棉花黑斑病,也叫轮纹病,我国各棉区均有发生,北方棉区重于南方棉区,可危害棉花的根、茎、叶和幼铃,棉苗发病严重时,造成大面积死苗。近几年随着我国转基因抗虫棉面积的增加,黑斑病逐年加重。一、发病症状(表1)表1棉花黑斑病发病症状 Cotton black spot disease, also known as ring rot disease, all cotton areas in our country have occurred, the northern cotton area is heavier than the southern cotton area, can endanger the cotton roots, stems, leaves and young bell, cotton seedlings severe onset, resulting in large area Dead seedlings. In recent years, with the increase of the area of ​​transgenic cotton in our country, the incidence of black spot is increasing year by year. First, the incidence of symptoms (Table 1) Table 1 symptoms of cotton black spot disease