Crop modeling approaches that combine environmental parameters, management, and maize hybrid properties have been described to predict genotype by environment interactions. Plant breeders have the potential to be greatly supported by crop growth models. However, large-scale application of crop modeling in plant breeding is limited by labor and cost required to measure cultivar-specific crop model parameters. The use of crop models in plant breeding has primarily been for identifying and improving physiological traits. Typically, calibrations in these studies are based on only a subset of genetic coefficients needed to fully parameterize a crop model. Our objectives were to determine which parameters differentiate 15 hybrids created by crossing publicly available ex-PVP lines, determine if differences in traits of interest can be accurately simulated from a limited set of parameters, and evaluate the amount and type of observed phenotypic data required to make an adequate hybrid calibration. In this experiment, the APSIM (Agricultural Production Systems sIMulator) maize model v.7.10 was calibrated for 15 hybrids grown widely throughout the Genomes To Fields Initiative. Model calibrations revealed differences among hybrids for 15 genetic coefficients and substantial differences in traits including yield, biomass accumulation, partitioning, and nitrogen uptake. Sensitivity analyses for traits of interest were performed by running 20-year simulations and varying 22 maize crop parameters one factor at a time. In terms of yield, crop development parameters accounted for 52% of the sensitivity, while 28% was attributed to crop growth parameters and 20% to grain component parameters. Our results demonstrate that hybrid performance differences can be simulated using crop growth models and that a large portion of performance variation can be simulated with a subset of parameters. However, our results also demonstrate that phenology parameters alone could only account for just over half of the variation in yield performance differences among these hybrids.
