随着转基因抗虫棉的推广,棉花枯、黄萎病和红叶茎枯病呈现出逐年加重蔓延扩大的趋势,成为新形势下影响棉花优质高产高效的主要因素,据调查,2004年以来大荔县连续3年发病面积每年都在0.8万公顷以上,占全县植棉总面积的35%左右,全县年平均减产皮棉105kg.hm-2,三年累计损失皮棉1.6 With the promotion of transgenic Bt cotton, cotton withered, Verticillium wilt and red stem blight showed a tendency to increase and spread year by year, becoming a major factor affecting cotton’s high yield and high quality under the new situation. According to the survey, since 2004, County incidence area for three consecutive years in more than 8000 hectares, accounting for 35% of the county’s total area of ​​cotton, the county average annual reduction of lint 105kg.hm-2, total loss of three years lint 1.6