The effect of atmospheric humidity on the yield and quality of soya bean

Abstract

Soya bean plants (cv. Lee) were grown at high and low atmospheric humiditiees in controlled environments. A constant level watering system ensured an adequate supply of water at all times. Bean yields decreased at the low humidity as a result of a reduction m pod number and thus bean number, which was only partly compensated by a small increase In bean weight The reduction In pod number was related to floret abortion rather than pod abortion, and was possibly a consequence of reduced photosynthate supply. The level of humidity did not affect the protein or oil content of the seed. The lower humidity also reduced the dry weights of stems and total tops and the number of nodes per plant. The humidity level before or after flowering alone did not affect bean yield, but the humidity from the start of flowering onwards did affect the number of beans per plant. The possible significance of the results for soya bean production In the Australian environment is considered.