was recorded for only six months of the 2nd pruning cycle of the experiment. XMPH2 — Four levels of nitrogen and 3 levels of shade on seedling tea at Kallebokka Group, Madulkele — (1966) The analysis of yield for 18 months after treatment showed a significant difference between the highest and lowest nitrogen, levels only. Nitrogen Yield Ob/acre/year) (lb made tea/acre/year) 0 1083 90 1134 180 1255 270 1354 LSD (at P < 0.05) = 252 XMPH3 — Four levels of nitrogen and 3 levels of shade at Mousagalla Estate, Madulkele — (1966) There were no significant differences in yield between treatments after 1J years of plucking. XMPH4 — Shade vs no shade, Mahousa Estate, Madulkele — (1966) The yield in pounds made tea per acre per cycle (36 months) was as fol­ lows :— Shade 2887 No shade 2818 There was no significant difference in yield between the shaded and un­ shaded plots. M. K. Vythilingam REPORT ON THE UVA STATION Uva Scientific Officer — L. M. de W. Tillekeratne, BSc, MEd General The staff position improved with the transfer of Mr Jayasinghe as Officer- in-Charge of the Agratenne Substation towards the latter part of January. Mr Amarasekera was appointed as a Field Attendant in December. Mr N. L. C. Fernando was transferred to St Joachim and his place was taken by Mr Hassim from St Coombs. With the transfer of Mr Hassim, it has been possible to process a few soil samples daily for nematode counts. General Observations on Advisory Work on Estates Types of inquiries received from estates and other sources predominating during the year dealt chiefly with fertilizer programmes and the introduction of the new fertilizer policy of the Institute. In addition there were inquiries regarding the experimental use of heptachlor as a mid-cycle spray for the control of Shot-hole Borer. Reports of damage by pests especially nettle grubs, Tortrix and mites were very few during the year. As regards mite attacks, many estates, especially in the Haputale Subdistrict, followed the recommen­ dations of the Institute and resorted to prophylactic sprays of acaricides on known mite-prone areas only, in the drought with great success. In general the climatic conditions during the year were more like a normal Uva year in contrast to the weather experienced in 1968. The drought started early in May and continued until mid-September with a few showers of rain in August. Record prices were obtained for teas during the height of the flavoury season. The prolonged drought delayed planting of clearings, and in some cases planting was completed only by December. The latter part of December saw unprecedented heavy rains resulting in serious storm damage to some estates. UA3 — Nitrogen (urea) at 3 levels and 3 methods of application on clonal tea at the Passara Sub-station — (1969) An experiment to test three levels of nitrogen and three methods of appli­ cations of urea was laid down in the old spacing experiment in conjunction with the Agricultural Chemist. Extension Experiments Extension experiments in Uva continued to be managed by the Advisory staff of the Uva Station. Four extension experiments were pruned during the year. Records and treatments will be continued in these experiments after recovery. Green leaf weights recorded have been converted to made tea at 22% outturn, and yields have been calculated on the basis of 4000 bushes to the acre in all results given. XUA1 — Three types of nitrogen at 3 levels at Aislaby Estate, Bandarawela- (1965) The experiment was pruned in October/November 1968, and came into plucking in the middle of 1969. The results of the second cycle have not been analysed as yield figures are available for only a few months. 176 ANNUAL REPORT FOR 1969 177 Nitrogen levels Mean yields Potash levels Mean yields (lb N/acre/year) (Ib/acre/year) (lb K a O /acre/year) (lb/acre/year) 120 2467 0 2510 240 2728 60 2673 360 2660 120 2673 LSD (P = 0.05) 130 130 XUA3 — Three types of nitrogen at 3 levels at Hugoland Estate, Udapussellawa — (1965) This experiment completed the cycle during the year and was pruned in July. The results of the first cycle were statistically analysed and showed no significant responses in yield to the three levels of nitrogen tested or the three types used. XUA4 — NPK at 3 levels and control in all combinations at Hugoland Estate, Udapussellawa — (1965) This experiment completed the cycle during the year and was pruned in July. The results of the first cycle were statistically analysed and showed no significant responses in yield to the three levels of N, P and K. XUA7 — Guatemala, Mana and Napier as rehabilitation species at Telbedde Estate, Badulla — (1965) No significant differences have been observed in the growth of the tea planted on land rehabilitated with the different species. This experiment is concluded. XUA9 — Guatemala, Mana and Napier as rehabilitation species at Nayabedde Estate, Bandarawela — (1965) No significant differences have been observed in the growth of the tea planted on land rehabilitated with the different species. The experiment is concluded. XUA10 — Three levels of nitrogen and 3 levels of Limbux at Cannavarella Group, Namunukula — (1965) This experiment completed its third year. The results obtained in 1969 were statistically analysed and showed no significant responses in yield to the levels of nitrogen or Limbux. XUA11 — Three types of nitrogen at 3 levels at Cannavarella Group, Namunu­ kula — (1965) The results obtained in 1969 were statistically analysed and showed no responses in yield to the nitrogen levels or the types used. XUA2 — NPK each at 3 levels and control in all combinations at Aislaby Estate, Bandarawela — (1965) The experiment has completed three years of post-treatment pluckings. The results for 1969 (Table 1) show a quadratic response to nitrogen, ie the highest level of nitrogen depresses yield as compared to the middle level. There is no response to phosphorus. There is a significant response to potash up to 60 lb KaO per acre. TABLE 1 — Yield response to different nitrogen and potash levels at Aislaby Estate, Bandarawela 120 240 360 Mean 0 1177 1308 1664 1383 60 1209 1442 1660 1437 120 1509 1426 1389 1468 1325 1392 1572 LSD (P = 0 . 