Widely cultivated plants that produce edible starchy tubers.
Sweet potatoes (Ipomoea batatas) are related to morning glories, while ordinary potatoes (Solanum tuberosum) are members of the nightshade family, as are peppers and tomatoes. Both types of potatoes have their origin in South or Central America. Sweet potatoes, more commonly cultivated in warm or tropical climates, serve as an important source of calories in Africa, Asia, and Latin America. Ordinary potatoes have been a staple of European consumption since their introduction by Spanish explorers, who discovered them in South America, where they had been cultivated for centuries. They were introduced to North America and many other countries by European explorers and today are an important food throughout the world. According to the Centro Internacional de la Papa, potatoes are the fourth-most important food crop in the world (after wheat, maize, and rice) and sweet potatoes are the seventh (barley and cassava are fifth and sixth, respectively). Developing countries account for about 95 percent of global sweet potato production, while Europe and North America produce over 60 percent of the ordinary potato crop.
Sweet potatoes are more commonly cultivated in warm or tropical climates, serving as an important source of calories in Africa, Asia, and Latin America. Pictured here are two members of the Kitahara Youth Association with a pile of sweet potatoes in Okinawa, Japan. (Library of Congress)
Neither type of potato is widely traded. From a total production of about 139 million metric tons of sweet potatoes in 2000, less than 100,000 metric tons were exported. In the same year, total potato production was 328 million metric tons, and less than 6 percent of this production was exported. Although potatoes can be stored for relatively long periods, they are perishable and must be stored in cool, dry conditions. Because they grow well in most parts of the world, there is little economic incentive to incur the cost of shipping them under the necessary storage conditions. French fried potatoes can be found virtually everywhere, but fast-food chains have found it preferable to export their cooking methods and management practices, relying on local sources for potatoes and other ingredients. Most potatoes and sweet potatoes are consumed fresh, although processing and industrial uses (starch) have increased in recent years. About 14 percent of potatoes and 45 percent of sweet potatoes are fed to livestock.
Potatoes are also associated with one of the greatest social catastrophes of the nineteenth century: the Irish potato famine. Peasant farmers in Ireland had come to depend almost entirely on their household potato production for food. When blight destroyed the potato crop in 1845 and 1846, millions of people perished from starvation and many more emigrated from Ireland to North America. Sweet potatoes have never been as popular in European and North American diets as the ordinary potato, but they are at the heart of many of the subsistence systems found in places such as New Guinea, where pig husbandry and horticultural production of sweet potatoes and other root crops provide the main sources of calories.
E. Wesley F. Peterson
See also: Food and Diet.
Centro Internacional de la Papa. “About Potato” (www.cipotato.org/potato/potato.htm, accessed September 2002).
———. “About Sweet Potato” (www.cipotato.org/sweetpotato.sweetpotato.htm, accessed September 2002).
Food and Agriculture Organization of the United Nations. “FAOSTAT: Agricultural Data” (http://apps.fao.org/page/collections?subset=agriculture/, accessed September 2002).