Did you know? Sweet potatoes are the top- ranked “superfood” in a list of healthiest foods published by The Center for Science in the Public Interest. Mangoes BY BILL KRUEGER are No. 2. PHOTOGRAPHY BY MARC HALL, NC STATE Can Sweet Potatoes Save the World?

NC State rescued the sweet potato industry in North Carolina and helped it grow into a global powerhouse. Now the university is leading an effort to breed sweet potatoes that could Did you know? A large sweet potato, baked provide economic opportunities and with its skin intact, can contain more than 1,700 better nutrition for people in several micrograms of vitamin A — about twice the recommend- African countries . ed daily amount.

30 31 NC State Alumni Magazine NC State Alumni Magazine North Carolina. Year after year, from one field to another, it could be counted on to produce a high percentage of what are known as “number ones,” with the familiar shape, size and look to be sold in grocery stores and farmers’ markets. By 2017, the amount of sweet potatoes grown in North Carolina had nearly doubled and the state had reclaimed its place as the leading Some foods are known as seasonal wonders, making an appear- producer of sweet potatoes in the United ance only once or twice a year when families gather for holiday States. Jim Jones, who grows about 1,500 acres of sweet potatoes in Nash County, says feasts. Cranberry sauce, pecan pie, egg nog. Sweet potatoes, Covington was “the best thing that’s happened in the sweet potato business.” typically with tiny marshmallows roasted on top, were once on The combined efforts of NC State research- ers, professors and extension agents, working that list. But sweet potatoes are on the rise. They have become closely with farmers and an engaged trade group, have transformed sweet potatoes into increasingly recognized as a superfood packed with essential a year-round economic powerhouse that is vitamins and nutrients, and are now enjoyed throughout the now shipped from North Carolina to Europe and other corners of the globe. Some farmers year—in upscale restaurants, as a healthier alternative to French have described it as a perfect example of the work that a land-grant university such as NC fries, and in products as varied as vodka, sausage and muffins. State should do. “We just couldn’t operate without NC State,” says Pender Sharp ’71, a by a $12 million grant from the Bill and Melinda The Covington sweet potato was fifth-generation farmer in Sims, N.C., about Gates Foundation, to bring molecular science named for Henry M. Covington, Behind that rise is a remarkable success story an hour’s drive east of Raleigh. to sweet potato breeding programs in Uganda an extension specialist at NC COUNTING ON COVINGTON Did you know? with its roots at NC State, one that reaches It was not that long ago, though, that the out- But that’s only part of NC State’s sweet and a handful of other sub-Saharan countries State from 1946–74. He was Despite the name, sweet into the familiar farms of eastern North look for sweet potatoes was grim at best. Less potato story. in Africa. His ultimate goal is twofold — to use known as “Mr. Sweet Potato” for potatoes are not potatoes. Carolina and to the often forgotten corners than two decades ago, sweet potato farmers sweet potatoes to increase economic opportu- his work promoting the crop and The edible portion of pota- of a handful of African nations. It is a story across eastern North Carolina were telling nities and to get sweet potatoes’ nutrients into his leadership in the formation of HALF A WORLD AWAY the U.S. Sweet Potato Council. toes are tubers, while that of of science and salvation, of a pair of breeders their kids to find another type of work because Craig Yencho is crouching in a field of sweet the bellies of children and pregnant women a sweet potato is a storage root. Sweet potatoes are who defied ridiculous odds to develop a new they couldn’t count on a decent crop of sweet potatoes in the remote northwest corner of who suffer from such serious vitamin A defi- more closely related to sweet potato variety that rescued the indus- potatoes. They were primarily planting a vari- Uganda, not far from a massive tent camp that ciencies that they are in danger of going blind. morning glories (bottom). try in North Carolina. It is also a story that ety known as Beauregard that was developed is home to thousands of refugees from South Sweet potatoes are already a staple of the holds out promise for the future, well beyond in Louisiana, and it was not well suited to Sudan. He has driven more than seven hours diet for many families in Uganda, who eat Base countries for Craig Yencho’s And a sweet potato is not the shores of North Carolina and its acres of North Carolina’s soil and climate. There were from Kampala, the country’s chaotic capital them steamed in banana leaves or simply sweet potato work. the same thing as a yam. sweet potatoes. The work of a professor too many unpleasant surprises — like getting city, across the Nile River and past a pack of boiled, sometimes with every meal. But most Sweet potatoes are native to Central and South America, at NC State could transform the way sweet your first look at a bad poker hand — when wild baboons and a couple of wandering ele- of the sweet potatoes grown in Africa would Countries where the project has while yams are a tuber native potatoes are eaten in several African countries, farmers dug up their sweet potatoes each phants to get to a research farm in the town of be unfamiliar to American consumers. In- trained sweet potato breeders. to Africa and Asia. Yams have improving the health of young children and fall. They kept finding odd shapes and sizes Arua. He is struggling with a stick to dig into stead of orange, they have white, cream-col- rougher, scaly skin. their mothers and creating new economic that wouldn’t sell in grocery stores. Or, as one the dirt, which has been baked rock hard by ored or yellow flesh, and are not as sweet or

