Phomopsis Cane & Leaf Spot

Abstract

Phomopsis cane and leaf spot, once known as “dead arm,” is a common disease in most regions of the world where viticulture is practiced. Severely infected leaves are misshapen, yellow, and fall from the vine prematurely. Infected rachises are brittle so that portions of the cluster may fall off before harvest. Infected fruit are discolored and can drop to the ground before maturity. When incidence of the disease is high, crop losses of 10 to 40 percent can occur.