Classic symptoms of fan leaf virus on Pinot Noir include yellowing leaf discoloration. Washington State grape growers should be on the look out for grape fan leaf virus, a troublesome virus that can affect berry size. Until recently, the disease had not been found in the state. “We were under the impression that we didn’t have the virus here,” said Dr. Naidu Rayapati, Washington State University virologist. But in 2007, scientists detected the disease in four wine grape cultivars in Washington—Pinot Noir, Chardonnay, Cabernet Franc, and Merlot. The disease was identified in different grower vineyards in geographically separated areas in […]