0 5 ) — Main effect 102 LSD (P = 0 .05 )— Linear interaction 354 178 ANNUAL REPORT FOR 1969 Potash levels (lb KaO/acre/year) Mean yields XUA13 — Three types of nitrogen at 3 levels at Spring Valley Group, Namunu­ kula — (1965) This experiment completed the cycle in February. Analyses of the results of the first cycle showed no significant responses to either the levels or types of nitrogen. XUA14 — NPK at 3 levels and control in all combinations at Kahagalla Estate, Haputale — (1966) This experiment has completed about three years of post-treatment, pluckings. The results for 1969, given in Table 3, show a highly significant linear response in yield to nitrogen All other effects are not significant. TABLE 3 — Yield response to three levels of nitrogen at Kahagalla Estate, Haputale N levels Mean yield (lb N/acre/year) Ob/acre/year) 120 2750 240 2882 360 3304 LSD {P = 0.05) 257 XUA15 — Three types of nitrogen at 3 levels at Kahagalla Estate, Haputale — (1965) The experiment has completed about three years of post-treatment, plucking. The results for 1969 (Table 4) show a significant linear response to nitrogen. There is no response to the types of nitrogen used. TABLE 4 — Yield response to three levels of nitrogen at Kahagalla Estate, Haputale Nitrogen levels Mean yields (lb N/acre/year) (lb/acre/year) 120 2602 240 2846 360 2960 LSD (P = 0.05) 269 XUA12 — NPK at 3 levels and control in all combinations at Spring Valley Group, Namunukula — (1965) The results for 1969 were statistically analysed and are given in Table 2. These results show a significant linear response to the levels of nitrogen. There is no response to the levels of phosphate or potash. There is also a significant linear x linear interaction between nitrogen and potash. TABLE 2 — Yield response to different levels of nitrogen and potash at Spring Valley Group, Namunukula Mean yields (lb/acre/year) Nitrogen levels (lb N/acre/year) ANNUAL REPORT FOR 1969 179 XUA16 — Three levels of nitrogen and 3 levels of Limbux at Hugoland Estate, Udapussellawa — (1965) This experiment completed its cycle and was pruned in July. Analyses of results of the first cycle showed no significant responses to either the levels of nitrogen or the levels of Limbux. A. R. M. Hassim Extension Activities Exhibitions The Institute participated in the National Exhibition held at Badulla. Estate Trials Assistance was given to Haputale and Dyraaba Estates in conducting pruning trials. 1968 Drought A comprehensive report on the effects of the severe drought experienced in 1968 in the Uva Province was submitted to the Board of Control. In order to facilitate the writing of this report a questionnaire was sent to 25 estates selected at random in the subdistricts. Substations Gonakelle Activities on this sub-station continued to be confined chiefly to clonal testing and miniature manufacture. Results obtained from clonal trials during the year are given in the Report of the Plant Physiology Division. Agratenne The transfer of the selected land to the Institute is still pending. Four meetings of the Uva Subcommittee on Agratenne were held during the year, the first meeting being held on the Substation itself. Mr M. Clarke visited the Substation twice during the year and submitted useful reports. New Clearing 1 The clonal pruning experiment planted in 1967 was resupplied towards the end of the year, and came into light plucking in December. New Clearing 2 The five acres replanted in 1968 were resupplied towards the latter part of the year. The treatments were applied by the Agronomy Division during the year. New Clearing 3 Two and a half acres of scrub land were planted during the N.E. monsoon in the form of an experiment to test two sizes of planting holes and tren­ ching with and without phosphate in the holes. Details of this experiment are included in the report of the Agronomy Division. 180 ANNUAL REPORT FOR 1969 New Clearing 13 B Seven and a half acres of old tea were planted after rehabilitation. The planting took the form of two experiments: (a) to test thatching, Crotala­ ria rows interplanted and cultivation, and (b) NPK fertilizer trial. Details of these experiments are included in the report of the Agronomy Division. A well was dug just below the bungalow to supplement the present water sheme. The area under cultivation was fenced during the year to prevent damage from stray cattle. Tenders were called for the construction of one set of minor staff quarters, an office, a storeroom and a garage. Crop Diversification Small areas of scrub land were brought under mango, citrus, papaw and coconut. Three timber species were planted in a five-acre, old seedling area brought back into plucking for this purpose. Acknowledgements Our sincere thanks are due to all Managers, Superintendents and Assis­ tants of estates on which extension experiments were conducted for their ready co-operation during the year and to all Managers and Superintendents who replied the questionnaire on drought. REPORT ON ST COOMBS ESTATE Agriculturist — L. A. Seevaratnam, BSc General Mr W. Delpagoda was appointed Storekeeper/Clerk from 16th August. The staff on St Coombs struck work on 1st June over demands relating to the payment of increased salaries and bonus. The strike was called off on 27th July. Estate work continued during the period the staff were on strike. Acreage as at 31st December, 1969 A R P Seedling tea in bearing 158 1 18 VP tea in bearing 88 2 23 Young VP tea 12 2 10 Land under rehabilitation 20 3 27 Area reserved for clonal cuttings 7 0 17 Other land (fuel clearings, buildings roads, gardens, etc) 135 3 08 423 1 23 Crop St Coombs produced 404,741 lb made tea, which exceeded the estimated crop of 364,800 lb by 39,941 lb. The yield per acre was 1,642 lb. The yield per acre per month for St Coombs Estate from 1965 to 1969, the total rainfall, the number of wet days and the average quantity of nitrogen applied each year is given in Table 1. TABLE 1 — Yield per acre per month for St Coombs from 1965-1969, total rainfall, the number of wet days and the average quantity of nitrogen applied each year Month 1969 1968 1967 1966 1965 January 172 141 116 155 136 February 121 75 109 117 88 March 80 82 106 151 97 April 184 177 140 149 183 May 235 178 187 161 177 June 110 173 134 132 129 July 117 100 105 138 108 August 117 136 120 147 87 September 122 169 118 123 106 October 131 181 120 122 125 November 122 220 152 141 137 December 131 181 146 127 137 TOTAL . . 