Agronomic Responses of Corn Hybrids to Plant Densities in Central Louisiana.

Increased seed costs make it important to  know if the optimum plant density for corn grain yield differs with hybrid relative maturity.  In 2015 and 2016, studies were conducted to evaluate the agronomic response of three corn hybrids differing in relative maturity at eight different plant densities ranging from 20,000-55,000 plants per acre.  The study was conducted under dryland conditions in a Coushata silt loam.  Experimental design was a factorial arrangement in a randomized complete block with four replications. In conclusion, plant height increased as hybrid relative maturity increased but was not impacted by plant density.  Ear height increased as hybrid relative maturity and plant density increased.  Stalk diameter increased as hybrid relative maturity increased and decreased as plant density increased.  Stalk lodging increased as hybrid relative maturity increased and was not affected by plant density possible due to abundant soil moisture and moderate temperatures during the growing season.  Test weight increased as hybrid relative maturity increased and was not affected by plant density.  As expected, grain moisture increased as hybrid relative maturity increased and there were no differences across the plant densities.  Optimum plant density across hybrids or RM for grain yield and net return was observed at the 32,000 plant density.  The objectives of this study were to characterize the agronomic responses of regionally adapted hybrids of differing relative maturities to plant density and the subsequent impact on corn grain yield and net returns.