据多年调查,鲁西南棉区,一般年份烂铃率在10%～20%;重发生年份,烂铃率高达30%以上,减产20%左右。棉花的烂铃,直接影响着产量的提高和品质的改善。造成棉花烂铃的原因很多,除品种特性和栽培因素外,还有病虫危害,铃期气象因素等等。特别是秋季多雨年份,高产棉田,行距窄,密度大,棉花发育早,棉田封行早,通风透光差,土壤湿度大,棉铃受病菌侵染而引起大量烂铃。其预防对策和应急措施如下。一是整修好排灌渠道。在棉花开花前及时中耕培土,使棉行变埂,行间成沟,灌能进,排能出,雨过田干不积水,降低棉田湿度,既防旱、防涝、防渍;又能预防棉田土壤过湿,可以减轻烂铃。二是肥水条件较好的高产棉田,除适当控制氮肥的施用量,避免棉株发生旺长外,还要注意适当放宽行距,降低密度,尽量推迟封行时间,改善棉田通风透光条件, According to years of investigation, in the southwestern part of Shandong Province, the rate of rotten bolls in the general year is between 10% and 20%; in the year of heavy occurrence, the rate of rotten bolls is as high as over 30% and the yield is reduced by 20%. The bad cotton boll directly affects the improvement of yield and quality. There are many reasons for cotton boll bolls, in addition to breed characteristics and cultivation factors, but also pests and diseases, bell weather factors and so on. Especially in the rainy autumn months, high-yield cotton fields have narrow row spacing, large density, early cotton development, early cotton seal, poor ventilation and soil moisture, and large amount of rotten bolls caused by cotton bolls infested by germs. The prevention measures and emergency measures are as follows. First, renovation irrigation and drainage channels. Cotton cultivation in time before the tillage, so that the cotton line change 埂, between the line into a ditch, irrigation can enter, discharge can be out of the rain field dry without water, reducing the cotton field moisture, both drought, waterlogging, anti-stain; Cotton field can prevent over-wet, can reduce the bad bell. Second, high-yielding cotton fields with better water and fertilizer conditions should not only control the application amount of nitrogen fertilizer but also prevent the cotton plants from growing prosperously, but also pay attention to appropriately relaxing the row spacing, reducing the density, trying to postpone the sealing time and improving the ventilation and light-