1995年，大名县北峰赵贵友引进试种甘薯优种52－7。当年试种1．7亩，其中0．7亩春种（6月6日移栽）亩产高达6836公斤；一亩夏栽，第二季甘薯（7月20月移栽）亩产4428公斤．对照复薯亩产仅1386公斤。据调查：52－7甘薯早熟性突出，早发性强，抗病性强，一年可种两茬，故而效益好 In 1995, Damei North Peak Zhao Guiyou introduced sweet potato varieties 52-7. In the same year, 1.7 mu of cultivated land was planted, of which 0.7 mu was planted in Spring (June 6 transplanting), with a yield of 6,836 kg per mu; a mu of summer plantation and a second-season sweet potato (transplanting in July 20) . Control of mu potato yield only 1386 kg. According to the survey: 52-7 sweet potato precocious prominence, early onset strong disease resistance, can be planted two crops a year, it is effective