Air and soil temp have a great influence on the development and flowering of the pepper plant. The time interval between emergence and flowering increases as temp drop. Plants which grew under low temp in any particular growth stage developed an equal or greater number of leaves before the first flower than did plants growing under high temp, regardless of day length.
A soil temp of 10°C retarded plant development, whereas 17°C allowed normal development. The rate of growth increased as soil temp rose. The total plant wt after 100 days of growth under various soil temp increased with rising temp. The top continued to develop with rising temp, but root development was retarded at a soil temp of 30°C or above.