Can Sweet Potatoes Save the World?

Some foods are known as seasonal wonders, making an appearance only once or twice a year when families gather for holiday feasts. Cranberry sauce, pecan pie, eggnog. Sweet potatoes, typically with tiny marshmallows roasted on top, were once on that list. But sweet potatoes are on the rise.

They have become increasingly recognized as a superfood packed with essential vitamins and nutrients, and are now enjoyed throughout the year — in upscale restaurants, as a healthier alternative to French fries, and in products as varied as vodka, sausage and muffins.

Behind that rise is a remarkable success story with its roots at NC State, one that reaches into the familiar farms of eastern North Carolina and to the often forgotten corners of a handful of African nations. It is a story of science and salvation, of a pair of breeders who defied ridiculous odds to develop a new sweet potato variety that rescued the industry in North Carolina.

It is also a story that holds out promise for the future, well beyond the shores of North Carolina and its acres of sweet potatoes.

The work of a professor at NC State could transform the way sweet potatoes are eaten in several African countries, improving the health of young children and their mothers and creating new economic opportunities in Africa’s bustling cities and smallest villages.

Antonio Magnaghi is among those in Africa banking on sweet potatoes. He is well on his way to turning his small bakery on a crowded industrial street in downtown Nairobi, Kenya, into a thriving business that sells sweet potato muffins, fries and other products in the country’s top hotels, markets and coffee shops.

Antonio Magnaghi:

“The possibilities, they are endless with sweet potato.”

Counting on Covington

It was not that long ago, though, that the outlook for sweet potatoes was grim at best. Less than two decades ago, sweet potato farmers across eastern North Carolina were telling their kids to find another type of work because they couldn’t count on a decent crop of sweet potatoes.

They were primarily planting a variety known as Beauregard that was developed in Louisiana, and it was not well suited to North Carolina’s soil and climate.

There were too many unpleasant surprises — like getting your first look at a bad poker hand — when farmers dug up their sweet potatoes each fall. They kept finding odd shapes and sizes that wouldn’t sell in grocery stores.

Without a new variety, fewer and fewer sweet potatoes were going to be grown in North Carolina.

Jerome Vick, the patriarch of a large family farm in Wilson, North Carolina:

“Beauregard sweet potatoes were as ugly as homemade soap.”

“Our livelihood was at stake.”

Yencho, a William Neal Reynolds Distinguished Professor and leader of NC State’s sweet potato and potato breeding and genetics program, was one of the masterminds behind Covington, the variety now grown throughout North Carolina.

He also leads an effort, fueled by a $12 million grant from the Bill and Melinda Gates Foundation, to bring molecular science to sweet potato breeding programs in Uganda and a handful of other sub-Saharan countries in Africa.

His ultimate goal is twofold — to use sweet potatoes to increase economic opportunities and to get sweet potatoes’ nutrients into the bellies of children and pregnant women who suffer from such serious vitamin A deficiencies that they are in danger of going blind.

It is an optimism that focuses less on the big picture in favor of countless small victories. It takes into account the Ugandan breeders he has trained (such as Mwanga and Benard Yada ’14, Ph.D., who runs the government’s sweet potato research efforts) as graduate students at NC State.

It takes into account the scientists he works with on a bucolic research campus in Nairobi, Kenya, to develop a program using advanced molecular breeding techniques that will help sweet potato farmers in Africa, North Carolina and elsewhere.

It takes into account home-grown entrepreneurial efforts he has seen in Africa that embrace the economic and health benefits that come with orange-fleshed sweet potatoes.

Yencho, during his visit to the farm in Arua, where researchers have been working with sweet potatoes for only three years, as he surveys the scene with Yada and a group of Ugandan breeders traveling with him and some of the farm staff:

“I like to think in terms of pebbles, ... and how a pebble tossed into a pond creates ripples.”

“The field looks beautiful..."

“The rows are well laid out. Your weed management is really exceptional.”

“That’s goat damage,” someone tells him. “Say what?” Yencho asks. “Goat damage,” he is told again. Yencho laughs. “I’m an animal lover,” he says, “so that’s OK.”

He detects what he calls “drought damage,” but wonders about other damage to the crops.

It Takes Time

Ken Pecota is crouching in a field of sweet potatoes on a research farm in Clinton, N.C. A flap on his cap protects his neck from the sun as he works his way down dusty rows to check on several varieties being tested.

Pecota, a sweet potato researcher and breeder at NC State, was also one of the breeders behind Covington. It was clearly the signal achievement of his career, but he is determined to develop other varieties that will find their way into farmers’ fields.

Some are for niche markets, such as organics, while others are more suitable for processing into fries, chips or other uses. And there are no guarantees that problems won’t eventually develop with the Covington breed.

Kitavi is working with Yencho and others to correct that. Her labs are housed on a research campus that is fenced off from the chaos and poverty that abounds in Nairobi. Here, she spends her days extracting the DNA from sweet potato varieties, which is then sent to NC State’s Genomic Sciences Laboratory to be sequenced.

It is all part of an effort to develop a set of genetic markers that could be used to bring more predictability to the process.

Such knowledge could be used, for example, to reduce the 60,000 new varieties that NC State’s program starts on the testing regimen each year to as few as 10,000–12,000. That’s less time and money spent on the front end, and a greater likelihood of positive results.