1642 1813 1553 1663 1510 Total rainfall (in.) 91.67 90.59 83.96 70.94 93.21 No. of wet days 206 192 202 188 204 Average N per acre per year (lb) 159 222 248 248 184 N P 2 O 5 K a O Clonal tea/seedling tea yielding above 1600 lb per acre per year, over the cycle 300 30 90 Seedling tea yielding below 1600 lb made tea per acre per year, over the cycle 200 20 60 Seedling tea yielding below 1200 lb made tea per acre per year, over the cycle 160 20 60 181 TABLE 2 — Monthly yields of fields and fertilizers applied from January to December, 1969 Type of nitrogen Field No. fertilizerf Fertilizer Monthly yields (lb per acre) 1 2 3 3* 4 6 7 8 9 10 Urea S/A S/A S/A Urea S/A Urea S/A S/A S/A 10 (Clonal) S/A 11 S/A 12 Urea 13 Urea 14 S/A 15 Urea 16 CAN 17 S/A (lb per annum) Aug. Sep. Oct. Nov. N P K Jan. Feb. Mar. Apr. May Jun. Jul. 300 30 90 176 133 62 247 249 102 84** 67 77 89 94 200 20 60 175 73 57 178 168 93** 9 7 0 6 5 300 30 90 214 123 42 176 208 190 192 164 168 200 177 200 55 120 48 107 60 115 118 81 138 149 121 110 106 200 20 60 145 100 84 120 206 112 128 107 110 122 124 200 20 60 158 88 56 157 219 94 125 65 70 73 60 200 20 60 195 113 95 131 303 100** 124 95 70 88 90 300 30 90 182 159 57 219 240 159** 132 157 112 142 116 200 20 60 115 112 82 169 157 94 102 120 134 128 112 200 20 60 234 152 135 262 387 168 174 100 299 221 196 200 20 60 91 76 104 83 230 115 127 179 105** 75 67 200 20 60 242 106 77 223 290 113 189 148 157 185 158 200 20 60 163 140 59 210 220 92 94 136 149 143 143 200 20 60 143 108 98 147 190 55** 30 09 11 45 32 200 20 60 202 161 90 282 264 90 119 237 155 192 180 200 20 60 181 168 203 165 388 181 177 161 249 204 210 300 270 120 76 210 311 109 219 270 224 277 258 300 30 90 277 151 215 136 430 171 129 182 198 216 195 t CAN — Calcium ammonium m'trate S/A — Sulphate of ammonia Urea — Prilled urea • Experimental area ** Pruned TABLE 3 — Working of St Coombs Estate for the year 1969 in comparison to previous years Total crop (lb made tea) Yield (lb made tea per acre) Net sale price (cents per lb) Cost of production (cents per lb) Estimated Actual Gross profit (Rs) TRI contribution (Rs) 419,040t 1642 186* 188* 171* 151,652* Nil 475,502 1813 229 185 165 282,115 Nil 457,727 1553 203 181 183 90,402 Nil 431,697 1663 218 161 170 189,302 Nil 419,338 1510 224 153 148 287,862 63,763 t Includes 14,299 lb crop, secured on bought leaf * Subject to verification by the Auditors 184 ANNUAL REPORT FOR 1969 Fertilizer application All fields received phosphate, potash and nitrogen in the form of mixtures, except certain experimental areas. The levels of nitrogen, phosphate and potash were determined on the yield potential of each field, and were as follows :— The fertilizers were applied in the form of mixtures as well as straight nitrogenous compounds. Prilled urea was used on approximately l/3rd of the total tea acreage. Table 2 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 3. Cultural Operations All fields received applications of zinc sulphate. All fields, except certain experimental areas, were under fungicidal protection against Blister Blight during both monsoons. Field No. 1 Seedling tea — 1A-3R-35P VP tea — 18A-OR-05P Clones planted — TRI 777, 2016, 2022, 2023, 2024, 2025, 2026 Land under rehabilitation — 2A-0R-0P Last pruned — 1967 (8A) and 1969 (8A) Yield per acre 1968 — 2031 1b Yield per acre 1969 — 15191b Type of N — Prilled urea Quantity of NPK (lb) — 300 N; 30 P; 90 K Shade — Erythrina lithosperma, Grevillea robusta Experiments — PHI (0.5A), N7 (0.25 A), N15 (0.25A), N21 (0.25 A) About eight acres of this field which completed a five-year pruning cycle were pruned this year. Pruning was done at the beginning of the South West Monsoon. Rim lungs were left at pruning and removed at bud break. The Grevillea robusta shade trees in this field which had been ring-barked in previous years were felled after the trees were quite dead. Seedling tea — Nil VP tea — 7A-1R-23P Clones planted — TRI 740, 777, 2023, 2024, 2025, 2026, 2039, 2142, DT 1, DT 95, E7/27 Planting year — 1964 Last pruned — 1969 Yield per acre 1968 — 1351 lb Yield per acre 1969 — 826 lb Type of N — Sulphate of ammonia (T 200) Quantity of NPK (lb) — 200 N ; 20 P; 60K Shade — Nil Experiments — PH3 (1.78A), PH12 (0.5A), VP12 (0.2A) This field completed five years from planting and was pruned this year. Rim lungs were left at pruning and removed at bud break. ANNUAL REPORT FOR 1969 185 Field No. 3 Seedling tea Shade Yield per acre 1969 VP tea—1965 planting Clone 1966 planting Clones 1967 planting Clones 1968 planting Clones 1968 planting 1969 planting Clones Yield per acre 1969 4A-2R-0P (Experimental) Erythrina lithosperma, Acacia pruinosa (Experimental) 1258 lb 10A-0R-15P D T I 4A-2R-12P TRI 740, 2024, 2025, 2142, 62/3, 62/5, E7/27, CY9, KEN 16/3 7A-0R-25P TRI 2023, 2025, K 145, TC9 4A-2R-12P TRI 26, 2023, 2025, 2027, 2043, 2142, 62/9, DTI, TC9, NL3/1, KEN16/3 Without rehabilitation but after fumigation with methyl bromide 2A-0R-20P 5A-OR-02P TRI 2023, 2025, 2043, 2142, DT 1, TC 9, other clones in small numbers 2021 lb The area uprooted in 1968, which had been under Gautemala grass, was planted this year. Planting was done in blocks with a view to utilizing these areas for future experimental work. A total number of 25,117 plants were put out. Approximately one acre of land in this field was planted in potato in November, 1968 and later with tea. This area was planted without rehabilit­ ation and without fumigation. Field No. 4 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade Experiments 30A-2R-0P In ravines only 1967 1355 lb 1472 lb Prilled urea 200 N ; 20 P; 60 K Nil PH25(0.8A), P20 Field No. 5 Seedling tea VP tea 1968 planting Clones 1969 planting Clones Land under rehabilitation Shade Nil 2A-2R-10P TRI 2043, NL 3/1, KEN 16/3, K 145 5A-0R-0P TRI 2043, 2023, 2151, DN, other clones 12 acres Erythrina lithosperma An area of 1A-OR-38P of old seedling tea was uprooted during the course of the year and land handed back to the Nematology Division. Approximately 12 acres of land which had been under Guatemala grass were planted this year. Planting was done in blocks with a view to using these areas for future experi­ mental work. An area of approximately 12 acres continued to be under Guatemala grass and will be planted in 1970. 186 Field No. 6 ANNUAL REPORT FOR 1969 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade Experiments 9A-0R-0P OA-1R-35P 1966 1863 lb 1263 lb Sulphate of ammonia 200 N; 20 P; 60 K Grevillea robusta PH33 (6A) Some Grevillea robusta trees which had been ring-barked previously and which were quite dead were felled this year. Approximately 6 acres of this field which is experimental were pruned this year although the pruning cycle had not been completed. The pruning was undertaken for the Physio­ logy Division in connection with an experiment. Field No. 7 Seedling tea VP tea 1962 planting Clones Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade 1964 planting Clones Last pruned Shade Experiments — Nil — TRI 740, 777, 2023, 2024, 2025, 2026, 2043, 2142, 2151, DT 95, TK 45 — 1966 — 27571b — 1545 1b — Prilled urea — 200 N; 20 P; 60 K — Nil , — TRI 740, 777, 2016, 2023, 2024, 2025, 2026, 2039, 2142, DT 1, DT 95, E 7/27 — 1969 — Nil — VP2 (1.5A), P18 (1A), A8 (2.4A) 6A-0R-18P in this field completed five years from planting, and was pruned this year. Rim lungs were left at pruning and removed at bud break. Field No. 8 Seedling tea VP tea Clones Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade Experiments Nil 8A-3R-2P TRI 777, 1114, 2024, DT 1, DT 95 1969 3038 lb 1818 lb Sulphate of ammonia 300 N ; 30 P; 90 K Nil A8 (2-4A), A9 )1A), VV1 (0.8A), W2 (0.5A), W6 (0.5A), VP1 (1.75A), VP2 (1. 