黑鞘病(Ophiobolus oryzae Miyake)最初出现在稻株基部的叶鞘上,以后,茎的基部也会感染。在水中的病斑呈黑色圆形或椭圆形,渐渐扩大成不规则的形状,而露出水上的病斑则呈褐色,故又名褐鞘病。后期病斑扩大,病部组织被破坏,菌丝侵入组织内部,产生子囊壳,并借此越冬。黑鞘病的发生与灌水的深度有关,如湖南衡南县三塘乡湖南省劳模陆秀宾的互助组,保持浅水灌溉的 Ophiobolus oryzae Miyake first appeared on the leaf sheath at the base of the rice plant and later the base of the stem was also infected. In the water lesions were black round or oval, gradually expanded into an irregular shape, and exposed spots on the water was brown, it is also known as brown sheath disease. Lesions later stage of expansion, the diseased tissue is destroyed, mycelium invades the tissue, resulting in ascus shell, and to wintering. The incidence of black sheath disease and the depth of irrigation, such as Hunan County, Hunan Province Santan Xiang Lu Xiu-bing, Hunan Province, the mutual aid group to maintain shallow irrigation