水稻纹枯病又称云纹病,是水稻生产上的一种常发性、普发性病害,水稻苗期至穗期各生育阶段均可发生,一般从分蘖期开始染病,孕穗到抽穗期形成发病高峰,到蜡熟期逐渐停止蔓延。1.症状苗期至穗期都可发病。叶鞘染病在近水面处产生暗绿色水浸状边缘模糊小斑,后渐扩大呈椭圆形或云纹形,中部呈灰绿或灰褐色,湿度低时中部呈淡黄或灰白色,中部组织破坏呈半透明状,边缘暗褐。发病严重时数个病斑融合形成大病斑,呈不规则状云纹斑,常致叶片发黄枯死。叶片染病 Rice sheath blight, also known as moire disease, is a common and generalized disease in rice production. Rice can develop from seedling stage to heading stage. It usually starts from tillering stage and booting stage to heading stage The incidence of the formation of the peak to gradually stop the spread of waxy. 1. Symptoms can be disease to seedling stage. Leaf sheath infection at the water surface at the edge of the dark greenish water-like fuzzy small spots, gradually enlarged oval or cloud-shaped, central gray or brown, low humidity when the middle was pale yellow or gray, central tissue was Translucent, edge dark brown. Serious disease when a few spots merged to form a large lesion, was irregular shaped cloud spots, often caused by yellow leaves withered. Leaf disease