Corn (Zea maize L.) Height in a Mid-South Production System, and Breeding Implications.

Corn breeders focus primarily on yield. Consistent yield drives sales. Secondary and tertiary breeding objectives are yield followed by yield, respectively. This is fine up to a point. For instance, disease may limit productivity of particularly susceptible hybrids or predators may feed on the ears of hybrids that lack trait packages to protect against insect feeding with proteins expressed in the husk and ear tissues. Common planting densities for both rainfed and irrigated production result in one ear per plant. To get more ears, and the subsequent boost in yield, producers increase population. As population increases, more fertility inputs are needed to maintain plant productivity, but specifically to maintain stalk thickness, strength, and integrity. While ears may get slightly smaller as populations increase, particularly with ear length, that is an economic vs. agronomic question that is not entirely off-putting to producers. Conversely, with lodging, that becomes a potentially catastrophic question answered by drones, aerial imagery, and insurance agents. To continue to improve yields by planting more plants per unit area we need to examine shorter plants with stiffer stalks. Stine and Dekalb have hybrids that have been evaluated in a high population production system. Plant heights, ear heights, lodging and breeding opportunities observed over the past two growing seasons will be presented.