黄瓜白粉病是露地栽培及保护地栽培黄瓜较常见的病害,全国各地都有发生。其危害严重时,黄瓜叶片逐渐干枯,病害在短时间内迅速流行。为此,搞好黄瓜白粉病的预防预报工作,为及时防治该病提供依据乃是当务之急。一、症状与病源发病初期叶片正面或背面产生白色圆形的小粉斑。以后逐渐扩大成边缘不明显的连片白粉斑,严重时整 Cucumber powdery mildew is a common disease of cultivated cucumber in open field cultivation and protected areas throughout the country. Its serious harm, the cucumber leaves gradually dry, rapid rapid spread of disease in a short period of time. To this end, do a good job in the prevention and control of cucumber powdery mildew in order to provide a basis for the timely prevention and treatment of the disease is imperative. First, the symptoms and pathogenesis of the early leaves of the front or back of a white round small spot. After the gradual expansion into the edge is not obvious contiguous white powder spots, severe whole