棉茎枯病(AscochytagossypiiSyd.)在湖北省江汉平原近20年未大面积发生。2004年6月在江汉平原的潜江、天门、荆州、仙桃等地区发生,面积达0郾3万hm2。该病于6月上旬棉花现蕾初期开始发病,先在棉茎的第2果枝部位出现暗褐色长形溃疡,病斑逐渐扩大成梭形,中央凹陷,淡褐色,周围紫红 Cotton stem blight (AscochytagossypiiSyd.) In Jianghan Plain in Hubei Province in the past 20 years did not occur on a large area. June 2004 in the Jianghan Plain Qianjiang, Tianmen, Jingzhou, Xiantao and other areas occurred, an area of ​​0 郾 30,000 hm2. The disease began in early June cotton bud early onset, first in the second branch of cotton stem dark brown ulcer occurred, the lesion gradually expanded into a fusiform, central depression, light brown, around the purple