Tropical and subtropical vegetables (2+1)

Unfruitfulness

• Temperature particularly a night temperature has profound effect on fruit setting in tomato. High day temperature (above 320C) and high night temperature (above 200C) is not congenial to fruit set. On the other hand fruits normally fail to set at or below 130 C. Both high and low temperature adversely affects fruit set mainly by reducing pollen viability and pollen germination on stigma. For this reason, low fruit set is a problem during summer cultivation in eastern India, especially in West Bengal where temperature remains above critical limit and during winter cultivation in northern India where temperature falls far below the critical level in winter.

Control
1) Growing high temperature tolerant varieties like HS-102, Punjab Kesar, Punjab Chuhara, Hot set etc.
2) Growing low temperature tolerant varieties like Pusa Sheetal, Cold set, Ostenkinskiz etc.
3) Application of growth substances like parachlorophenoxy acetic acid (PCPA) 50 ppm at full bloom stage or 2,4 D, 1-2 ppm prior to anthesis.