Hybrid-Maize (www.hybridmaize.unl.edu) is a computer program that simulates the growth and yield of a corn crop under non-limiting or water-limited (rainfed or irrigated) conditions. Although the model has no nitrogen component yet, it can contribute important information for fine-tuning N management decisions: (i) quantifying yield potential as the basis for setting realistic yield goals to be used in prescribing total N rates and (ii) in-season prediction of growth and yield potential to down- or upward adjust late-season N applications. In the current season prediction mode, the software allows real-time assessment of corn growth up to the current date based on actual weather data, followed by prediction of growth and final yield thereafter based on historical weather data for the remainder of the growing season. Model validation using data from different sites in Nebraska indicates that final yield predictions became accurate shortly after silking, but relative deviations from normal growth were detected earlier in both irrigated and rainfed environments.