Sweet potato tops new crop option?

Apr 16, 2004 12:00 PM, By Carol Sanders

Its nutritional content is comparable to spinach. It can be harvested several times a year. You can eat these greens as well as its highly nutritious root. Arkansas soil and climate are conducive to growing it.

What is the “new” kind of greens? Sweet potato tops or leaves. They are readily served as a cooked vegetable in many parts of the world and are rich in vitamin B, iron, calcium, zinc and protein.

Walter Tucker, an 80-year-old World War II Bataan survivor who received his Purple Heart 59 years later, recalled that prisoners were not fed much and survived on fish heads, rice and sweet potato tops.

Although Arkansas soil and climate are favorable for sweet potato production, Arkansas growers cannot compete economically with major producer states such as North Carolina, Louisiana and Mississippi.

“But sweet potatoes could become a profitable, leafy vegetable crop in Arkansas if appropriate varieties were available or could be developed,” says Shahidul Islam, researcher, Department of Agriculture at the University of Arkansas at Pine Bluff (UAPB).

With a grant from the USDA Cooperative State Research, Education and Extension Service (CSREES), Islam and Mohammed Jalaluddin, UAPB agronomy professor, are researching the cultural conditions, environmental stress, physiological and biochemical functions of specialty vegetables, herbs and medicinal plants with the emphasis on human health and nutrition.

In the meantime, Steve Izekor, UAPB Extension horticulturist and researcher, O. A. Porter, UAPB professor of agronomy; and A. V. Corley, UAPB research assistant, have been collecting information on yield and performance of commercially available varieties and advanced breeding lines when grown in Arkansas.

Planting varieties with higher yields and superior market grades may offset the rising production costs, encourage the conversion of more acreage to sweet potatoes and enable Arkansas growers to successfully compete with neighboring growers.

UAPB scientists discovered that the highest yield of U.S. No. 1s was 420 bushels per acre at Marianna, Ark., for advanced breeding lines 94-96. The state average yield of No. 1s is 198 bushels per acre.

Besides the possibility of becoming a lucrative cash crop for small farmers, sweet potato tops are excellent sources of antioxidative compounds, mainly polyphenolics, which may protect the human body from oxidative stress that is associated with many diseases including cancer and cardiovascular diseases, says Jalaluddin. Sweet potato greens have the highest content of total polyphenolics among other commercial vegetables studied.

Sweet potatoes contain protein, dietary fiber, lipid, and essential minerals and nutrients such as calcium, phosphorus, magnesium, sodium, potassium, sulfur, iron, copper, zinc, manganese, aluminum and boron. Sweet potatoes are also important sources of vitamin A, thiamin, riboflavin, niacin and ascorbic acid.

Izekor, Porter, and Corley are including white flesh varieties in their research as these varieties are sold in Asian markets and to the evolving sweet potato chip industry.

“There are many uses for sweet potatoes other than a food crop,” says Islam. Sweet potatoes are an important raw material in the production of starch, sugar and alcohol.

The Toyota Motor Company is planning to use the waste from the production of raw materials as a source of energy. And, in cooperation with Mitsui & Co., Toyota is planning to produce biodegradable plastics from sweet potatoes in the near future.

Growers wanting more information about the sweet potato research mentioned in this article can get all the details in the Arkansas Agriculture and Rural Development, the research journal of the UAPB School of Agriculture, Fisheries and Human Sciences available from Dr. Robert Katayama, editor, Mail Slot 4913, UAPB, Pine Bluff, Ark. 71601. Or, call 870-575-7245 or email katayama_r@uapb.edu.