最近，汝州的葱紫斑病发生较普遍，个别地块病株率达５０％以上。现将该病的发生与防治要点提供农户参阅应用。葱紫斑病在苗期、生长期及采种期均可发生，主要危害叶及花梗。病斑多从叶尖或花梗中部开始发生，然后向下部蔓延。开始病斑很小，白色稍凹陷，中央呈淡紫色，以... Recently, the occurrence of Purple Spot disease in Yuzhou is more common. The rate of diseased plants in individual plots is over 50%. Now the occurrence of the disease and prevention and control points to provide farmers refer to the application. Purple onion blight at the seedling stage, growth and seed can occur, the main hazards leaves and pedicels. Lesions and more from the tip of the middle of the pedunculate or pedunculate, and then spread to the lower part. Start small lesions, slightly white depression, the central was purple, with ...