我国各棉区棉枯、黄萎病发展迅速。一般在棉田初发病株的地方,往往成为日后的发病中心,由此扩散蔓延,由零星病田发展为重病田。当前零星病田在全国还占有相当大的比重,而病田面积的扩大,主要是零星病田的增多。零星病田土壤中菌量积累尚 Cotton fields in our country cotton, Verticillium wilt developed rapidly. Generally in the early onset of cotton plant in the place, often become the future center of disease, which spread of spread, from sporadic disease to severe disease. The current sporadic disease field in the country also occupies a large proportion, while the expansion of disease area, mainly sporadic disease field increases. Sporadic disease soil accumulation of bacteria in the soil yet