Sweet potato is a vegetable with large, fleshy, edible roots. Historians believe that people first grew sweet potatoes in South America. Today, farmers grow them throughout the world, and they are an important food in many countries. China produces a majority of the world’s sweet potato crop. In the United States, sweet potatoes are sometimes called yams. However, yams belong to a different family (see Yam ).
Sweet potatoes contain high amounts of carbohydrates and vitamins A and C. People buy them fresh, canned, frozen, or dehydrated (dried by removing the water). Sweet potatoes are also used for animal feed, alcohol, and starch. People sometimes eat the leaves of the sweet potato plant, especially in Asian countries. The American scientist George Washington Carver created 118 products and numerous recipes from the sweet potato.
The flesh and skin of sweet potatoes vary in color from purple to white. The most common flesh colors are orange, yellow, and white. Some sweet potatoes, such as the Porto Rico and Jewel varieties, have moist flesh. Others, including the Jersey and Triumph varieties, have dry flesh.
Farmers commonly grow sweet potato plants from roots placed in moist, warm, sandy soil or sawdust in greenhouses or hotbeds about four to six weeks before planting time. The roots produce sprouts called slips. The farmers cuts the slips from the roots and transplants them to fields. There, the slips are generally placed 12 to 15 inches (30 to 38 centimeters) from one another in rows 3 to 4 feet (91 to 120 centimeters) apart. In tropical regions, farmers grow the plants from vine cuttings rather than from slips.
In tropical areas where frost is not a problem, sweet potatoes may remain in the soil for as long as 7 to 12 months. In colder regions, however, growers harvest sweet potato crops in the early fall, before the first killing frost. Immediately after harvesting, the potatoes are cured (partially dried) and stored at temperatures from 55 to 60 °F (13 to 16 °C). Curing and storing the potatoes increases their sugar content and helps keep them in good condition for marketing during the winter and spring.
