黄瓜霜霉病俗称“跑马干”，是棚栽黄瓜中发生较为普遍且危害最严重的病害之一。此病发病率高，传播速度快，如条件适宜，10天左右就可使瓜秧枯黄，严重影响黄瓜的产量。一、危害症状黄瓜霜霉病主要危害叶片。子叶染病后，正面初呈褪绿，继而黄化，最后产生不规则的枯黄斑。在潮? Cucumber downy mildew, commonly known as “Happy Horse ”, shed greenhouse cucumber is one of the more common and most harmful diseases. The incidence of the disease is high, the speed of transmission, such as the appropriate conditions, about 10 days can make melon seedlings yellow, seriously affecting the yield of cucumber. First, the harm symptoms Cucumber downy mildew main hazards leaves. After the cotyledon disease, positive early chlorotic, and then yellow, and finally produce irregular dry yellow spots. In the tide?