Genetic gain of Dekalb brand maize hybrids released during the first two decades of this century in the United States 95–115 relative maturity markets

Abstract Era studies are key to estimate the historic rate of genetic gain for commercial traits of a crop. We evaluated for the first time nearly all maize hybrids released (269) in five relative maturity markets (95, 100, 105, 110, and 115) from Bayer Crop Science Dekalb brand over the last 20 years. We focused on grain yield, plant height, moisture, and test weight. We then compared the predicted gains derived from the genome‐wide prediction models with the estimated ones. We found that genetic gain was positive and significant for grain yield across the five relative maturities, ranging from 0.077 to 0.147 Mg ha −1 year −1 , while it was negative (desirable) and significant for plant height, with a decrease from −0.259 to −0.456 cm year −1 . We did not find significant changes for grain harvest moisture and test weight. The genetic gain estimates were consistent with predictions using the company's genomic estimated breeding values. We concluded that breeding has delivered increased yield and decreased plant height over this period for Dekalb hybrids, and the company's genomewide prediction model can be used to predict the direction of future maize genetic gains. This era study includes a larger number of hybrids, broadens the range of relative maturities, and incorporates comparisons with genomewide predictions compared to previous era studies.