5A), VP11 (0.05A), VP19(1.75A) Field No. 9 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK 0b) Shade Experiments 26A (Estate plucking 15|A) Nil 1967 1349 lb 1451 lb Sulphate of ammonia 200 N; 20 P; 60 K Grevillea robusta, Erythrina lithosperma A2 (2.4A), A4 0.4A), PH26 (0.01 A), VP10 (0.17A), VP14 (0.05A), W7 (0.01A), P14 (1A), P19 (7A), P31 (0.1A), P32 (7A), P56 (0.3A), P l l (0.01A), P57(0.2A) ANNUAL REPORT FOR 1969 187 Field No. 10 12A-2R-0P CEstate plucking) 1967 1885 lb 2492 lb Sulphate of ammonia 200 N; 20 P; 60 K Grevillea robusta and Erythrina lithosperma 5A-2R-2P TRI 23, 740, 777, 2016, 2021, 2023, 2024, 2025, 2026 , 2027, KEN 16/3, NL 3/1, TC 9, 2043 Clonal areas constantly pruned for taking cuttings 2563 lb 1320 lb Sulphate of ammonia 200 N; 20 P; 60 K Nil An area of 0A-3R-02P had been planted during the North East Monsoon of 1969. The plants were bent twice during the course of the year. No Couch grass grew in the areas that had been fumigated at doses ranging from \ lb to 2 lb methyl bromide, indicating successful control of Couch grass at these dosages. Field No. 11 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade Experiments 17A-0R-0P Nil 1966 19041b 2033 lb Sulphate of ammonia 200 N; 20 P; 60 K Nil A16 (1.7A), PH22 (0.17A), VP15 A further quarter acre of this field was uprooted by the Agronomy Divi­ sion for an experiment on rehabilitation. Field No. 12 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (ib) Shade Experiments 29A-3R-0P (Estate plucking) Nil 1965 1933 lb 1687 lb Prilled urea 200 N ; 20 P; 60 K Nil PH13 (1.78A), PH21 (0.04A), P20 (0.05A) The experiments allowing rows of tea to grow up as windbreaks were concluded this year. The windbreaks of tea were pruned and brought into plucking with the rest of the tea on this field. The experimental plots of the Physiology Division were handed back to the estate. As the tea in these areas were overgrown these plots were also pruned. Field No. 13 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK Ob) Shade Experiments 18A-1R-0P O^state plucking 15A) Nil 1969 1799 lb 960 lb Prilled urea 200 N ; 20 P; 60 K Nil A5 (0.7A), A7 (0.7A), A12 (1.7A), PH5 (1.44A), P20, P26(1A) Seedling tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade VP tea Clones Pruning Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK Ob) Shade 188 ANNUAL REPORT FOR 1969 This field completed five years from the last prune this year, and was pruned with the onset of the South West Monsoon. Field No. 14 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK Ob) Shade Experiments 12A-2R-0P In cleared ravines only 1966 1767 lb 21141b Sulphate of ammonia 200 N; 20 P; 60 K Nil VP15, P20 Nickel chloride continued to be used on this field for blister blight control in an experiment on disease forecasting conducted by Plant Pathology Division. Field No. 15 Seedling tea VP tea Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade Experiments 2R-1R-0P Nil 1966 2311 lb 2476 lb Prilled urea 200 N; 20 P: 60 K Grevillea robusta Nil Field No. 16 Seedling tea — Nil VP tea — 4A Clones — TRI 2024 Last pruned — 1965 Yield per acre 1968 — 22441b Yield per acre 1969 — 25831b Type of N — Calcium ammonium nitrate Quantity of N — 3001b Shade — Nil Experiments — P29 (0.6A), P30 (0.6A), P58 (0.2A) No phosphate or potash was applied on this field for the fourth year since pruning, and this field continued to receive its nitrogen as calcium ammonium nitrate since the last prune. No serious set back was noticed so far. The 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 grass during the year. Field No. 17 Seedling tea VP tea Clones Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of NPK (lb) Shade Experiments — Nil — 4A-3R-0P — TRI 777, 2024, 2025 — 1965 — 26351b — 2491 lb — Sulphate of ammonia. — 300 N ; 30 P; 90 K — Nil — Nil REPORT ON ST JOACHIM ESTATE Superintendent — G. S. Muttettuwegama General Mrs M. N. Devariyam was appointed Head Teacher of St Joachim Estate School. All other staff appointments remained unchanged. The entire estate staff and a few labourers of St Joachim went out on strike on 1st June and returned to work after 88 days, on the 28th of August. The rainfall recorded for the year was again low and July was unusually dry.. Heavy rains fell in May and a minor flood was experienced. The Hidellena/St Joachim PWD road was improved during the year. Acreage as at 31st December 1969 A R P Seedling tea in bearing 204 0 00 VP tea in bearing 47 1 00 Young VP tea 58 0 38 Seedling tea uprooted for replanting 6 3 00 Nurseries 1 3 11 Other land (Paddy, buildings, roads, line-gardens, 98 ravines and wasteland, encroachments, etc) 0 17 416 0 26 Crop An excess of 2466 lb of made tea was recorded against an estimate of 291,000 lb for the year. The yield per acre for the year was 1142 lb. A fairly good standard of plucking was maintained throughout the year and the plucking rounds were kept at 5 and 6 days. The yield per acre per month for St Joachim from 1965 to 1969, the total rainfall, number of wet days and the average quantity of nitrogen applied 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. Table 3 shows the nett sale average, cost of production and profit or loss. TABLE 1 — Yield per acre per month for St Joachim from 1965 to 1969, total rainfall, number of wet days and average quantity of nitrogen applied each year 196 Month 1969 1968 1967 1966 January 111 119 77 92 94 February 58 48 96 103 57 March 98 107 66 104 121 April 98 83 82 126 88 May 128 84 92 108 100 June 113 80 70 44 101 July 80 81 72 16 91 August 60 86 82 3 102 September 90 97 77 97 101 October 89 109 107 70 116 November 110 110 125 83 110 December 107 98 119 90 110 1,142 1,102 1,065 936 1,191 Total rainfall (in.) 149.43 No. of wet days 235 Average N per acre per annum (lb) 133 146.52 229 149 147.06 236 144 132.78 222 134 166.15 223 144 189 TABLE 2 — Monthly yield of fields from January to December 1969 Fertilizer and type Total N Ob) Monthly yields (lb/acre) Sep. Oct. Nov. Dec. Field No. of nitrogen* per