棉花轮纹斑病又称棉黑斑病 ,俗称腰折病 ,是一种种子带菌传播的侵染性真菌病害。沿江圩区棉花均能发生。一、发病症状病原侵染子叶、叶片、叶柄和茎。子叶和叶片受害 ,病斑初为褐色近圆形 ,边缘紫红色 ,病斑扩大后生同心环纹及黑色霉层。茎杆受害时 ,在第 1薹果枝与主茎结合部 Cotton leaf spot disease, also known as cotton black spot disease, commonly known as waist fold disease, is a kind of infectious fungus disease spread by seed. Cotton along the polder area can occur. First, the pathogenesis of pathogen infection cotyledons, leaves, petioles and stems. Cotyledon and leaf damage, lesion initially brown almost circular, purple edge, enlarged lesion concentric rings and black mold layer. Stalk damage, in the first stalk branch with the main stem junction