Sweet potato grower works to meet buyers’ demands

Michael Wood, a sweet potato grower in Benson, North Carolina, says his buyers like a product that is consistent in size and quality.
Photos by Rocky Womack.

After a 20-year relationship with his buyers, Michael Wood, grower, packer and shipper at J. Roland Wood Farms in Benson, North Carolina, says the majority of his wholesale and retail clients want to see sweet potatoes with consistent sizing and consistent quality.

One way he meets that demand is by remaining small, yet large enough to respond to a buyer’s needs. For example, if a buyer calls early in the morning, Wood says he can send a truck full of sweet potatoes and have them arrive the following morning, whether it’s to the southern tip of Florida or to New York.

“I don’t have that many customers that I can’t handle what I’ve got,” he says.

Wood currently grows about 900 to 1,000 acres of sweet potatoes. He notes that a great deal of them go to the sweet potato fry market. “The french fry market in the last two years has been real good; now it’s about leveled off,” he says.

Wood says the sweet potato fry has been a real asset to the industry; however, in his opinion, some restaurateurs may have taken advantage of its popularity. “I’m thinking the price is too high on the retail end,” Wood says. “If you go to a restaurant chain and you order sweet potato fries, there’s an up-charge to it.”

The problem comes when diners see that sweet potato fries carry a $2 or greater up-charge; Wood says they will likely choose the less expensive white potato fries. “That’s my theory,” he says. “I may be wrong.”

A study conducted by the North Carolina SweetPotato Commission revealed that about 15 percent of <0x00E0> la carte sweet potato sides are upgrade options, which carry an average of $1.50 more in price per order.

The demand exists, but is slow to catch on. “A study we did in 2013 showed that sweet potatoes in restaurants are in the early stages of proliferation,” says Sue Johnson-Langdon, executive director of the commission. “The sweet potato fry is relatively new to food service, and there are bumps in the road, not a steady rise.”

A large part of that bump in the road is the lack of availability. That was the primary reason why diners didn’t order sweet potatoes, according to the study.

In addition, the study revealed that since 2006, the largest growth in restaurants was with the national food chains, and a good portion of that was due to sweet potato fries.

Besides sweet potato fries, Wood believes that baking is the biggest use for sweet potatoes when they’re purchased by his customers at grocery chains, mom-and-pop stores, or retail and wholesale outlets. In fact, one longtime customer is a bakery that purchases them for use in its pastries and pies.

Large bins of sweet potatoes in the storage facilities/coolers at J. Roland Wood Farms in Benson, North Carolina.

Wood’s observations follow the results of the commission’s study. It showed that diners preferred their sweet potatoes baked whole; fries ranked second, with mashed following.

Sweet potato facts

North Carolina farmers grow more than 60,000 acres of sweet potatoes, almost 50 percent of the country’s total production, according to the North Carolina Department of Agriculture & Consumer Services (NCDA&CS).

As far as tonnage, the leading sweet potato market goes to processors, Johnson-Langdon says. They process canned goods, snack food, baby food, frozen food and various other forms of products. She adds that the fresh market ranks second in pounds sold. That includes retail, food service and the international market.

From October 13, 2013, to February 1, 2014, the NCDA&CS reports that 4,632,328 40-pound cartons of fresh market sweet potatoes were shipped. Of that number, 561,149 cartons went to the food service industry, 3,222,356 cartons went to the retail industry, and 848,823 cartons went to the international market.

The NCDA&CS also indicates that 63,935,131 pounds of sweet potatoes were sent to various processors during the same time period. The department breaks that down as follows:

  • 5,140,416 pounds went to the canning market
  • 8,079,145 pounds went to the chip market
  • 5,654,160 pounds went to the baby food market
  • 28,169,730 pounds went to the frozen food market
  • 16,891,680 pounds went to other markets

Variety selection

Wood plants 90 percent of his variety selection in Covington sweet potatoes and 10 percent in Hernandez. Most of his customers prefer Covingtons for their uniform shape, even if they are not the same size. According to the North Carolina SweetPotato Commission, Covingtons have rose-colored skin and supersweet orange flesh.

North Carolina State University (NCSU) plant breeders Craig Yencho and Kenneth Pecota developed the Covington variety, which was named for extension specialist Henry Covington, according to NCSU. The variety was released in 2005. Covingtons account for 90 percent of the sweet potatoes planted in North Carolina and about 20 percent across the U.S.

Wood usually begins planting his sweet potatoes in mid-May, but last year, due to wet weather, he and other farmers set as late as the end of July. Planting is generally done through the end of June or early July. The ones planted in late July 2013 were mainly used for smaller seed or stock sweet potatoes.

