大厂县棉田,自1967年发现零星棉枯、黄萎病后,很快蔓延扩展,病情逐年严重。1979年开展普查,并采取综合防治措施;现在基本上控制了病害,皮棉单产有所回升。 (一) 为了找出这两种病在我县发生的原因和蔓延扩散的途径。我们从调查着手,研究我县棉花枯、黄萎病发生原因: 一、重茬棉田多,耕作粗放,使发病率 Dachang County Cotton Field, since 1967 found sporadic cotton wilt, Verticillium wilt, soon spread and spread, the condition is serious year by year. In 1979, the census was carried out and integrated prevention and control measures were taken. Now the diseases are basically controlled and the lint yield rebounds. (A) In order to find out the causes of these two diseases in our county and ways of spreading and spreading. We start from the investigation to study the county cotton withered, Verticillium wilt causes: First, crop stubble and more extensive farming, so that the incidence