疫霉菌引起的大豆根部与茎部腐烂病1948年首次发现于美国印第安纳州的东北部,1951年发现于俄亥俄州的西南部。1955年首次发表了该病的报道。疫菌的腐烂病仅在美国和加拿大有所报道。对于感病的大豆品种这种病是很具有毁灭性的。它能造成严重缺株,并使产量减少50％以上。损失的程度因土壤类型、降雨量、耕作方法和品种而异。疫霉引起的腐烂病在低洼、 Soybean root and stem rot caused by Phytophthora infestans was first discovered in northeastern Indiana in 1948 and was found in southwestern Ohio in 1951. The first report of the disease was published in 1955. Diseases of diseased bacteria are only reported in the United States and Canada. The disease is very devastating for susceptible soybean varieties. It can cause serious strain loss and reduce production by more than 50%. The extent of the loss varies according to the type of soil, rainfall, farming methods and varieties. Phytophthora cause rot disease in low-lying,