在伟大领袖毛主席革命路线指引下,我们来到河北省定兴县固城公社国兴大队进行开门办学,深入三大革命实践,学习贫下中农的丰富经验。了解到甘薯黑斑病是威胁甘薯生产的重要病害,为了很好地防治这种病害并发挥化学防治在综合防治中的作用,我们工农兵学员和贫下中农、技术员、革命教师一起,用几种内吸杀菌剂对防治甘薯黑斑病做了试验,初步取得了较明显的效果。在甘薯育苗时,伏薯前用50％多菌灵或50％“7313”,均以2000倍液分别浸种薯10分钟 Guided by the great leader Chairman Mao’s revolutionary line, we came to Guoxing Brigade, Gucheng Commune, Dingxing County, Hebei Province, to open our doors to learn more about the experiences of the poor and the middle peasants in deepening the three revolutionary practices. It is learned that black spot disease of sweet potato is an important disease threatening the production of sweet potato. In order to prevent this disease well and play the role of chemical control in comprehensive prevention and control, our workers, peasants and soldiers are working with poor middle peasants, technicians and revolutionary teachers in several Internal fungicide prevention and control of sweet potato black spot made a trial, the initial achieved a more significant effect. Seedlings in the sweet potato, sweet potato before the use of 50% carbendazim or 50% “7313”, were 2000 times immersed potato seed solution for 10 minutes