Comparisons of Corn (Zea mays L.) Inbreds and Hybrids Grown at Equal Leaf Area Index, Light Penetration, and Population1

Abstract

Previous yield comparisons between inbred lines and hybrids in corn (Zea mays L.) were generally based upon a common plant density. Hybrids may exhibit a competitive advantage over the inbreds due to their superior size and leaf area. In this study the size differences were eliminated by growing a commercial double-cross corn hybrid, the two parental single crosses, and their inbred parents at populations that resulted in a common population, a common LAI, and a common percent light penetration value. At the same plant population the single crosses were superior to their respective inbred parents in: (i) vegetative yield; (ii) grain yield; (iii) rate of grain dry ter accumulation; (iv) length of the grain-filling period; (v) number of kernels per hectare; and (vi) final kernel weigbt. At equal LAI and percent light penetration the inbreds equaled their respective single cross progenies in total vegetative yield and number of kernels per hectare. The hybrids were superior to their inbred parents for the other components studied. The percentage of soluble solids in the stalks was greater in the inbreds, which may have been an effect of the slower rate of grain filling. Copyright © . .