acre Jan. Feb. Mar. Apr. May Jun. Jul. Aug. 1 Urea, P & K 691b N. One se­ parate applica­ 106 108 93 tion of P & K 116 78 107 119 137 143 106 100 104 2 800 mrxt. & 110 115 91 635 mixt. 105 123 56 100 89 121 110 91 97 122 3A 1350 mixt. 200 150 52 120 103 229 170 102 73 141 168 104 227 3B 1350 mixt. 166 47 28 41 54 123 112 104 49 114 116 148 148 3C T 200 mixt. T 200 @ i oz per plant per appl. in 26 1 applications 84 61 56 47 46 3D S/A 74 69 43 135 77 90 — — — 4 800 mixt. & 20 31 105 80 635 mixt. 105 120 58 98 113 137 144 100 P 5 635 mixt. 105 85 50 76 80 41 P 32 54 83 66 81 88 6 800 mixt. & 113 100 105 635 mixt. 105 116 70 83 103 142 113 105 89 125 7 800 mixt. & 21 51 68 60 96 635 mixt. 105 136 56 114 95 130 104 15 8 T 200 mixt. T 200 @ i oz & I oz per plant per appl. in 4 appli­ cations 33 111 83 9 1350 mixt. 166 128 26 46 72 93 P 14 29 — 10A 1400 mixt. 201 153 59 144 138 231 369 237 127 235 182 • 281 230 10B 1400 mixt. 201 107 57 183 139 204 106 56 18 19 75 148 116 *635 NPK mixture is composed of:— 500 lb sulphate of ammonia (105 lb N) 70 lb saphos phosphate (19.25 P 2 0 5 ) 65 lb muriate of potash (39 lb K a O) 635 lb NPK mixture 1350 NPK mixture is composed of:— 950 lb sulphate of ammonia (199.5 lb N) 200 lb saphos phosphate (55 lb P 2 0 5 ) 200 lb muriate of potash (120 lb K a O) 1350 lb NPK mixture S/A — Sulphate of ammoaia 1400 NPK mixture is composed of:— 1150 lb sulphate of ammonia (241.5 lb N) 100 lb saphos phosphate (27.5 lb P a O s ) 150 lb muriate of potash (90 lb K s O) 1400 lb NPK mixture TABLE 3 — Working of St Joachim Estate for Total crop sold Yield Nett sale price Year (lb made tea) (lb made tea per acre) (cents per lb) 1969 286,905 1,142 1.62 1968 269,532 1,102 1.73 1967 272,907 1,106 1.61 1966 245,125 936 1.45 1965 325,028 1,191 1.68 the year 1969 in comparison with previous years Cost of production Gross profit TRI contribution Actual profit (cents per lb) Estimated Actual (Rs) (Rs) (Rs) 178 171 Nil 193 180 — 26,152 Nil — 26,152 148 180 — 60,869 Nil — 60,869 160 175 —118,651 Nil —118,651 152 142 + 77,381 7,911 + 69,470 192 ANNUAL REPORT FOR 1969 Cultural Operations It was possible to complete all cultivation work during the year. Some fields did not receive the full quota of fertilizer, because the lorry driver was not available to transport fertilizer to the fields, during the strike. Field No. 1 Seedling tea (infilled with VP tea) Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 40 acres April 1968 733 lb 1,317 lb Urea 69 lb per acre in 2 applications No shade, except in 6 acres, retained for ex­ perimental work Gramoxone sprayed on 25 acres in February; Diuron,sprayed on 25 acres in March/April, September/December Contract (hand weeding) 9 acres done monthly Research section weeded 6 acres LPH5 (0.5A), LW23 (0.06A) Zinc sulphate was applied as a foliar spray in April and December at the rate of 5 lb per acre per round. Three blocks of about an acre each, where the ground is rocky and not suitable for replanting in tea, have been planted out with Eucalyptus camuldulensis, Eucalyptus saligna and Pinus caribea in the existing tea itself, as a diversification crop. Field No. 2 Seedling tea (infilled with VP tea) Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 28A-1R-0P May 1968 8291b 1,225 lb Sulphate of ammonia 105 lb per acre in 3 applications Nil Gramoxone sprayed on 17J acres in February; Diuron sprayed on 17-i acres in March/April, September and November/December Contract (hand weeding) done in 2 acres monthly 9 acres were weeded by the Research Station LW13(0.8A) Zinc sulphate was applied as a foliar spray in April and December at the rate of 5 lb per acre per round. Field No. 3D Seedling tea (infilled with VP tea) Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 6A-2R-20P May 1967 1,003 lb 6241b Sulphate of ammonia 73 lb per acre in 2 applications Nil Gramoxone sprayed on 6-| acres in February; Diuron sprayed in April Nil The uprooting of old tea in this area was started in September for re­ planting in 1970. New clearings The three clearings were on old tea land. ANNUAL REPORT FOR 1969 193 Field No. 3A VP tea Planted Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 9A-1R-0P 1966 October 1967 at 14 in. 1,388 lb 1,739 lb Sulphate of ammonia 200 lb per acre in 6 applications Nil Hand weeding done monthly LVP7 (0.75A), LW32 (0.1 A), LW33 (0.35A) Zinc sulphate was applied as a foliar spray in May and December at the rate of 5 lb per acre per application. Field No. 3B Seedling tea VP tea Planted Last pruned Yield per acre—1968 (Nov. — Dec.) Yield per acre—1969 Type of N Quantity of N—1969 Shade Weeding Experiments 1A-2R-32P 18A-3R-08P 1967 August 1968 at 14 in. 81 lb 1,084 lb Sulphate of ammonia 166 lb per acre in 5 applications Nil Hand weeding done monthly LA9 (0.73A), LA18 (0.16A), LA34 (0.73A) Field No. 3C VP tea Planted — 13A-2R-20P — 1969 In two small blocks of this clearing where the ground is rocky and not suitable for replanting in tea, a variety of Bamboo (Dendrocalamus strictus) has been planted out as a diversification crop. The fertilizer applied to the tea area was T 200 mixture at the rate of \ oz per plant in 2 applications. Clone Plants Clone Plants TRI 2023 49,077 MT 18 147 TRI 2025 13,500 W/2/145 147 M 2 0 147 S 106 147 H 13/4 147 TRI 2026 147 TRI 2027 147 NK4B29 147 KEN 16/3 147 CW 21 147 TRI 2022 147 TRI 2021 147 PCG2 147 H 1/58 147 MPA 1 147 TRI 2025 147 Clone TRI 2045 PUH 5 GMT 9 TRI 2042 DG 39 TRI 2151 DG 7 TRI 2024 Plants 147 147 147 147 147 147 147 147 Experiment LA37(0.24A) Field No. 4 Seedling tea (infilled with VP tea) Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade . Weeding Experiments 28A-1R-0P July 1969 1,643 lb 1,0061b Sulphate of ammonia 105 lb per acre in 3 applications Nil Gramoxone sprayed on 26 acres in February; Diuron sprayed on 26 acres in April, August/ September and December Research Section weeded 2J acres Nil 194 ANNUAL REPORT FOR 1 9 $ Zinc sulphate was applied as a foliar spray in February, May and Decem­ ber at the rate of 5 lb per acre per application. Recovery after pruning was good. Field No. 5 Seedling tea (infilled with VP tea) Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 35A-1R-OP May 1969 1,157 lb 7361b Sulphate of ammonia 105 lb per acre in 3 applications Nil Gramoxone sprayed on 29£ acres in February; Diuron sprayed on 29J acres in April, August and November Contract (hand weeding) done in 6 acres monthly Nil Zinc sulphate was applied as a foliar spray in February and December at the rate of 5 lb per acre per application. Recovery after pruning was good. Field No. 6 Seedling tea (infilled with VP tea) Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 29A-3R-0P June 1968 869 lb 1,264 lb Sulphate of ammonia 105 lb per acre in 3 applications Nil Gramoxone sprayed on 20} acres in February; Diuron sprayed on 20j acres in April, August/ September and November Contract (hand weeding) 9 acres done monthly Nil Zinc sulphate was applied as a foliar spray in February and December at the rate of 5 lb per acre per application. Field No. 7 Seedling tea (infilled with VP tea) Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 42A-1R-0P June 1969 1,3171b 946 lb Sulphate of ammonia 105 lb per acre in 3 applications This field has been divided into 6 blocks.