Duration of the Grain Filling Period and Its Relation to Grain Yield in Corn, <i>Zea mays</i> L.¹

Abstract

A Significant linear relationship was found among several corn ( Zea mays L.) hybrids grown in 1966 and 1967 at Guelph, Ontario at several planting densities, between grain yield and effective filling period duration. Effective filling period duration (EFPD) is defined as final grain yield divided by the average rate of grain dry weight accumulation during the linear period of grain formation, and hence, is a relative measure of the length of the grain filling period. In each year yield differences among hybrids were more closely related to EFPD differences than to differences in the rate of ear dry weight accumulation. EFPD was unaffected by planting density. Results suggest that significant potential exists in corn for higher grain yields through a genetic extension of the length of the grain filling period.