Row Width and Plant Density Effects on Corn Grain Production in the Northern Corn Belt

Abstract

Continued genetic improvement in the ability of hybrid corn (Zea mays L.) to withstand high plant density stress requires agronomists to periodically reassess optimal plant density and row width. Furthermore, the optimal plant density level and row width for corn grain yield may vary with location, primarily latitude, in the Corn Belt. This study was conducted to evaluate corn grain yield, harvest moisture, test weight, and stalk lodging with modern corn hybrids, as affected by row width and plant density in the northern Corn Belt. At six locations in 1998 and 1999, four hybrids differing in relative maturity, ear type, plant height, and leaf orientation were planted at row widths of 76, 56, and 38 cm and five plant density levels ranging from 56000 to 90000 plants ha−1. Plots were arranged randomly in a split‐split plot configuration. Results show that corn grain yield increased 2 and 4% and harvest moisture decreased by a factor of 2.1% when row width was narrowed from 76 cm to 56 cm and 38 cm, respectively. The highest plant density evaluated, 90000 plants ha−1, had the highest grain yield. Grain moisture decreased and grain test weight increases slightly as plant density increased. A hybrid × row width interaction was not observed indicating that hybrids that yield well in conventional 76‐cm row systems will also yield well in narrow row systems.