葡萄毛毡病主要为害叶片,也为害嫩梢蔓、花梗及幼果。叶片被害初发病时,叶背出现大量的不规则白色小斑点,后逐渐扩展凹陷,密生很厚的似毛毡状白色绒毛,最后变为茶褐色,且凹陷使叶正面凸起,病斑大小不一,四面常被叶脉限制呈不规则形.发病严重时病叶卷缩、变厚、胞硬,叶面凹凸不? Vitis virens mainly damage leaves, but also damage young shoots, pedicel and young fruit. When the leaves were first attacked, a large number of irregular small white spots appeared on the back of the leaves. After that, the pits gradually expanded and became densely covered with felted white fuzz. Finally, the leaves became dark brown, and the depressions caused the leaves to bulge on the front and the lesion sizes , Surrounded by the veins are often restricted to irregular shape.When the disease is serious sick leaves curling, thickening, hard, foliar irregularity?