北方根结线虫(Meloidogyne hapla Chitwood,1949)在我国华北、华东各省都有分布,对花生、烟草、桑、豆类、蔬菜以及多种花卉苗木造成一定程度的危害,尤以沙质土发生重。国外报导在其发病田进行棉花轮作是降低北方根结线虫群体密度的经济有效办法之一。在棉花上的致病力究竟如何国内尚未见有报导。为此,作者用北方根结线虫一个群体在陆地棉品种徐州142上进行了试验观察 Meloidogyne hapla Chitwood (1949) is distributed in all provinces of North China and East China, and causes a certain degree of harm to peanut, tobacco, mulberry, beans, vegetables and various flower seedlings, especially heavy sandy soil . It is one of the most cost-effective ways to reduce population density of Meloidogyne incognita in foreign reports that cotton rotations occur in its field. How the virulence on cotton has yet to be reported in the country. To this end, the author of a group of northern root-knot nematodes in the cotton varieties of Xuzhou 142 were observed experiment