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棉花茎枯病(Ascochyta gossypii Sadow)在上海地区时有发生。通过研究认为:棉花茎枯病能在多种培养基质上生长,对pH值的选择范围比较广。以pH6.8～7.8最适.菌落在含有少量(0.1％左右)盐份的培养基上生长最好。器孢子发芽需要有少量糖分等碳源,发芽最适温度是19—22.5℃,病菌生长最适温度是20.5～22℃。在海岛棉米—10品种上进行人工接种以23℃最适。潜育期仅24小时,发病也最重。另外,在适宜的条件下,海岛棉的潜育期比岱字棉短1天;棉株有伤比无伤的短1～2天。棉花茎枯病的初侵染以土壤中病残体带菌为主。再侵染由器孢子随风、雨传播造成。发病条件与气温、湿度、降雨量关系密切,与栽培条件也有关系。药剂筛选的结果,为认百菌清、托布津、福美双等对棉花茎枯病的防治效果较好。文中还对棉花茎枯病与蚕豆褐斑病(Ascochyta pisi Lib Var.fabae Spra-gue.)的关系进行了讨论。
Cotton stem blight (Ascochyta gossypii Sadow) occurs in Shanghai. According to the research, cotton stem blight can grow on a variety of culture substrates and has a wide range of pH values. The best pH value of 6.8 ~ 7.8 colonies in the medium containing a small amount of salt (0.1%) on the best growth. Need spore germination need a small amount of sugar carbon source, the optimum temperature is 19-22.5 ℃ germination, bacterial growth optimum temperature is 20.5 ~ 22 ℃. On the island cotton-10 varieties were inoculated with 23 ℃ optimum. Potential incubation period of only 24 hours, the incidence of the most serious. In addition, under suitable conditions, the potential period of island cotton is 1 day shorter than that of Dai cotton. The cotton plants have 1 to 2 days shorter wounds than those without injury. The initial infection of cotton stem blight is mainly carried by the disease in the soil. Re-invasion of spores by the wind, rain spread caused. Incidence conditions and temperature, humidity, rainfall is closely related to the cultivation conditions are also related. Pharmacological screening results for the recognition Chlorothalonil, Topaz, Familia double on the control of cotton stem blight is better. The relationship between cotton stem blight and Ascochyta pisi Lib Var. Fabae Spra-gue. Was also discussed.