In pulses, high temperature is a major limiting factor for yield decline. Tamil Nadu has a rich pulse germplasm with high genetic variability. Hence, the present study was designed to develop a technique to screen genotypes for high temperature tolerance. A rapid screening protocol was developed based on the principle of "acquired tolerance". Adapting this temperature induction response (TIR) technique to pulses, popular varieties of TNAU pulses of blackgram (VBG-07-001, VBG-08-003), redgram (CO-6, VBN-2) and soybean (CO-1, CO-2) were screened for thermotolerance. The challenging lethal temperature was standardized as 50°C for 3 hours at which 90 per cent of the seedling mortality occured. The induction temperature was standardized as 36°C to 40°C at which 48.3 per cent of growth reduction over control was noticed. Blackgram showed higher thermotolerance than other pulses in terms of survival percentage and seedling growth. Blackgram seeds showing contrasting behaviour to temperature stress tolerance namely VBG-07-001(tolerant) and VBG-08-003 (susceptible) were analysed for the accumulation and distribution of starch granules responsible for the grain filling under heat stress.

Field experiment conducted with seed treatment of plant growth regulators indicated that gibberellic acid at 50 ppm is the most effective treatment for bhendi under sodic soil conditions. This treatment recorded the highest germination, seedling establishment.total DMP. harvest index.number of fruits per plant and yield of fruits. Gibberallic acid at 50 ppm recorded the highest vegetable yield of 15.7 t/ha followed by GA 75 ppm with 14.8t/ha. The control recorded only 8.07 t/ha of yield.

Metroglyph analysis was done in a group of 23 genotypes of coconut, Cocos nucifera L. The varieties came under two groups based on morphological characters. Three groups were recognized when the classification was made on the basis of nut cha racters. The exotic cultivars, in general, had relatively higher expression for morpholo gical and nut characters. The possibility of obtaining heterotic hybrids from divergent parental combinations was indicated. MATERIALS AND METHODS Twenty three genotypes of coconut (Cocos nucifera L.) maintained at the Coconut Research Station, Veppankulam, Tamil Nadu, India, formed the materials for the study. The trees in different accessions were in the age group of 24-26 years. The ex periment was raised in a completely randomised design. Among the 23 cultivars, 14 were collected from India and the rest exotic. The exotic types were drawn from Malay sia (three) Philippiness, Java, Siam, Fiji, New Guinea and Vietnam (Cochin China) through Central Plantation Crops Research Institute, Kasaragod, India. Although the number of palms in each genotype varies from 6 to 13, observations were limited to only 4 palms in each genotype which resemble to each other very closely in morphology and nut charac ters, to avoid intra genotypic variation. The mean data over the four palms were subjected to study. Observations were made on six morphological traits viz. plant height, number of functional leaves, girth at collar, length of petiole, length of leaflet bearing portion and the number of leaflets on one side, during 1982 to 1984. For studying the nut components, two nuts of 12 months maturity were collected from each of the four trees at harvest. Data were collected on weight of whole nut, dehusked nut, kernel and copra per nut and kernel thickness for each nut separately by following standard procedures during the summer months (March, April, May, June), The mean data over 96 observations (2 nuts, 4 palms, four months and three years) in each variety were used for the study.

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An investigation was undertaken to study the pattern of sucrose accumulation in five sugarcane varieties especially under delayed harvest. It was evident that maximum sugar accumulation occurred during 12th month irrespective of varieties. In general, the quality declined with advance in age. There was a mean reduction of 3.55% in quality by three months delay in harvest. Among the five varieties studied, sugar sustainability could be seen.in Si 86098 which recorded the highest CCS of 10.57% even at the age of 15th month. The present investigation led to the identification of cane clones for sugar sustainability even under delayed harvest. Such clones can be maintained and utilised for its sugar retention as donor.