Department of Plant, Soil and Microbial Sciences Cropping Systems Agronomy

Shorter growing season experienced in the northern Corn Belt requires the use of hybrids with early relative maturity (RM) compared to hybrids used in the Central and Southern Corn belt. Previous research has shown that early-RM hybrids had lower grain yield but also low moisture at harvest compared to mid- and late-RM hybrids. However, net returns under early-RM hybrids is often only slightly lower than late-RM hybrids, when both grain yield and moisture content in grain at harvest are considered, due to additional costs for grain drying in late-RM hybrids. Additionally, risk of frost and mycotoxin contamination increases with delayed harvest, more common in mid- to late-season hybrids. Overall, selecting corn hybrids with appropriate RM range is one of the most important management decisions growers in Michigan and other northern Corn Belt states have to make. In this study, annual grain yield and moisture at harvest data in three zones across Michigan from 2011-2017 were obtained from the Michigan Corn Performance Trials. Hybrids were classified into early- or late-RM based on their RM ratings. Relative net returns were calculated using corn grain price for a given year and drying costs ranging from $0.03-0.05/bu/point. Grain yield was higher in late-RM hybrids than the early-RM hybrids only in nine out of 21 zone-years. Grain moisture was consistently higher in late-RM across all zone-year combinations. Consequently, net returns in late-RM hybrids was higher only in six but lower in nine (at $0.03/bu/point) out of 21 zone-years compared to early-RM hybrids. Results from this study indicated the benefit of selecting early-RM hybrids compared to the late-RM hybrids in terms of net returns in addition to low perceived risk of frost damage and mycotoxin contamination.