Physiological maturity of soybean seeds

Abstract

Maturation of soybean (Glycine max (L.) Merrill) seeds of ‘Bragg' and ‘UFV-1' cultivars was studied. Plant development and seed maturation were studied in randomized blocks field experiments planted in 1977 and 1978. Beginning of flowering and fruiting were dated when the plots had five to ten plants per square meter with one flower or one fruit raceme, respectively. The seeds were harvested seven times each year; after each harvest, the following data were obtained: moisture content, dry weight, tegument and hilum color (Munsell system), germination and vigor of seeds. The absence of yellow-green seeds with homocrome hilum and the loss of green color from the pods represent useful and acceptable indicators of physiological maturity. Maximum soybean seed dry weight was found to be insufficient by itself to characterize physiological maturity.