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黄瓜霜霉病是黄瓜生产中危害最大的一种病害。发病后传播速度快 ,如防治不及时往往造成大幅度减产 ,给菜农造成巨大的经济损失。笔者通过多年的实践观察 ,分析造成发病的原因主要有以下几点。①定植前温室本身带菌 ;②苗期防治不及时 ,造成定植苗带病 ;③定植密度过大 ,通风透
Cucumber downy mildew is one of the most damaging diseases in cucumber production. After the onset of the spread of fast, such as prevention and control are not often caused by a substantial reduction in output, causing tremendous economic losses to vegetable farmers. The author through years of practice observation, analysis of the causes of the disease are the following main points. ① before planting the greenhouse itself with bacteria; ② seedling prevention and treatment is not timely, resulting in colonization with disease; ③ planting density is too large,