—In three of these blocks the shade trees (Gliri- cidia maculatd) have been retained and in three blocks the shade trees have been up­ rooted Gramoxone sprayed on 38 acres in February/ March—Diuron sprayed on 38 acres in April, August/September and November Contract (hand weeding) done in 4J acres monthly Nil Zinc sulphate was applied as foliar spray in February and December at the rate of 5 lb per acre per application. Field No. 8 Replanting without reconditioning of old tea land in 1968 VP tea Experiments 42A — LA36(0.5A), LA31(0.15A) ANNUAL REPORT FOR 1969 195 This clearing has made very satisfactory progress. The fertilizer applied was T200 mixture at the rate of \ oz per plant per application in the 1st and 2nd applications and § oz per plant per application in the 3rd and 4th applications. Field No. 9 Replanted in 1966 on old rubber land VP tea Last pruned - Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 3A-2R-32P July 1969 9491b 635 lb Sulphate of ammonia 166 lb per acre in 5 applications Nil Hand weeding done monthly Nil Zinc sulphate was sprayed as a foliar spray in February, May and December at the rate of 5 lb per acre per application. Field No. 10A VP tea Planted Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding Experiments 10A-0R-0P 1964 June 1968 1,026 lb 2,386 lb Sulphate of ammonia 201 lb per acre in 5 applications Nil Hand weeding done monthly LA10 (0.93A), LA11 (0.7A), LA14 (0.47A) Zinc sulphate was applied as a foliar spray in April and December at the rate of 5 lb per acre per application. Field No. 10B VP tea Planted Last pruned Yield per acre 1968 Yield per acre 1969 Type of N Quantity of N—1969 Shade Weeding 6A-2R-0P 1965 July 1969 1,737 lb 1,228 lb Sulphate of ammonia 201 lb per acre in 5 applications Nil Hand weeding done monthly Zinc sulphate was applied as a foliar spray in February, May and Decem­ ber at the rate of 5 lb per acre per application. Pests and Diseases Infestations of Red Rust were noticed in some fields, particularly in the drier months. Low-country collar and branch canker was evident in new clea­ rings where the soil was shallow. Factory Teas manufactured were mainly of the orthodox type for the Middle East Market. A small quantity of CTC teas were manufactured by the Research Station. No new machinery was installed in the factory during the year. METEOROLOGICAL OBSERVATIONS—1969 TEA RESEARCH INSTITUTE OF CEYLON, ST. COOMBS, TALAWAKELE. TEMPERATURES °F RELATIVE HUMIDITY SUNSHINE RAINFALL RAINY DAYS -4-* 0> CO (A cd vi u N co IH Q £ £ Q £ £ \-> o £ | £ VI L. 3 9 >> S o 5 ye a g 5 y ea e & 8 a 3 S & 3 a 3 £ 3 £ 1 3 6 x; a c Q Vi 0> Vi M ax i '5 if is '5 is S as s '£ is a . s > < 4= O c (5 6 > < >. a 0 D iff A ve January .. 73.8 65.1 55.2 52.8 48.3 84.5 63.4 6.80 + 0 42 1 .84 —l 20 7 — 2.96 February .. 75.8 64.6 53.7 50.1 48.1 78.1 55.1 8.60 + i 59 2 .43 —0 05 9 + 2.16 March .. 78.1 65.9 54.1 50.6 50.5 79.0 52.5 8.60 + i 29 3 .63 —0 90 7 — 4.08 April .. 76.7 69.3 60.3 59.1 57.1 92.6 68.9 6.30 —0 25 12 .34 + 5 75 22 + 5.72 May .'. 72.7 67.9 61.5 61.0 58.4 95.5 78.6 4.40 —0 99 12 82 + 4 27 23 + 5.20 June .. 69.2 66.0 60.9 59.9 57.8 95.9 85.4 3.50 —0 05 10 59 —1 17 24 + 1.08 July .. 68.6 64.7 59.2 58.3 56.9 95.3 82.0 4.00 + 0 66 6 35 —3 43 19 — 5.00 August .. 73.8 65.5 59.0 58.3 56.2 93.9 72.5 5.90 + 2 46 4 60 —4 38 17 — 6.32 September . .. 70.4 65.9 59.4 58.5 56.7 94.3 75.2 5.67 + 1 44 11 80 + 3 35 13 — 6.28 October .. 72.1 66.6 58.0 56.8 54.3 92.7 75.1 4.63 + 0 06 10 22 + 0 07 23 + 2.52 November . . 73.2 66.1 57.7 56.1 52.5 91.2 70.3 5.94 + 0 67 5 00 —2 65 11 — 7.76 December . 72.2 66.0 58.1 57.0 54.3 93.6 72.9 3.76 —1 61 7 11 + 1 87 14 + 0.28 73.1 66.1 58.1 56.5 54.3 90.1 71.0 5.68 + 0 47 88 73 + 1 53 189 —15.44 O S > z . > w o H, *n O MEANS TOTALS METEOROLOGICAL OBSERVATIONS THE TRI LOW-COUNTRY STATION, ST JOACHIM, TEMPERATURE °F RELATIVE HUMIDITY SUN­ SHINE -1969 RATNAPURA. RADIATION RAINFALL RAINY DAYS MONTH M ax im um D ry M ax im um W et M in im um D ry M in im um W et M in im um G ra ss Fr om M ax im um Te m pe ra tu re Fr om M in im um T em pe ra tu re M ea n ho ur s pe r da y M ea n pe r da y ° F In ch es D iff er en ce fr om a v er a ge (25 yr s) D ay s D iff er en ce fr om a v er a ge (25 yr s) January 89.8 78.7 70.1 69.5 68.0 56.0 97.0 5.90 149.1 1.63 — 4 .35 7 + 5 February 92.8 78.8 70.8 70.6 68.9 51.0 99.0 7.15 157.7 7.89 + 1 .39 9 + 3 March 94.2 80.6 71.9 71.7 70.3 53.0 100.0 6.80 158.7 3.53 — 5 .98 12 — 5 April 92.8 82.5 74.5 74.2 74.2 63.0 98.0 4.35 159.6 16.63 + 3 .27 26 + 5 May 88.9 82.0 73.8 73.5 73.0 73.0 98.5 2.67 149.1 42.34 + 26 .68 29 + 7 June 87.0 80.3 74.1 73.4 73.3 74.0 97.0 4.49 149.8 14.73 — 2 .12 28 + 3 July 88.0 78.7 74.3 73.0 72.2 64.0 93.0 5.64 149.8 1.75 —10 .48 17 — 6 August . 88.4 79.4 72.5 71.9 70.7 66.0 98.0 5.54 150.9 10.16 — 1 .80 25 + 1 September ... 88.0 79.6 73.1 72.4 71.0 67.0 97.0 6.12 152.9 10.96 — 3 .65 19 — 4 October 89.2 79.8 72.3 71.9 71.3 64.0 98.0 5.03 155.3 18.17 — 1 .04 25 + 3 November ... 89.0 79.5 71.8 71.1 70.9 64.0 96.5 5.50 154.8 10.79 — 2 .38 18 — 2 December 89.0 79.7 71.6 71.1 70.4 64.5 98.0 4.60 150.5 11.30 + 3 .26 17 + 2 89.8 80.0 72.6 72.0 71.2 63.3 97.5 5.32 153.2 149.88 + 2 .80 232 + 12 > z at a > !*> tn. o H. o v MEANS TOTALS METEOROLOGICAL OBSERVATIONS—1969 THE TRI MID-COUNTRY STATION, KANDY TEMPERATURE °F RELATIVE HUMIDITY SUNSHINE RAINFALL RAINY DAYS D ry W et D ry W et fr om yr ) fr om ly r) fr om MONTH | | § | | a 3 i o u a * * s 8 "S a 3 I a "8 m ini iff er e er a g ch es iff er e er a g 1 iff er e er ag i s 2 s S s-s a a s Q % January ... — — — — — 6.93 + 0 . 3 2 4.10 — 0.53 7 — 4 February ... 83.9 71.5 64.7 61.3 82.0 52.8 8.44 + 0 . 9 2 1.40 — 2.29 5 — 3 March ... 86.7 73.4 66.5 64.7 90.5 51.5 8.67 + 1.53 1.96 — 2.78 4 — 5 April ... 86.4 77.0 69.3 68.1 93.8 64.4 7.04 - 0 . 2 4 6.79 — 1.99 17 + 1 May ... 83.0 76.1 69.8 68.1 91.5 72.5 5.30 —1.95 9.91 + 2.68 17 + 2 June 79.8 74.1 68.7 66.9 91.3 75.7 5.33 —0.86 5.99 — 1.71 21 + 1 July ... 