Yield Contribution of Apical and Subapical Ears in Prolific and Nonprolific Corn

Previous studies have demonstrated higher corn (Zea mays L.) yield potential for prolific corn hyhrids (more than one ear) compared to nonprolific hybrids (one ear). However, little is known about the relative contribution of the second ear to total yield at various N levels. This study compared yield responses to N rates of 56, 140, and 224 kg N ha −1 of prolific Hybrids A (1202 x Mo17) and B (I117 x B73) with responses of nonprolific Hybrid C (Pioneer 3320) at a uniform low plant population density. All three hybrids gave a positive yield response to N applications. The prolific hybrids increased both in apical ear weight and in subapical ear weight and number in response to N rate. Averaged over N rates, Hybrid A yielded 24% and Hybrid C 14% higher than Hybrid B in 1987 [...]