Understanding green stem in soybeans

Abstract

Green stem is a term used to describe abnormal or delayed senescence maturation patterns in soybean [Glycine max (L.) Merr.] where the stems of affected plants stay green even after pods reach physiological maturity. Green stem has been reported by agronomists throughout the United States, but it is generally more prevalent in the Southern United States. Green stem occurs when nutrient sink strength is weak, which can be associated with environmental stress, insect feeding, and some diseases. There is a genetic component to green stem development, and some varieties are more prone to green stem than others. Management options are somewhat limited, since by the time green stem is observed, most management choices will require delaying harvest, which reduces seed quality. Primary options include waiting to harvest until after a hard frost or using desiccant products prior to harvest.