Vegetable Crop Update #14
Updates provided by Amanda J. Gevens, Chair, Associate Professor & Extension Specialist, UW-Madison, Dept. of Plant Pathology
In this issue I provide updates on DSVs and PDays for preventative management of late blight and early blight. We have had substantial increases in DSVs over the past few days (since reported in newsletter of July 4) due to heat and moisture. All locations and plantings have surpassed Blitecast threshold of 18 and should be on regular, weekly preventative fungicide programs for late blight management. As for PDays and early blight management, we’ve had consistent accumulations and early and mid-season planting in southern and central WI are at/over threshold and should be receiving preventative treatment for early blight management. In my early blight fungicide trial at UW Hancock Ag Research Station, I noted the first early blight lesions in lower canopies of Russet Burbank and Atlantic cultivars. In north-south oriented rows, the high winds of Mon evening left canopies tipped showing yellowing in lower portions of plants. Aging, declining, stressed, and N-deficient plants are always the first to show early blight.
I also wanted to note that Cole Lubinski of UW Extension Langlade County and the WI Seed Potato Cert Program is coordinating a virtual field day in place of the annual Langlade airport field day. More to come on this, but please note July 23 for this event. The UW potato and vegetable extension/research team will be contributing. Thanks to Cole for coordinating.