棉花红叶枯病是棉花中后期的主要病害之一,在主要棉区经常普遍或局部发生,遇上旱涝年份危害程度超过其他棉花病害。我国主要棉区五六十年代发生这病害比较普遍,以后随着棉田基本建设水平的提高,肥水条件逐渐改善,病情逐年减轻以至基本不再发生。近年有些地方由于棉田有机肥施用 Cotton leaf blight is one of the most important diseases in the middle and later stages of cotton. It occurs frequently or locally in major cotton areas, and is more endangered than other cotton diseases in the years of drought and flood. In the 1950s and 1960s, the disease was common in the major cotton areas in our country. With the improvement of the capital construction of cotton fields, the condition of fertilizer and water was gradually improved and the disease gradually reduced and basically no longer occurred. In some places in recent years due to the application of organic fertilizer in cotton