白菜白斑病广泛发生于我国南北方 ,除为害白菜外 ,还为害十字花科的许多其他种 ,如甘蓝、油菜、菜薹、花椰菜、萝卜、芥菜、芜菁、小青菜、乌塌菜等 ,是一种分布广、寄主多的病害。主要为害寄主叶片 ,在叶上产生斑点 ,影响光合作用 ,从而降低产量。1　症状最先在叶片出现灰褐色 White cabbage white spot occurs widely in our country’s north and south, in addition to cabbage damage, but also harmful to many other species of the cruciferous, such as cabbage, rape, Cai Cao, cauliflower, radish, mustard, turnip, Is a wide distribution, the host of many diseases. The main damage to host leaves, leaves on the spots, affecting photosynthesis, thereby reducing production. 1 Symptoms The first to appear grayish brown in the leaves