COLUMBIA — Sumter farmer Bonita Clemons snapped a six-inch tender okra pod right off the plant from the Clemson University Sandhill Research and Education Center (REC).

“We only grow them this long,” Clemons said, holding her fingers about three inches apart, “because as they get bigger they just get hard. Now I have a new okra to grow.”

Powell Smith, far right, shows tomato plants to attendees of the Sustainable Tomato Field Demonstration at the Sandhill Research and Education Center.

Powell Smith, far right, shows tomato plants to attendees of the Sustainable Tomato Field Demonstration at the Sandhill Research and Education Center.
Image Credit: Scott Miller/Clemson University

Clemons was among the attendees of the Sustainable Tomato Field Demonstration Thursday at the Sandhill REC in Columbia. For the demonstration, Clemson Extension agent Powell Smith planted several tomato varieties at the Sandhill research farm, including grafted tomatoes, under various growing conditions to show farmers what could be the most profitable for them. His work is part of a growing agricultural research program at the Sandhill REC.

The okra variety, which Smith described as the “queen of okra varieties,” is an heirloom collected decades ago from a Georgetown County plantation. It is referred to as Choppee okra, named for the community from which it came, Smith said.

Choppee okra was one of several heirloom vegetables on display, along with pole beans, peas and tomatoes.

Agricultural research like this is particularly important in the Midlands because of its sandy, nutrient-deficient soils, Smith said.

“The South Carolina sand hills have some of the worst soils in the world. We are really right above beach sand,” Smith said. “You can grow on sandy soil but you really have to work with your county agent on your soil samples and put the pencil to your inputs.”

Smith demonstrated tomatoes grown on different mulch treatments and with rolled-and-crimped cover crops. To account for soil nutrient deficiency, he applied six pounds per 100 feet of row with gypsum, a type of calcium sulfate. He applied rock phosphate at a similar rate, as well as three pounds per 100 feet of row with magnesium potassium sulfate. An organic fertilizer containing six percent nitrogen, six percent phosphorus and six percent potassium was also applied.

Smith found that grafting, a process that involves fusing the top of a fruit-producing plant with the more disease-resistant root of another plant, was an unnecessary expense because soil-borne diseases were not an issue at the Sandhill REC.

Tomato spotted wilt virus

Tomato spotted wilt virus
Image Credit: Scott Miller / Clemson University

Tomato spotted wilt virus, which is caused by a virus carried by small insects called thrips, was a major problem, however, he said. The best combatant to spotted wilt is a plant with tested resistance, Smith said.

“The Amelia variety is resistant to spotted wilt,” Smith told attendees of the demonstration. “Celebrity is a good-flavored variety, but you can see down that row that it was decimated by spotted wilt.”

The hot, dry climate in the Midlands, as well as the sandy soil, makes irrigation critical as well, Smith said. Smith used drip irrigation on his plots and recommends irrigating only 30 minutes per cycle on these very sandy soils. Exceeding that will just waste water and leach nutrients below the root zone of these sandy soils. For his tomatoes, Smith irrigated four times daily, 30 minutes for each cycle.

Smith’s demonstration likely will be the first of many going forward at the Sandhill REC, allowing farmers to see first-hand the techniques that boost yields and profit.

“We are working hard to revitalize our agricultural research here at the station, with a particular focus on urban farming, new and beginning farmers, conservation practices and agribusiness,” Sandhill REC Director Kathy Coleman said.

Powell Smith

Powell Smith
Image Credit: Scott Miller / Clemson University

That includes Smith’s vegetable research plots and a new farm incubator project that will open small plots for startup farmers to begin growing their businesses. Participants will receive instruction in business planning and food safety, as well as farming advice from Extension experts and an on-site coordinator. They’ll also have access to greenhouse space, farming equipment and, in the future, a commercial kitchen to package fresh foods for market.

“Clemson for me brings the technology and the business experience. They really help with product marketing,” said Clemons, who is among the participants in the incubator.

Clemons founded Dianne’s Call, a nonprofit that provides nutrition education and works to increase access to healthy foods in underserved communities. At the incubator, Clemons is working with a group of about 20 women to begin growing food to sell affordably in low-income neighborhoods. Dianne’s Call operates a mobile farmers market.

“We are increasing access to healthy foods by bringing the food to people,” Clemons said.