Aug 31, 2016Florida potato growers explore sweet potatoes
Back in the 1920s, Danny Johns’ great grandfather was the first farmer in the Hastings area to use a tractor instead of a mule. Now, in a region known for producing potatoes for the potato chip industry, Johns, like his ancestor, isn’t afraid of trying something new.
As of this year, Johns is one of a few commercial farmers in Florida who are growing sweet potatoes, a crop not produced in the state since the sweet potato weevil devastated much of the Florida industry for the commercial, orange sweet type in the 1980s. Now, with the help of the University of Florida Institute of Food and Agricultural Sciences, growers like Johns have the opportunity to diversify their business with this reemerging crop.
In Florida, potatoes grown for the potato chip industry, or “chipping” potatoes, are planted in January or February and harvested in May or June, said Scott Chambers, farm supervisor at the UF/IFAS Hastings Agricultural Extension Center. Table stock potatoes, potatoes sold fresh, are also planted and harvested at these times.
Sweet potatoes, on the other hand, are planted in spring, after the growing season for chipping and table stock potatoes is over. “The local growers wanted to increase their land productivity and income by growing sweet potatoes when they are not growing chipping or table stock potatoes,” said Guodong “David” Liu, assistant professor of horticulture and Extension specialist.
There are no current UF/IFAS nutrient recommendations for sweet potatoes grown on the Hastings area soil, Liu said, so he and his team are testing how various nutrient regimens affect the quality of sweet potatoes grown in the region.
The data they collect will help sweet potato growers find the most suitable varieties for the area and grow the crop efficiently, Liu said.
UF/IFAS faculty also want to make sure that the economically important sweet potato weevil doesn’t impact these new ventures. Once a week, Bonnie Wells, agricultural crops agent at UF/IFAS Extension St. Johns County, visits each farm to walk the sweet potato fields, examining leaves and roots for signs of damage, and checking traps for captured pests.
“So far, there’s been no evidence of sweet potato weevils at any of the farms we’ve worked with,” she said. “We want to keep it that way.”
Because of Florida’s climate, growers can plant sweet potatoes earlier than those in other states, Chambers explained. This means Florida sweet potatoes could arrive earlier to market and fetch higher prices, he said.
However, Florida growers can’t take advantage of this marketing window — yet.
Sweet potato plants start off as “slips,” young plants raised commercially that are eventually transplanted into fields. Right now, Florida growers rely on slips produced in other southeastern states, which aren’t available during Florida’s early planting season.
Growing slips in Florida is the solution, said Chambers. UF/IFAS researchers have successfully raised slips in greenhouses at the UF/IFAS Hastings Agricultural Extension Center, and their methods may one day help growers produce their own slips, he said.
David Dinkins, a UF/IFAS Extension multi-county agent who specializes in sustainable agriculture, along with Janice Bohac, a former U.S. Department of Agriculture sweet potato geneticist and breeder consulting on the project, are working to identify possible markets for Florida sweet potatoes.
Bohac is helping UF/IFAS researchers explore more unusual sweet potato varieties, for example, a purple-fleshed variety that is high in antioxidants, the starchy boniato, a popular staple in Caribbean cuisine similar to the ‘Japanese Yam’ variety favored by Asian Americans, and a starchy yellow-fleshed type similar to the ‘Hannah Gold’ and the ‘Jersey Yellow’ varieties.
“These specialized varieties can be much more profitable than the more familiar and sweeter orange-fleshed type,” Bohac said. Bohac has provided UF/IFAS researchers with plants from her private breeding program to use in trials.
So far, markets for Florida sweet potatoes look promising, said Dinkins.
“Sweet potatoes have the potential to be a sustainable, alternative crop for tri-county producers for a variety of reasons,” Dinkins said. “Farming sweet potatoes is similar to farming other crops in the area, but requires relatively less water and nutrients. Initial market analysis indicates an increased demand both domestically and internationally. Sweet potatoes also have a great nutrition profile, and they can be processed into popular products such as sweet potato fries.”
— photo: Danielle Johns