Updates provided by Amanda J. Gevens, Chair, Associate Professor & Extension Specialist, UW-Madison, Dept. of Plant Pathology and Yi Wang, Assistant Professor & Extension Potato and Vegetable Production Specialist, UW-Madison, Dept. of Horticulture
In this issue we address updates from N trials on potatoes, updates on potato/tomato late blight; potato early blight; and cucurbit downy mildew.
Cucurbit powdery mildew is beginning to show up in southern and central WI on non-cucumber cucurbit types primarily. Page 244 in our A3422 WI Commercial Vegetable Production guide (link below) can help guide fungicide selections. Hot, dry weather can especially exacerbate this disease. In our recent trials programs including quinoyxfen (Quintec) were especially effective at reducing powdery mildew in pumpkin. In WI, we have documented resistance in the pathogen population to myclobutanil (Nova, Rally). https://cdn.shopify.com/s/files/1/0145/8808/4272/files/A3422-2020.pdf