棉花黄萎病是影响棉花产量的主要病害。通过对病株率达95.6％,死苗率达47.1％的17.4亩试验地进行调查,发现早打顶、留叶枝可显著地减轻棉花黄萎病害。 1.打顶及其早晚与黄萎病发生的关系7月24日调查正常打顶的604株(12个果枝)平均发病为2.49级,早打顶的302个相邻株(少于10个果枝)发病为0.64级,正常打顶比早打顶病重3.89倍。在2—10个果枝范围内打顶越早病害越轻,相关系数r=0.8638。 Verticillium wilt is the main disease affecting cotton yield. Through the survey of 17.4 mu of diseased plants with rate of 95.6% and dead seedling rate of 47.1%, it was found that early topping and retained leaf shoots could significantly reduce the disease of cotton verticillium wilt. 1. Topping and its relationship with the occurrence of early and late Verticillium wilt On July 24, the average incidence of 604 strains (12 fruiting branches) in the normal topping survey was 2.49 and 302 adjacent strains (less than 10 Fruiting branches) incidence of 0.64, normal topping more than 3.89 times earlier than the top disease. In the range of 2-10 fruit branches, the earlier the disease, the lighter the correlation coefficient r = 0.8638.