甘薯是我省第二大粮食作物，常年种植２６万ｈｍ２左右，而病毒病的发生为害，会引起甘薯品种种性严重退化，品质变劣，减产２０％以上。因此，江苏、山东等省相继开展了甘薯脱毒技术研究，并大力推广应用脱毒甘薯，一般增产２０％～４０％，高的可成倍增长。另据报道，为害甘 Sweet potato is the second largest food crop in our province. The annual planting is about 260,000 hm2. However, the occurrence of virus disease will cause serious degeneration and deterioration of sweet potato variety, with a yield reduction of more than 20%. Therefore, Jiangsu, Shandong and other provinces have conducted research on sweet potato detoxification technology, and vigorously promote the use of virus-free sweet potato, the general increase of 20% to 40%, high can be doubled. According to another report, as sweet