一、葡萄霜霉病的产生葡萄霜霉病是由真菌中的一种霜霉菌引起的,病菌主要以卵孢子在病组织内或随病叶残留于土壤中越冬,来年在适宜的环境条件下产生游动孢子,借风雨传播引起发病。葡萄得病最明显的特征就是叶背面出现霜状霉层,并且叶片、嫩梢、果柄等出现褐色病斑,使葡萄的器官组织遭到破坏,阻碍其正常的生长发育。葡萄霜霉病多在7月开始发生,7月中、下旬发病渐多,8～9月份为发病盛期。但在5～6月份低温多雨的气候环境,于6月中旬也可发病。游动孢子萌发温度为12～30℃,最适温度为18～24℃,并且萌发和侵染 First, the grape downy mildew grape downy mildew is caused by a fungus in the mold downy mildew, the main pathogen in the disease or oocysts in the disease leaves remain in the soil overwintering, the following year in the appropriate environmental conditions Zoospores produce, spread by the rain caused the disease. The most obvious feature of grape diseases is the emergence of frost-like mildew on the back of leaves, and brown spots appear on leaves, tender shoots and stalks, which damage the organ tissues of grape and hinder their normal growth and development. Grape downy mildew and more in July began to occur, in July, late onset more, 8 to September for the peak incidence. However, in June and June low temperature and rainy climate, in mid-June can also be disease. Zoospore germination temperature is 12 ~ 30 ℃, the optimum temperature is 18 ~ 24 ℃, and germination and infection