ABSTRACT
Sweet potato [Ipomoea batatas (L.) Lam.] ranks seventh in annual production among the food crops in the world (1). The cultivation area of this plant species is localized mainly at low lati-tudes of South America, South Asia, and South Africa and spreads as far as some regions of Europe and the United States. The ancient civilization area of sweet potato was tropical America, and at the end of the 14th century it was transported to the Old World. In Japan, the sweet potato was introduced from China to Kagoshima in the Kyushu area at the beginning of the 17th century, by way of Ryukyu Islands, then rapidly spread to Honshu. A famous savant in the Edo era, Konyo Aoki (1698-1769), made an effort to propagate sweet potato. Today, it is called Kara-imo (Chinese potato) or Ryukyu-imo (Ryukyu potato) in Kyushu, and Satsuma-imo (Kagoshima potato) in Honshu (2).
