黄瓜霜霉病在苗期成株都可受害,是一种世界性病害。我国各地均有发生,在适宜的发病条件下,流行速度快,一两周内即可使叶片枯死,减产高达30%~50%,有的地块因此病为害只采1~2次瓜后就提早拉秧,菜农称之为“跑马干”和“干叶子”。发病原因:引起黄瓜霜霉病的致病菌是鞭毛菌亚门专性寄生菌真菌古巴 Cucumber downy mildew can be affected by adult plants at seedling stage, which is a worldwide disease. In all parts of China, under the appropriate disease conditions, the epidemic is rapid, and the leaves can be withered in a week or two with a yield reduction of up to 30% -50%. Some of the plots therefore suffer only from 1 to 2 melons Raize early seedlings, vegetable farmers called “Happy Valley” and “dried leaves”. The cause of the disease: causing cucumber downy mildew pathogenic bacteria is flagellin Subfamily parasitic fungi Cuba