【摘要】 棉花枯萎病在北京市郊区当日平均温度20℃时,棉田开始发病,24—28℃时,发病最烈,低于24℃或高于28℃时,病势减轻。相对湿度在80%以上,发病严重。棉花从苗期到吐絮期均能受其侵染为害,以蕾期受害最重,发病率达20.9—60.6%。防治棉花枯萎病应采取以种植抗病品种为主的综合防治措施。1973—74年,鉴定出陕721品种属高抗类型,蕾期发病率2.5—8.9%,病情指数31.5—35.4;药剂防治采用杀线虫剂滴滴混剂和杀菌剂多菌灵按10:2作土壤处理,蕾期防效可达85.2—100%,比单施杀菌剂或杀线虫剂防效提高20—30%,与小麦、玉米、水稻轮作3—4年,病害可减轻95%以上,病叶、病秆经高温(煮沸后再煮半小时以上)处理,病菌能被杀死。经处理的病叶喂猪,猪粪不带菌。无病土育苗移栽,发病率21.4%,直播棉田发病率63.3%。更多还原

【Abstract】 The incidence of the cotton wilt in-the vicinity of Beijing(Peking)generally reached 10—30% and in ceratin cases upto 50%.In fieldobservations it was found that the disease began to appear when theaverage temperature rose to 20℃,reached its peak at about 24℃and began to decrease when the temperature rose above 28℃。Thecotton plants were infected throughout the growth period,however,the most abundant disease development occurred in the time of ballformation.When the infested soil was in presence of an unidentifiednematode,the disease incidence was significantly increased.In thefield plot where only Fusarium culture was inoculated,the percentageof diseased plants was 51.5%.However,when both Fusaium cultureand nematodes were inoculated,the percentage of infection was increa-sed upto 65.6%.It was determined that the cotton variety Shaan 721was highly resistant to the Fusarium wilt with disease indices 0.6—4.8while the susceptible control variety Xuzhou 1818 showed disease indi-ces 31.5—35.4.The infested soil after being treated with nematcidesin mixture with fungicides resulted the most satisfactory control.Apractice of 3—4 years crop rotation of cotton with wheat,corn orpaddy rice reduced the disease incidence nearly by 95%.更多还原