THE EFFECT OF SHORT PERIODS OF HIGH TEMPERATURE DURING DAY AND NIGHT PERIODS ON PEA YIELDS

Abstract

Karr, E. J. (Ohio State U., Columbus), A. J. Linck, and C. A. Swanson. The effect of short periods of high temperature during day and night periods on pea yields. Amer. Jour. Bot. 46(2) : 91‐93. Illus. 1959.—The effect of high temperatures during periods of relatively short duration (3‐4 days) at various stages following anthesis at the first bloom node was studied in relation to yield of peas at this node. Except for the periods of differential temperature treatments, the plants were maintained in a standard environment room (24°C., light, 12 hr.; 15°C., darkness, 12 hr.). Three different temperature regimes during the treatment periods were studied: high day temperature—standard night temperature (32°—15°C.) ; standard day temperature—high night temperature (24°—30°C.) ; and high day and night temperatures combined (32°—30°C.). The data reveal the existence of a relatively well‐defined thermal‐sensitive period, with maximal sensitivity to high day temperatures occurring at about 9‐11 days from full bloom, and maximal sensitivity to high night temperatures occurring about 6‐9 days from full bloom. High night temperatures proved more critical, resulting in a maximal reduction of 25% in yield, as opposed to about 8% for high day temperatures. The effect of high day and night temperatures combined tended to be roughly additive.