因黄瓜具有喜温、耐湿和耐光的特点 ,所以适合于大棚栽培。但由于整个生长期都处在高温高湿的条件下 ,故病害发生较严重。常见有以下几种 :1 .霜霉病　成株发病主要在开花结果期。发病初期叶上出现水渍状浅绿色斑点 ,扩大后受叶脉限制呈多角形的黄褐色 ,潮湿条件下叶背部病斑下 Because cucumber has a warm, wet and light-resistant characteristics, so suitable for greenhouse cultivation. However, due to the high temperature and humidity throughout the growing period of the conditions, so the disease occurred more serious. Common are the following: 1. Downy mildew adult disease occurs mainly in the flowering period. Waterlogging-like light green spots appear on the leaves at the early onset of the disease, expanding to a polygonal yellowish brown under the restriction of the veins. In wet conditions, the back of the leaves is diseased