Kate Everts, Vegetable Pathologist, University of Delaware and University of Maryland; keverts@umd.edu
Late blight has been confirmed on tomatoes in Montgomery County, MD. This is the first positive late blight in Maryland this year. We have sent the sample for strain identification, and do not have that information, yet. Late blight was also confirmed on tomatoes on June 20 on the Eastern Shore of VA.
Delaware growers should continue preventative applications of chlorothalonil, Gavel or mancozeb. Scout the potato and tomato crops aggressively and contact Extension personnel for confirmation of suspect late blight.