Genotype by Environment Interaction for Ear Moisture Loss Rate in Corn

Abstract

Corn (Zea mays L.) hybrids with rapid ear moisture loss rate (EMLR) are needed to reduce post-harvest production costs relative to artificial grain drying. Previous investigations indicated that genetic variation for grain dry-down rate exists; however, genotype by environment interaction (GEI) has not been specifically investigated. The objectives of this study were to (i) evaluate GEI for EMLR of selected commercial corn hybrids, and (ii) assess the contribution of known environmental factors to GEI for EMLR. Experiments with two groups of corn hybrids (early maturity and medium and full season maturity) were conducted during 1993 to 1995 at multiple planting dates. Restricted maximum likelihood method was used to estimate GEI variances and interpret the stability for each hybrid. Hybrids of both maturity groups differed significantly in their stability. Precipitation was the single most important environmental factor that contributed to GEI. When two factors were considered simultaneously, precipitation + growing degree days (GDD) from planting to black-layer maturity and relative humidity + GDD from planting to black-layer maturity accounted for the largest amount of GEI. Individual hybrids responded differently to these factors. These results provided insight into the causes and nature of GEI for EMLR and should help reduce or exploit GEI.