韭菜疫病是由于夏季高温多雨,在高湿条件下韭菜生产的主要病害,从苗期到移栽后大田生长期均可发病,若防治不当会造成韭菜大面积死亡,严重减产。根据近几年的实践,单用化学农药防治效果不佳,应采用综合防治效果较好。一、危害症状根、茎、叶、花薹等部位均可受害,尤以假茎和鳞茎受害最重。叶片、花薹感病多从下部开始,初呈暗绿色水浸状病斑,当病斑蔓延扩展到叶片的一半左右,全叶变黄、下垂、软腐,潮湿时,病部 Leek blight is due to the hot and humid summer, the main disease in the production of chives under high humidity conditions, from seedling to transplanting field growth can be disease, if not properly controlled will cause a large area of ​​leek deaths, a serious cut. According to the practice in recent years, the effect of chemical pesticides alone is not good, so the comprehensive prevention and cure effect should be better. First, the harm symptoms Roots, stems, leaves, flower stalks and other parts can be harmed, especially the heaviest damage to the stems and bulbs. Leaves, flower sprouts and more susceptible from the bottom of the beginning, the beginning was dark green spot disease, when the spread of lesions spread to about half of the leaves, the whole leaves turn yellow, drooping, soft rot, damp,