Effect of High Temperature on Fruit Set in Tomato Cultivars and Selected Germplasm

Selected F 3 and F 4 lines of different origin were evaluated at high temperature (26° night and 35°C day) in the greenhouse along with several known heat-sensitive and heat-tolerant tomato ( Lycopersicon esculentum Mill.) cultivars. A number of the selected lines had fruit set comparable to the tolerant cultivars Saladette, Ohio 7663, BL 6807, and Chico III. The expected greater fruit set of the tolerant cultivars vs. that of the sensitive cultivars was observed. High fruit set in this study was not associated with high seed number in the majority of tolerant cultivars evaluated.