Genetic variety in soybean heat stress responses is poorly understood, and the logistical difficulties of heat stressing plants in a controlled experiment outdoors limits conventional breeding strategies for improving heat stress tolerance. In this project, we are using predictive modeling to link molecular markers with improved heat stress responses in a variety of soybean genotypes. The project is using data generated in growth chamber experiments as well as heated, open-air field plots. We have measured differences in heat stress response among soybean genotypes grown in the field, and these data will help us identify molecular markers that can be used in soybean breeding.