黄瓜霜霉病是一种毁灭性病害,在我省普遍发生,危害严重,对生产威胁很大。黄瓜霜霉病是由一种霜霉菌侵入危害而引起的。这种菌从叶片侵入后,夺取黄瓜的养分,使原来鲜嫩碧绿的叶片很快出现黄褐色的多角形的病斑;并从叶子背面长出黑霉来。如条件合适,病情会又快又凶的蔓延起来,只需几天时间,叶片就会枯黄、脱落、全株死亡。大棚黄瓜发病原因:一要有病原菌存在;二要有适合发病的环境条件;三要有感病品 Cucumber downy mildew is a devastating disease, which is common in our province, causing serious harm and threatening the production. Cucumber downy mildew is caused by the intrusion of a downy mildew. After invaded by the leaves, this fungus takes away the nutrients of the cucumbers so that the originally green leaves appear polygamous spots of yellow-brown polygons; and black molds grow from the back of the leaves. If conditions are right, the disease will spread quickly and fiercely, just a few days, the leaves will be yellow, fall off, the whole plant died. Cucumber shedding causes: one to have the presence of pathogens; two have to adapt to the onset of environmental conditions; three to be susceptible