The sweet potato is said to be one of the most typical Okinawan agricultural products. It is believed that Noguni Sokan brought it back to the Ryukyus from China in 1605 and his lord, Gima Shinjo, studied the methods of cultivation and spread it throughout the Ryukyus. The Ryukyu Archipelago is known for frequently suffering through famines brought on by natural disasters such as typhoons. The advent of a crop like the sweet potato was revolutionary in the Ryukyus because of its ability to withstand the changeable climate. Later the sweet potato spread from the Ryukyus to Satsuma and was introduced to the whole of Japan by Aoki Konyo. In Japanese it is called the Satsuma-Imo or Satsuma potato and was named after the domain in southern Kyushu.
Another one of the typical Okinawan farm products is sugar cane. The time at which the Satsuma-Imo was imported from Ryukyu is unknown, however it is believed that Gima Shinjo, who introduced the sweet potato, dispatched retainers to China to learn sugar manufacturing methods in 1623. The government of the Ryukyu Kingdom soon realized that sugar cane could be traded at a high price in Japan, similar to the profits the Ryukyus received by its monopoly on sales of turmeric. A sugar magistrate was established in 1662 to exercise control over cultivation and sugar manufacture.
