Defoliation Effects on Different Corn (Zea mays, L.) Hybrids as Influenced by Plant Population and Stage of Development1

Abstract

The effects of 50 and 100% defoliation at different stages of development of early, midseason, and late maturing corn hybrids grown at three plant populations were studied in a field experiment. The relative reduction in grain yield due to defoliation was different for hybrids, stages of development when defoliated, and degrees of defoliation, but was not influenced by differences in plant population density. Loss in grain yield due to defoliation was associated primarily with a reduced rate of dry matter accumulation in the grain during grain formation.