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1.连作:由于大豆病菌多属土壤习居菌,可在土壤中腐生,病菌滋生良好,繁殖快,从而土壤中菌源数量增多,发病重。因此,连作年限越长,发病越重。2.土壤温、湿度:大豆种子发芽至幼苗生长适宜温度为20℃～25℃,温度低于9℃出苗就受到严重影响。因此播种期土壤温度低,发病重。土壤含水量大,特别是低洼潮湿地,大豆幼苗长势
1. Continuous cropping: As soybean germs are mostly soil habitat bacteria, can be saprophytic in the soil, germs breed well, rapid propagation, so that the number of soil bacteria increased, the incidence of severe. Therefore, the longer the continuous operation, the more severe the disease. 2. Soil temperature and humidity: soybean seed germination to seedling growth suitable temperature is 20 ℃ ~ 25 ℃, the temperature is lower than 9 ℃ emergence is seriously affected. Therefore, sowing soil temperature is low, severe onset. Soil moisture content, especially low-lying wetlands, soybean seedlings growing