In part, that’s because there is not likely to be just one variety — like Covington in North Carolina — that will be the answer to the varying conditions throughout Africa.

Craig Yencho:

“We need to speed up variety development.”

“You have to breed African varieties in an African context.”

Cultural Differences

In Uganda, virtually everyone is a farmer. Dried sweet potatoes — none of them orange —are readily available from roadside vendors. Yencho’s team stops at one point on the highway from Soroti to Kampala to talk with a group of women selling buckets of dried sweet potato slices for 5,000 Ugandan shillings a bucket — that’s about $1.33.

The women, joined by their children and husbands, lead the visitors into their cluster of a half dozen huts to show off a large rock embedded in the ground — it is where they dry the sweet potatoes grown in a small plot nearby. (It is also, they say while pointing to an indention in the rock, a place where Jesus once stood.)

Mwanga, who led the early push for orange-fleshed sweet potatoes in his country, estimates that roughly 90% of households have their own farm, which may be no more than a half-acre. That’s 2 million households.

Compare that to North Carolina, where fewer than 400 farmers grow sweet potatoes, and most of them are part of a commodity group that works with the university and shares information. Extension agents spread throughout the state make it relatively easy to spread the word of new developments or problems for sweet potatoes.

In Uganda, there are more than 50 different languages spoken. That means there are more than 50 different ways to say sweet potato, from “acok” in Ateso, the language spoken by the people showing off their drying rock, to “maku” in Lugbara. Communication is difficult at best.

Bonny Oloka ’18, Ph.D., finished his graduate work with Yencho last year and returned to Uganda to work as a sweet potato breeder. He never ate orange-fleshed sweet potatoes growing up in Kampala, and says the challenge of replacing other sweet potatoes in his country is great.

Bonny Oloka:

“Every region you go to you will find completely different people.”

“The language is different, the cultures are different, the foods are different.”

Several days later, while in Uganda, Yencho sees another success story in a small village outside of Kampala. After driving down a winding, deeply rutted dirt road, Yencho meets Sekiyanja Joweria, who runs the Bagya Basaya (O.F.S.P) Potato Growers and Processors cooperative.

The office is a small, plain building with large metal doors and a handful of plastic chairs. Around the back is a single, makeshift greenhouse for growing sweet potato vines.

The cooperative, run by 100 women, sells orange-fleshed sweet potato vines to farmers and mills sweet potato flour that can be used to make pancakes, donuts and bread. Joweria does not speak English, so a translator helps as she shares her story.

But the success is apparent at the farms where it is grown. At Scott Farms in Lucama, N.C., the fifth generation now farms 12,000 acres in five counties. In a gleaming industrial space, computers direct the packing of 40,000–50,000 pounds of sweet potatoes an hour — every week of the year — to ship to U.S. and foreign markets.

About 85% of the sweet potatoes are sent to fresh markets, while the remaining 15% is sold to processors — a far cry from the days when some farmers dumped as much as 30% of their crop in the woods because the potatoes were too big or too small or otherwise unfit.

Dewey Scott,co-owner, told a group of researchers and breeders visiting last year from Africa, South America and elsewhere:

“Whatever is in that bin is used for something.”

At Vick Family Farms, warehouses can store more than a half million bushels of sweet potatoes and about half of their sweet potatoes are exported to Europe, something that would have been unimaginable two decades ago.

Jerome Vick:

“All the stars lined up.”

“We have a good variety, good storage conditions, a year-round supply and we could go back after those markets we lost.”

And farmers are finding creative ways to market their sweet potatoes. Yamco, a company in Snow Hill, N.C., distills Covington Gourmet Vodka, which has won top awards competing against vodkas from around the world.

Carolina Innovative Food Ingredients, a company in Nashville, N.C., makes sweet potato juice and dehydrated sweet potatoes that can be used in baked goods, beverages and sauces like ketchup and syrup.

The Sharps, who grow about 500 acres of sweet potatoes and raise hogs, had the help of NC State food scientists to develop a sausage infused with sweet potato juice, sweet potato puree and chunks of sweet potatoes. It is served, among other places, in Fountain Dining Hall at NC State.

Alan Sharp:

“It’s a better potato now.”

“Twenty-five years ago, it wasn’t very good, it was dry and stringy.”

Some even say sweet potatoes are trendy. Kelly McIver, executive director of the N.C. Sweet Potato Commission, notes that sweet potatoes are now found on the menus of high-end restaurants. One of the appetizers served at a wedding reception she attended last year combined sweet potatoes with goat cheese and a pimento.

Kelly McIver:

“It’s a sexy food.”

A sexy super food that can rescue a struggling industry and prevent blindness in remote areas of the world? That’s a lot to ask of a simple sweet potato. Even Yencho, ever the optimist, chuckles at the suggestion that the sweet potato could save the world.

But its reach is likely to grow, if only because consumers are more conscious about the health benefits of what they eat. Farmers in Uganda and other African countries are going to keep growing sweet potatoes, including those that are orange when you cut them open.

And Pecota is not going to stop working on new varieties anytime soon.The possibilities are endless. And that’s without any tiny, roasted marshmallows.