白粉病是温室和温床黄瓜最严重的病害,蔓延甚速,被害的植株生长衰弱,产量显著降低,发病愈早,产量损失愈重。白粉病先在叶片上呈现出一个个白色薄层的斑点,继而叶上面斑点变得愈来愈多,后来在叶的下面也发生,最后当白色的病斑布满整个叶片时,叶子就干枯。这种病菌也可以发展到叶柄和茎上,除了黄瓜 Powdery mildew is the most serious disease of cucumber in greenhouse and hotbed. It spreads very fast. The plants damaged by the disease grow weakly, the yield is significantly reduced, and the earlier the disease is, the heavier the yield is. Powdery mildew first showed a thin layer of white spots on the leaves, and then the leaves become more and more spots on the leaf, and later also occurs under the leaf, and finally when white patches covered the entire leaf, the leaves dry . This germ can also develop into petioles and stems, except cucumbers