Notes on Esca Disease on Some Grapevine Varieties Grown in Turkish Thrace

Grapevine production reaches 65,000 tons annually in the 7,000 ha viticultural area in Tekirdag, the main production province of the Thrace region. More than 50 varieties are grown in the district, although very few are dominant. During the surveys that have been done to determine the main phytopathological problems in vineyards, sudden death of the plants and diffuse necrosis on the leaves were observed. The most common symptoms of esca were chlorotic, light-green, irregularly diffused foliar spots which later became yellow-brown or reddish and finally turned necrotic. These areas were surrounded by a narrow dark red border. Internal symptoms of the disease were observed as rotted tissues extending downward and upward along the trunk. Many grapevine varieties were affected drastically, a few had very mild symptoms of esca and no decline. The Cardinal, Semillon, Yapincak and Kozak Siyahi varieties were severely affected.