Controlling Powdery Mildew of Pumpkin Using Pre-existing Fungicide Scheduling Programs

Abstract

Powdery mildew is a serious disease of pumpkin throughout the Northeastern United States. Control of pumpkin powdery mildew is currently achieved through the use of a calendar-based application of fungicides. Three non-pumpkin weather-based fungicide scheduling programs for powdery mildew were evaluated to determine their usefulness in the control of cucurbit powdery mildew using fewer appropriately timed fungicide applications. None of the weather-based fungicide scheduling programs provided a benefit in fungicide scheduling compared to the calendar-based fungicide application scheduling when evaluated with historical weather and disease initiation data. The weather-based fungicide scheduling programs function primarily by determining conditions that are not suitable for the proliferation of powdery mildew. New York State experiences favorable conditions for the growth of powdery mildew throughout the cucurbit growing season in most years, therefore reducing the utility of the weather-based fungicide scheduling programs in this region.