Researchers from the University of Florida Institute of Food and Agricultural Sciences are looking at sweet potato vines as a source of biofuel feedstock and livestock feed. The vines are typically thrown out during harvest while the roots could serve as a source for biofuels. Post-doctoral researcher Wendy Mussoline said this could be a key finding for Florida’s ag industry and the biofuels industry at large. The research was published in the Journal of the Science of Food and Agriculture.

UF/IFAS researchers have found a sweet potato variety, CX1, that outperformed two table varieties in field tests. They think CX1 potatoes may serve well as feed for livestock and as biofuel.

“The agriculture industry in Florida is looking to find new, viable crops to replace the citrus groves that have been diminished by the greening disease,” Mussoline said. “Potato farmers are also trying to find new crops that offer both biofuel alternatives as well as food and/or animal feed opportunities. They are conducting field trials on several varieties of sweet potatoes to determine if they are an economically viable crop that they can market.”

According to a newly published study by professor Ann Wilkie and Mussoline, an industrial sweet potato variety (CX-1) may do the trick. Today 99 percent of the ethanol produced in the U.S. comes from corn or sorghum, according to the study. But scientists and business interests are considering highly productive alternatives such as sweet potatoes for biofuel. Although China produces 81 percent of the world’s sweet potatoes, U.S. sweet potato production reached a record high of 3.2 billion pounds in 2014, according to the U.S. Department of Agriculture (USDA).

Wilkie and Mussoline found that CX-1 is a superior choice as a dual-purpose crop than the so-called “table” varieties – which people would normally eat — known as Beauregard and Hernandez. They determined this by putting the three varieties through multiple tests in the field and laboratory in Gainesville, Florida. The results found that the CX-1 roots have higher starch content and thus higher potential for fuel ethanol yields than the table varieties.

The study demonstrated CX-1’s value as animal feed and promotes the industrial sweet potato crop as a dual-purpose crop that could be used for both fuel ethanol — from the starchy roots — and nutritious animal feed — from the vines. Although the use of sweet potatoes in the U.S. would be new, it’s already being used as a feedstock in China and Brazil.

“The sweet potato is a high-yielding crop suited to tropical and subtropical climates that requires minimal fertilization and irrigation, and the CX-1 industrial cultivar offers superior potential for feed and fuel,” concluded Wilkie.