80.2 72.4 67.9 65.5 87.7 67.8 5.99 + 0 . 3 1 2.23 — 5.53 15 — 5 August ... 82.2 73.4 67.0 64.7 88.4 65.0 7.04 + 1.00 9.00 + 3.56 15 — 4 September ... 81.0 73.0 67.1 65.2 90.4 67.6 6.59 + 0 . 8 5 4.77 — 1.68 11 — 6 October ... 82.3 73.6 65.5 63.9 91.4 65.3 5.45 —0.36 26.98 + 1 4 . 1 5 25 + 5 November ... 82.0 72.7 65.6 63.7 90.2 62.9 6.19 + 0 . 5 5 5.42 — 6.12 14 — 5 December ... 79.8 72.0 65.5 64.1 92.5 68.5 5.44 + 0 . 3 0 14.93 + 6.92 19 + 3 82.5 73.6 67.1 65.1 90.0 64.9 6.53 + 0 . 2 0 93.47 . + 4.68 170 —20 MEANlT TOTALS METEOROLOGICAL — 1969 THE TRI UVA STATION, DEBEDDE TEMPERATURE °F SUNSHINE RAINFALL MONTH M ax im um D ry M ax im um W et M in im um D ry M in im um W et M ea n ho ur s pe r da y D iff er en ce fr om a v er a ge (25 yr ) D iff er en ce fr om a v er a ge (25 yr ) D iff er en ce fr om av er ag e (25 yr ) January . . 73.7 69.2 61.3 58.1 5.0 + 1.0 6.5 — 2.7 February . . 75.3 69.4 62.4 57.3 6.0 + 1-4 3.5 — 2.8 March . . 74.5 69.3 61.8 57.7 6.1 + .2 6.7 — 0.4 April . . 79.6 74.7 66.9 63.9 6.0 + 2 .9 12.0 + 1.6 May . . 81.3 74.7 66.8 62.6 4 .0 + -4 2.3 — 3.7 June . . 82.1 72.6 68.9 63.3 5.0 — 2 .6 1.0 — 1.4 July . . 81.4 71.1 65.3 59.9 5.1 — 3 .6 4.6 + 0.5 August . . 79.4 71.8 65.4 61.3 5.0 + 2.8 10.1 + 4.1 September . . 79.9 71.5 64.9 60.3 6 .0 + 1.5 2 .9 — 2.2 October . . 76.2 71.8 66.9 65.5 3 .0 + 0.5 11.2 0 November . . 74.4 70.1 64.8 60.8 3.1 + 2.1 6.5 — 5.1 December . . 72.1 77.5 < 68.1 71.2 62.8 64.9 60.3 60.9 2.1 4 .7 + 1.1 + 0 .6 26.8 94.1 • + 11.4 + 1.3 MEANS TOTALS FIELD EXPERIMENTS, TRIALS AND FACTORY EXPERIMENTS CONDUCTED BY THE TEA RESEARCH INSTITUTE OF CEYLON IN 1969 All field and factory experiments carried out by the TRI in 1969, 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 — Nematology £ — 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 from 1965 to 1968. 200 REFERENCE TO EXPERIMENT NUMBERS IN PART II OF ANNUAL REPORTS SERIES EXPERIMENT NUMBER YEAR A 1 — 10 1965 11 — 13 1966 14 — 16 1967 17 — 22 1968 23 — 30 1969 L A 1 — 17 1965 18 — 32 1966 33 — 34 1967 35 — 36 1968 37 — 38 1969 M A 1 1966 2 — 5 1969 U A 1 1965 2 1966 3 - 7 1969 A Y T 1 — 13 1965 14 — 20 1966 21 — 23 1967 L A Y T 1 — 2 1965 B 1 1965 E 1 — 24 1965 25 — 40 1966 41 — 56 1967 57 — 71 1968 72 — 81 1969 M E 1 1965 2 — 5 1966 6 1967 7 — 9 1969 N 1 — 11 1965 12 - 16 1966 17 — 24 1967 25 — 32 1968 33 — 43 1969 L N 1 1965 2 1966 M N 1 1966 2 1968 U N 1 1966 P 1 — 2 4 1965 25 — 54 1966 55 — 69 1967 70 — 82 1968 83 — 100 1969 L P 1 — 6 1965 U P 1 — 8 1965 9 1966 P H 1 — 19 1965 20 — 29 1967 30 — 35 1969 L P H 1 1965 2 — 3 1966 4 1967 5 1968 M P H 1 1965 U P H 1 — 6 1965 SERIES EXPERIMENT NUMBER YEAR V P 1 — 1 6 1965 17 1966 18 — 21 1967 22 — 24 1968 L V P 1 — 7 1965 8 — 10 1966 11 1969 M V P 1 — 5 1965 6 1966 7 1967 U V P 1 — 7 1965 T 1 — 17 1965 18 — 25 1966 26 — 32 1967 33 — 36 1968 37 — 46 1969 L T 1 — 3 1966 4 — 8 1967 9 — 11 1968 12 1969 M T 1 — 3 1966 4 — 7 1967 8 1969 UT 1 — 3 1966 4 1967 W 1 1965 2 — 10 1966 11 — 14 1968 15 — 16 1969 L W 1 — 5 1965 6 — 8 1966 9 — 18 1967 19 — 28 1968 29 — 33 1969 M W 1 1966 2 — 3 1968 Extension Experiments X A 1 — 5 1965 6 — 8 1966 X L A 1 — 17 1966 18 1968 X M A 1 — 3 1966 X U A 1 — 13 1965 X 14 — 15 1966 X P H 1 — 4 1965 5 — 12 1966 X L P H 1 1965 X M P H 1 — 3 1966 X P 1 — 7 1965 X U P 1 — 2 1965 X E 1 — 8 1967 X L E 1 — 7 1965 201 INDEX TO 1969 EXPERIMENTS This list is complete up to 31.12.69 PAGE 156 A23 — Four clones each at 5 spacings at No. 3 and No. 5 Fields, St Coombs 51 A24 — Three clones each at 3 spacing patterns at No. 5 field, St Coombs 51 A25 — Mukhing and cover crops in young tea 56 A26 — Mulching and cover crops on surface runoff and erosion 56 A27 — Sulphate of ammonia, urea, calcium ammonium nitrate and other treatments on two clones at No. 9 field, St Coombs 38 A28 — Effect of soil pH on growth of tea at Brookside Group, Halgranoya 38 A29 — Urea foliar application and absorption by the tea plant 39 A30 — Induced scorch in nursery plants 40 LA37 — Inter-row crops in young tea 156 LA38 — Diversification of tea land—Observation plots of timber species MA2 — Three periods of rehabilitation, 3 types of rehabilitation crop and 3 types of ground cover during early growth of replanted tea at Mid-Country Station, Kandy 170 MA3 — Clone x spacing x bringing into bearing at Mid-Country Station, Kandy 170 MA4 — NPK, Mg and frequency of application on clonal tea at Ratwatte Estate, Ukwela 170 UA3 — Nitrogen (urea) at 3 levels and 3 methods of application on clonal tea at the Passara Substation, Gonakelle 40 UA4 — Size of hole, level of phosphate and clones 56 UA5 — Mulching forking and level of nitrogen 56 UA6" — NPK, Mg on clonal tea at the Agratenne Substation 49 UA7 — Shade x clone x bringing into bearing at Aislaby Estate, Bandarawela 52 E72 — Heptachlor, heptachlor + plyac at 2 levels, BHC, BHC + JF-2184, BHC + DS-443, endrin, endrin + Plyac, Nicabron, iodfenphos and Padan for shot-hole borer control at Carolina Group, Watawala 116 E73 — Heptachlor 40% EC at 2 levels, heptachlor 20% EC, heptachlor + plyac at 2 levels, heptachlor + JF-2184, heptachlor + DS-4443, heptachlor + Emulgator VA at 2 levels, BHC + Plyac and BHC + JF-2184 for shot-hole borer control at Carolina Group, Watawala 117 E74 — Heptachlor 40% at 2 levels, heptachlor 20% EC, hepta­ chlor + Plyac at 2 levels, heptachlor + JF-2184, heptachlor + DS-4443, heptachlor + Emulgator VA at 2 levels, BHC + Plyac and BHC + JF 2184 for shot- hole borer control at Ury Group, Passara 117 E75 — Heptachlor, heptachlor + Plyac at 2 levels, heptachlor- impregnated jute, BHC, BHC + JF-2184, BHC + DS- 4443, BHC + Plyac, endrin, endrin + Plyac at 2 levels for shot-hole borer control at Ury Group, Passara 117 E76 — Levels of N, P and K on shot-hole borer numbers and damage at Carolina Group, Watawala 117 202 ANNUAL REPORT FOR 1969 203 E77 — Aluminium phosphide (Phostoxin) at 2 levels, ethylene dibromide, trichlorobenzene, dichlorvos at 2 levels, ortho-dichlorobenzene, dibromochloropropane (Fuma­ zone) and dibromochloropropane (Nemagon) for the control of Up-Country Live-Wood Termite (Postelec- trotermes militaris) at Alton Group, Upcot 121 E78 — Three levels of aluminium phosphide (Phostoxin) for the control of Up-Country Termite (Postelectrotermes militaris) at Alton Group, Upcot 121 E79 — Methyl bromide, aluminium phosphide (Phostoxin) at 2 levels, BHC smoke generator at 2 levels, dichlorvos, ethylene dibromide at 2 levels, all applied under poly­ thene cover, aluminium phosphide at 4 levels and BHC granules drilled and inserted into the termite colonies