The Effect of Light on the Growth of Soybean Seedlings

ABSTRACT- During the course of 13 days of germination and growth, the dry weights of roots, hypocotyl, and epicotyl increased in soybeans grown both in the light and in the· dark. The roots of etiolated 13-day-old soybeans were only 50 per cent of the weights of roots from similar plants grown in the light. The epicotyls of etiolated plants were only 18 per cent of the dry weight of epicotyls of light-grown plants, but the hypocoyl weights of etiolated plants were greater than those grown in the light. Cotyledon dry weight of light-grown plants was reduced by 70 per cent during the 13-day period while the cotyledon weight of the etiolated plants was reduced only 60 per cent. Cotyledon removal materially reduced the subsequent growth of soybean seedlings