GENCALC: Software to Facilitate the Use of Crop Models for Analyzing Field Experiments

Abstract A number of crop simulation models use as model inputs certain coefficients that account for differences among cultivars. These coefficients, often referred to as genotype coefficients, allow the models to simulate performance of diverse genotypes under different soil, weather, and management conditions. The models therefore can potentially be used to resolve the genotype × environment interaction into underlying coefficients. GENCALC (Genotype Coefficient Calculator) is a software package that facilitates the calculation of these coefficients for use in existing crop models. In GENCALC, the coefficients for a genotype are estimated iteratively by running the appropriate crop model with model input data and approximate coefficients, comparing the model output with actual data, and then altering the coefficients until the simulated and measured values match. The coefficients are determined in a specified sequence, starting with those that relate to developmental aspects. GENCALC also allows for calculation of averages (±SD) for the coefficients determined from specific experiments. This facilitates the selection of coefficients with the lowest variability, which can then be stored in crop‐specific database files. GENCALC comprises several programs and requires additional models and model input files, so a hard disk with =2 Mb free space is required. GENCALC will run on any IBM or IBM‐compatible computer with DOS version 3.0 or later.