Heat tolerance and bacterial wilt resistance of tomato genotypes in the humid tropics f Kerala .   eline Agricultural he warm humid tropical climate characterized by high day and night temperature and uses the bacterial wilt incited y Ralstonia solanacearum resulting in complete devastation of the crop . Hence, to identify a al site is located at 8 . N latitude and an altitude of 29 . 0 m above MSL .   orty two genotypes collected from different sources (Table 1) were evaluated in a ndomized block design with two replications during June to September (South West onsoon period) .   The mean day and night temperature for the crop period was 29 . C and 23 . C . The rainfall received was 652 . 9 mm spread over 66 days . The land selected for the experiment was a bacterial wilt sick plot wherein a solanaceous crop was cultivated previously .   Observations on fruit set, pollen sterility, yield and bacterial wilt were recorded . The fruit set percentage ranged from 17 . 57 in LE 11 to 70 . 57 in LE 46 . The lowest percentage of pollen sterility was noticed in LE 30 (2 . 31) whereas the line LE 36 recorded the maximum (71 . 25) . The highest yielder LE 34 (1967 . 5 g / plant) recorded high fruit set (65 . 83%) and low pollen sterility (3 . 66%) . High temperature often results in low fruit set due to pollen sterility, stigma elongation and low pollen germination (Rudich, et al . , 1977; Weaver and Timm, 1989) .   The correlation studies revealed significant correlation between fruit set and yield (0 . 5153) whereas the correlation of pollen sterility with fruit set and yield was negative, though not significant ( - 0 . 1394 and - 0 . 1922) . Wessel - Beaver and Scott (1992) reported strong positive correlation between fruit set and yield . As high fruit set ability is controlled by dominant genes (Hanson et . al , 2002), the lines with high fruit set viz . LE 46, LE 38 and LE 34 may be of use in further breeding to obtain a high yielding variety . The results of the observations on bacterial wilt incidence under field conditions revealed that 20 accessions were resistant whereas, four accessions showed 100 per cent bacterial wilt . Screening under artificial epiphytotic condition is essential to confirm the resistance of these 20 accessions . The highest yield was recorded by LE 34 followed by LE 1 and LE 22 . They were also resistant to bacterial wilt . They possessed high fruit set ability and pollen viability and can be considered as the high temperature tolerant accessions suitable for the humid tropics . o C , V . A . , Chandrmony, D . , Gokulapalan, C . and Rajamony, L . Kerala University, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, India . T rainfall leading to high humidity makes it extremely difficult to grow the large fruited fresh market tomatoes in Kerala . This coupled with high soil acidity ca b tomato genotypes suitable for the humid tropics of Kerala, a study was taken up t the Department of Olericulture, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala . The experiment F ra m

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