THE EFFECTS OF LOW TEMPERATURES ON FRUIT SET OF TOMATOES

This study was conducted between 1990 and 1992 with the aim of investigating the effects of low temperatures on fruit set and yield of tomatoes, cvs. Dario F1 and Amfora F1 in the unheated glasshouse in winter growing period. The investigators focused their attentions especially on the effects of low temperatures on the number of flowers per cluster, the ratio of fruit set, fresh fruit weight, number of seeds per fruit, the difference between anther tube and pistil length, pollen count and viability. The embryonic development during the first ten days after pollination was also observed.

It has been established that low temperatures reduce pollen count and viability thus negatively affecting the fruit set and yield of tomatoes. Differences of results are also noted between Dario F1 and Amfora F1. The minimum temperature below which a degeneration of pollen starts in flowers is 10°C for Dario F1 and 5°C for Amfora F1.