立枯病是棉花苗期的主要病害,棉花立枯病发生后常导致棉苗成片死亡,发病初期不见棉苗倒下,但实际里面已经不会有新根长出。发病初期为淡褐色,发病大约一周后,逐渐变为黑褐色,有时会在子叶中部形成不规则的棕色斑点,以后病斑破裂而穿孔。发生立枯病后,茎部发生枯萎,棉叶“无神”。幼苗时期容易出现烂种、烂芽的情况。幼苗由黄至枯死症状。 Blight is the main disease in cotton seedling stage. Cotton blight often leads to the death of cotton seedling. No cotton seedling is found in the early stage of the disease, but no new root is actually grown. The initial onset of light brown, about a week after the onset, gradually turned dark brown, sometimes in the cotyledon irregular brown spots formed after the lesion rupture and perforation. After the occurrence of blight, the stem withered, cotton “without God ”. Seedling prone to rotten, rotten bud situation. Seedlings from yellow to dead symptoms.