Developing a Management Program for Powdery Mildew in Winter Squashes with Resistant Varieties

Powdery mildew an important disease of winter squash and other cucurbit crops. It occurs throughout New York every year. Management is needed to avoid a reduction in yield. Application of fungicides has been the main practice. Several winter squash varieties with resistance to powdery mildew are now commercially available. Growers need to know how well these resistant varieties perform compared to horticulturally-similar, fungicide-treated susceptible varieties, and whether there are benefits to an integrated program with minimal fungicide inputs. Two experiments were conducted to evaluate acorn and butternut squashes. Growing varieties with resistance to powdery mildew was shown to be an effective and economic means to manage powdery mildew