Late blight of potato and tomato is one of the most serious and dramatic of plant diseases. The pandemic on tomatoes in 2009 throughout the Northeast was a reminder that this disease can still erupt to cause severe damage to tomatoes and potatoes. The Cornell Decision Support System (DSS) is a web-based tool that aids growers to avoid calamity caused by this disease. The DSS integrates effects of weather, host resistance, pathogen presence, pathogen characteristics and fungicide to enable effective and low pesticide suppression of this disease. The enhancements developed as result of this IPM grant were: i) to expand the number of fungicides available in the DSS; ii) to modify recommendations based on the increased number of fungicides. The enhancements and modifications were demonstrated to be effective in a field experiment. Thus, the DSS is now a more useful tool in the constant struggle against this severe disease.