一、葡萄白粉病发病症状:果实受害,先在果粒表面产生一层灰白色粉状霉,擦去白粉,表皮呈现褐色花纹,最后表皮细胞变为暗褐色。叶片受害,在叶表面产生一层灰白色粉质霉,逐渐蔓延到整个叶片,严重时病叶卷缩枯萎。新枝蔓受害,初呈现灰白色小斑,后扩展蔓延使全蔓发病,病蔓由灰白色变成暗灰色,最后黑色。 First, the symptoms of grape powdery milia disease: fruit damage, first in the fruit surface to produce a layer of white powdery mildew, wipe the white powder, the skin showed brown pattern, and finally the epidermal cells into a dark brown. Leaf damage, in the leaf surface to produce a layer of ash white moldy, and gradually spread to the entire leaves, sick leaves in severe shrinkage withered. The new branch vine victims, early grayish white spots, after the expansion of the spread of the whole spread of the disease, the sick vine from gray to dark gray, the last black.