OPTIMUM SOWING DATE IN RELATION TO FLOWER DROP REDUCTION IN TOMATO

In Iran, peak summer temperatures are very high reaching more than 37°C day/ 21 °C night, causing excessive flower drop. This trial was conducted for a period of 3 years in 1984–86, to find out whether sowing dates (age of transplants) and cultivars could have an influence in the reduction of flower drop in tomatoes. Fruit-setting rates before the onset of heat were higher than during the onset of heat. Among the age of transplants and among cultivars, fruit-setting rates were highly significant before the onset of heat, on the other hand, during the onset of heat, no significant difference were observed among the age of transplants and among cultivars. Mean yield per plant showed no significant difference among the age of transplants and among cultivars. In this experiment, sowing dates did not show any significant effect on flower drop reduction of some tomato cultivars.