Abstract
The experiments were carried out to ascertain the effect of day and night temperature on the growth and flower formation of egg-plant.
1. Effect of thermoperiod on the vegetative and reproductive responses
Seedlings were grown at the following seven different thermoperiods:
Experiment Day temperature-Night temperature
I {15°C-10°C20°C-15°C25°C-20°C30°C-25°C
II {17°C-12°C23°C-18°C30°C-25°C
Combination of high temperature treatments induced the vigorous growth followed with the earlier flower bud differentiation, development and the increased number of flowers.
2. Effect of night temperature on the vegetative and reproductive responses
Seedlings were grown at combinations of day temperature 30°C and various different night temperatures. The higher the night temperature up to 25°C, the more vigorous the seedling growth, the earlier the date of flower bud differentiation, and the more the number of flowers. The night temperature higher than 25°C, on the other hand, restricted the seedling growth and retarded the flower bud differentiation, resulting in the increase in the number of leaves to the first flower.
3. Effect of low night temperature at various stages of seedling growth on flowering behaviour
Seedlings were grown at day temperature 30°C and night temperature 25°C, and subjected one, two and three weeks to the low night temperature 12°C and/or 18°C at various stages of seedling growth, and then they were returned to the original condition. During the course of this experiment the day temperature was maintained at 30°C.
It was found that exposure of seedlings to low night temperature for at least two weeks just after cotyledon expansion resulted in the smallest number of leaves to the first flower.