for the control of the Low-Country Live-Wood Termite (Glyptotermes dilatatus) at Talangaha Estate, Nakiyadeniya 121 E80 — Aluminium phosphide (Phostoxin), ethylene dibromide at 4 levels, dichlorvos in kerosine at 4 levels, zinc phosphide at 3 levels, sodium cyanide (Cymag) at 3 levels, para-dichlorobenzene at 4 levels, trichloroben­ zene at 4 levels, BHC granules at 4 levels for the control of the Low-Country Live-Wood Termite (Glyptotermes dilatatus) at Talangaha Estate, Nakiyadeniya 122 E81 — Dichlorvos at 2 levels, ethylene dibromide at 2 levels, para-dichlorobenzene at 2 levels, BHC granules at 2 levels and trichlorobenzene at 2 levels for the control of the Low-Country Live-Wood Termite (Glyptotermes dilatatus) at Talangaha Estate, Nakiyadeniya 122 ME7 — A survey of shot-hole borer infestation in tea 174 ME8 — A search for biochemical basis for shot-hole borer infesta­ tions of tea 174 ME9 — A comparative assessment of insecticidal control vs inherent tolerance of clones to Shot-hole Borer in MVP1 174 N33 — Methyl bromide, Ditrapex (WN12), Ditrapex followed by thatching, DD, DD followed by thatching and re­ habilitation under Mana grass for one year on the rate of re-infestation of young replanted tea at Derryclare Estate, Kotagala 105 N34 — Terracur-P (5 % granules) at one level, Nemacur-P at one level and Nemagon (20% granules) at 3 levels for control of meadow eelworm infestation on young tea at Liyangahawela Estate, Bandarawela 105 N35 — Two levels of N (ammonium sulphate) each tested against 4 levels of K on yield trends of eelworm-infested fields at Bogawana Group, Bogawantalawa 105 N36 — Effect of fumigation of 4 different soils on eelworm infestation and growth of young tea in pots 105 N37 — Comparison of area fumigation with fumigation of plan­ ting holes only, using Ditrapex (one level), ethylene dibromide (2 levels), DD (one level) and Fumazone (2 levels) as preplant treatments for the control of meadow eelworm at Hindagalla Estate, Namunukula 105 N38 — Age of plants and nematode pathogenicity — 2 clones (one susceptible and one resistant) each with 3 age groups—one half of each set inoculated with meadow eel worms and one half kept as controls, in pots 106 84 204 ANNUAL REPORT FOR 1969 N39 — Nemacur-P (10 % granules) at one level, Terracur-P (10 % granules) at 3 levels and Nemagon (20% granules) at 3 levels in two separate sets of treatments, one at plant- ting and the other as post-planting treatment (10 weeks after planting) for the control of meadow eelworm in young tea in pots 106 N40 — Terracur-P (5% granules) at 2 levels, Nemacur-P (10% granules) at 2 levels and Nemagon (20% granules) at 3 levels in planting holes at planting time at Derryclare Estate, Kotagala 106 N41 — Terracur-P (5% granules) at one level, Nemacur-P (10% granules) at one level and Nemagon (20% granules) at 5 levels in planting holes at planting time at St Coombs 108 N42 — Terracur-P (5% granules), Nemacur-P (10% granules) and Nemagon (20% granules) each at 2 levels for the control of meadow eelworm infestation in young clonal tea in bearing at Eildon Hall Estate, Lindula 107 N43 — Four levels of N (ammonium sulphate) each tested against 4 levels of K, on population build-up of meadow eel­ worm and pathogenicity in pots 107 P83 — Uptake of Benlate by tea shoots and young tea plants 81 P84 — Systemic activitiy of Benlate 81 P85 — Effect of 3 levels of nitrogen and potash on Phomopsis cankers in the greenhouse 82 P86 — Control of Poria hypolateritia by soil treatment with chlo­ ropicrin P87 — Effect of soil treatment with five fumigants on the growth of young tea 85 P88 — Fungicides for the control of Blister Blight on seedling tea 86 P89 — "Cutting across vs free growing"—Effect on Phomopsis cankers at Aislaby Estate, Bandarawela 89 P90 — "Cutting across vs free growing"—Effect on disease severity (Phomopsis theae) at the Passara Substation, Gonakelle 90 P91 — Two methods of pruning compared with unpruned— Effect on disease incidence (Phomopsis theae) 90 P92 — Five fungicides for the control of Phomopsis theae on clone KEN 16/3 90 P93 — Control of Phomopsis theae on clone KEN 16/3 by spray­ ing with suspensions of an antagonistic bacterium ^ P94 — Six fungicides for the control of Phomopsis theae on clone DG 39 at Aislaby Estate, Bandarawela 91 P95 — Three fungicides for the control of Phomopsis theae on clone DG 39 at Aislaby Estate, Bandarawela 91 P96 — Six fungicides for the control of Phomopsis theae on clones MT 18 and NAY 3 at Glennanore Estate, Haputale 91 P97 — Three fungicides for the control of Phomopsis theae on clone TRI 2027 at (Alnwick Division) Brookside Estate, Udapussellawa 91 P98 — Effect of 3 levels of shade on Phomopsis incidence on 3 clones 91 P99 — Effects of different methods of killing Grevillea robusta trees on susceptibility to root diseases - 92 ANNUAL REPORT FOR 1969 205 P100 Susceptibility of Grevillea robusta trees treated with Phor- 93 tox to Ustulina deusta PH30 —• Damage to developing buds by salt sprays 66 PH31 — Bud-growth in relation to diameter of pruned branch 66 PH32 — Bud-growth on different clones 67 PH33 — Fertilizer allocation within the pruning cycle 67 PH34 — Vegetative propagation of Hakea saligna 68 PH35 — Rooting of tea cuttings in liquid media 68 LVP11 — Clonal testing at the Low-Country Station, Ratnapura 157 T37 — The effect of spraying a copper fungicidal preparation at 133 different levels, on made tea characteristics T38 — Manufacture properties of teas manured with three types of nitrogen at different levels 133 T39 — Effect of storage of tea in air-tight plastic containers 134 T40 — Comparison of Keegel cone with Rettie cone 134 T41 — Use of cone attachment in an 8-in. rotorvane using clonal leaf 134 T42 — Use of cone attachment in an 8-in. rotorvane using seedling leaf 135 T43 — Manufacture properties of bi-clonal crosses 135 T44 — Variation of total soluble solids of wet and fired dhools with period of fermentation 135 T45 — Green tea 136 T46 — Dry matter content of some clones 136 LT12 — Comparison of orthodox manufacture with mixed ortho- dox-rotorvane 138 MT8 — Tip content of clones 141 W15 — Five chemicals each at 2 levels compared with hand weeding on the yield of seedling tea 59 W16 — Control of Artemisia vulgaris 59 LW29 — Foliar activity of some soil-acting herbicides 159 LW30 — Timing of application of diuron—Large scale observation plots 160 LW31 — Effect of different systems of weeding on growth of young tea 161 LW32 — Effect of frequency of weeding on yield of VP tea 161 LW33 — Effect of frequency of weeding on yield of VP tea 162