葡萄霜霉病在各葡萄产区均有发生,是葡萄的主要病害之一。幼苗感病后,叶片枯焦,新梢生长停滞,枝条不能成熟,如果成株发病引起早期落叶,削弱树势,影响当年和来年的葡萄产量。 症状 主要危害叶片,也能为害新梢、卷须叶柄、幼花序、果柄和幼果。叶片受害在叶片上产生边缘不清晰的水渍状淡黄色小斑,随后渐变淡绿至黄褐色多角形病斑,病斑逐渐形成不规则形斑块。天气潮 Grape downy mildew occurs in all grape producing areas, is one of the major diseases of grapes. Seedling susceptible, the leaves coking, shoot growth stagnation, branches can not mature, if the incidence of adult plants caused by early deciduous, weakening the tree vigor, affecting the current and the following year’s grape production. Symptoms of the main hazards leaves, but also harmful shoots, tendril petiole, inflorescence, stalk and young fruit. Leaf damage caused by the leaves on the edge of the water is not clear water-like light yellow spots, then gradient light green to brown polygonal lesions, lesions gradually formed irregular shaped plaque. The tide of the weather