Sweet potatoes planted in June are king, mainly because of better weather conditions. “One of my mother’s uncles always said that June potatoes were better,” Wood says. “I don’t have any data or research to back it up, but what you set in June will be better than what you set in May.”

Wood typically starts digging during the first week of September, right after Labor Day, although some farmers dig in August.

As a rule, he says growers in his area should have finished digging their sweet potatoes by November 1. In 2013, a lot were dug after November 1, giving them time to grow larger. He says as shippers, most are sending out their November-dug sweet potatoes first.

Pest challenges

Wood deals with various challenges at the farm and must stay on top of new options to fight disease, weed and insect pests.

“Last year for sweet potato the most common diseases diagnosed at the clinic were, in order from most frequent to least frequent, fusarium root rot, Geotrichum sour rot, rhizopus soft rot, black rot and scurf,” says Lina Quesada-Ocampo, an assistant professor of vegetable pathology at NCSU. “We did not really get any samples with viral diseases last year at the clinic. We did get a few cases with root-knot nematode.”

Quesada-Ocampo says the majority of fungal diseases are noticed in the field, even though they actually develop postharvest. She suggests that a good crop rotation keeps “pathogen levels down in the fields, as well as starting with pathogen-free material.”

She advises growers to clean facilities as well as possible, avoid wounding the roots, and maintain appropriate environmental conditions such as temperature and humidity. These, if in extremes, can stress the roots and encourage disease.

Other diseases occurring in North Carolina sweet potato fields include sweet potato feathery mottle virus, white rust and pox, notes Chris Gunter, NCSU associate professor and vegetable production specialist.

For storage rot diseases, such as rhizopus, “Use Botran when packing sweet potatoes out,” says Jonathan Schultheis, NCSU professor and extension leader in the Department of Horticultural Science.

The leading weed issue in North Carolina sweet potatoes is Palmer amaranth, Gunter says.

In North Carolina, Michael Wood grows sweet potatoes for the retail and wholesale markets. His sweet potatoes are sold throughout the eastern U.S., from Florida to New York.

Katie Jennings, NCSU research assistant professor in the Department of Horticultural Science, agrees. For Palmer amaranth, she recommends using Valor at 3 ounces per acre at preplant, followed by Dual Magnum at 0.75 pint per acre between seven and 10 days after transplanting. “Of course, the growers cultivate two to three times a season,” Jennings says, “and usually they send in a crew to hand-remove [it]. The Palmer amaranth escapes approximately two times during the season. These weeds should be removed from the field in order to prevent regrowth from the stems [re-rooting].”

Other weeds include annual grasses, pigweed, common cocklebur, common lamb’s-quarter, common ragweed, Pennsylvania smartweed, and yellow and purple nutsedge, according to NCSU.

Gunter says insects appearing in North Carolina sweet potato fields are lepidopteran pests, such as the sweet potato hornworm; southern, yellow-striped and beet armyworms; and spider mites. However, Yencho believes they’re minimal recurring problems. He says the “so-called WDS complex” of insect pests – wireworm, Diabrotica spp. (cucumber beetles and corn rootworms) and Systena spp. (flea beetles) – is more of a concern because they feed on the storage roots of sweet potatoes.

Schultheis recommends using the insecticide Lorsban at preplant for wireworm and flea beetle control. He also suggests using bifenthrin as a soil barrier insecticide.

Others insects that are a concern for sweet potato growers include white grubs, white-fringed beetles, tortoise beetles, leafhoppers, leaf miners, corn earworms and loopers, according to NCSU.

Labor challenges

Wood has to keep his laborers working efficiently and keep track of their work and time. This year he will utilize migrant H-2A labor and expects about 70 workers to come in from another country; however, at harvesttime he may have to bring in a hybrid crew to help out. Sweet potato production is intensive due to the hand labor required, and Wood also needs forklift and truck drivers.

He has to determine what fields need harvesting first, and weather factors heavily in his decisions.

Wood must also monitor temperature in the storage units, which he keeps at 55 to 60 degrees Fahrenheit, with relative humidity at 80 to 85 percent. He says temperatures must be checked every day and adjusted when necessary.

In addition to growing sweet potatoes, Wood plants 210 acres of flue-cured tobacco. He has to plant and fertilize both crops on time, control weeds and diseases, complete harvest in a timely fashion, and then market the crops properly. The time frames for the tobacco harvest and digging of sweet potatoes often coincide.

Despite any challenges, Wood believes that he meets his buyers’ needs and follows the necessary production practices to grow sweet potatoes of a consistent size and quality.

Rocky Womack has written about agriculture and business for more than 25 years and currently serves as a contributing writer and correspondent for agriculture and business magazines, domestically and internationally. In the past, he has worked as a magazine editor and daily newspaper writer. Womack has won numerous awards for his interviewing, writing and in-depth reporting.