1987年以甘薯品种宁12-17为试材,进行了薯块取样部位对干率影响的研究。收获时取100株的薯块,每株选中等薯2～4块,用两种方法进行:①将50株的薯块,按长度等分成头、尾两部分,②将另50株的薯块,按长度等分成头、中、尾三部分,然后分别测定各部分干率(干率=干重/鲜重×100%),通过各部分干率再求出整薯块的真实干率。采用①法的,首先求出111块甘薯头、尾的干率与整薯块干率的相关系数,分别为0.71, In 1987, Ning 12-17, a sweet potato variety, was used to study the effect of sampling area on the rate of drying. At the time of harvesting, 100 strains of potato tuber were harvested, and 2 to 4 tubers of each potato were selected. Two methods were used: ① 50 potato tubers were divided into two parts according to length, Block, according to the length is divided into three parts, head and tail, and then were measured in each part of the dry rate (dry rate = dry weight / fresh weight × 100%), . The use of ① method, the first to find 111 sweet potato head and tail of the rate of dry matter and the correlation coefficient of bulk potato, respectively, 0.71,