甘薯根腐病在河南、山东、江苏、安徽、河北、湖北、陕西和湖南省都有发生,但病区范围大,受害严重的,首推河南,其次为山东。据我校1981年调查统计,河南省发病的县市为84个,最高发病面积为140万亩。尽管各省引起重视的时间有早晚,但通过病区调查,大体都是六十年代末至七十年代初发展和猖獗起来的。为什么许多省会同 Root-rot disease of sweet potato occurred in Henan, Shandong, Jiangsu, Anhui, Hebei, Hubei, Shaanxi and Hunan Provinces. However, with a large area of ​​wards and serious victimization, Henan was the most important, followed by Shandong. According to our school survey in 1981, there were 84 counties and cities in Henan Province with the highest incidence of 1.4 million mu. Although the provinces pay more attention to time sooner or later, they are generally developed and rampant through the ward surveys in the late 1960s and early 1970s. Why do so many provinces