opportunities in Africa’s bustling cities and farmer puts it, Beauregard sweet potatoes the unforgiving equatorial sun and the delayed soft as their American cousins. They also smallest villages. were “as ugly as homemade soap.” Without a onset of the rainy season. What he finally pulls don’t have all the nutrients found in orange- Antonio Magnaghi is among those in Africa new variety, fewer and fewer sweet potatoes out of the ground is a scrawny excuse for a fleshed sweet potatoes. banking on sweet potatoes. He is well on his were going to be grown in North Carolina. “Our sweet potato. It is also riddled with holes that But changing consumer preferences may Sway to turning his small bakery on a crowded livelihood was at stake,” says Jerome Vick, the are signs of weevils, a small but pervasive pest be the easy part of Yencho’s challenge — early industrial street in downtown Nairobi, Kenya, patriarch of a large family farm in Wilson, N.C. that can wipe out a crop. promotional efforts touting the health benefits into a thriving business that sells sweet potato Then, in 2005, breeders at NC State hit the Yencho, a William Neal Reynolds Distin- of orange foods such as sweet potatoes and muffins, fries and other products in the coun- jackpot. They came out with a sweet potato guished Professor and leader of NC State’s mangoes have created some converts. “Kids try’s top hotels, markets and coffee shops. variety they called Covington, which had begun sweet potato and potato breeding and genetics are attracted by the orange color,” says Robert “The possibilities,” Magnaghi says with as a botanical seed in 1997 and progressed program, was one of the masterminds behind Mwanga ’01 phd, a Ugandan scientist who won an irrepressible grin, “they are endless with through years of field trials. Within a few Covington, the variety now grown throughout the World Food Prize in 2016 for his pioneering sweet potato.” years, Covington was nearly all anyone grew in North Carolina. He also leads an effort, fueled work to promote orange-fleshed sweet potatoes

32 WINTER 2018 ALUMNI.NCSU.EDU 33 NC State Alumni Magazine NC State Alumni Magazine in his country. “Also, the softer the food is, the dating back to his wanderlust days as a young better it is for kids. It’s easier for them to eat.” Peace Corps volunteer in St. Kitts and Nevis. The bigger challenge is breeding new vari- It is an optimism that focuses less on the big eties of orange-fleshed sweet potatoes that can picture in favor of countless small victories. be grown in Uganda. Weevils take advantage It takes into account the Ugandan breeders of dry, cracked soil brought on by drought (and he has trained (such as Mwanga and Benard a lack of irrigation) to burrow their way into Yada ’14 phd, who runs the government’s sweet growing sweet potatoes, and wipe out more potato research efforts) as graduate students than 70 percent of the crop in most years. at NC State. It takes into account the scientists “Everywhere that sweet potato is grown [in he works with on a bucolic research campus Uganda], you will find weevils,” says Mwanga. in Nairobi, Kenya, to develop a program using And orange-fleshed sweet potatoes, which advanced molecular breeding techniques that typically have less starch and are therefore less will help sweet potato farmers in Africa, North dense than most of the sweet potatoes grown Carolina and elsewhere. It takes into account OPPOSITE: Craig Yencho in Uganda, are softer and easier for weevils to home-grown entrepreneurial efforts he has and Benard Yada ’14 phd burrow into. “We still have a long way to go,” seen in Africa that embrace the economic and survey sweet potato vines Mwanga says, “to get something that farmers health benefits that come with orange-fleshed at a research farm outside can leave out in the field and not worry about sweet potatoes. Kampala, Uganda; Yencho the weevil.” “I like to think in terms of pebbles,” Yencho and Mercy Kitavi work with As insurmountable as the challenges may says, “and how a pebble tossed into a pond sweet potato samples in a lab in Nairobi, Kenya. seem, Yencho is undaunted. He laughs when creates ripples.” ABOVE: Kitavi extracts DNA he is asked during a visit to Uganda and Kenya He sees some of those ripples during his from a sweet potato. last year if it feels like he is forever pushing a visit to the farm in Arua, where researchers heavy rock up a steep hill, like a modern-day, have been working with sweet potatoes for gray-haired Sisyphus. “Yeah, it can feel like only three years. “The field looks beautiful,” that sometimes,” he says. But Yencho prefers a he says as he surveys the scene with Yada and different outlook, one that reflects an optimism a group of Ugandan breeders traveling with

AmericansPiling used on to theeat a lot Sweet of sweet potatoes Potatoes — per capita consumption peaked at 29.5 pounds in 1920. By the 1990s, though, it had fallen as low as 3.7 pounds before starting to rebound since the turn of the century.

That’s still a far cry from sweet potato consumption in Uganda and Kenya source: international potato center lbs/year7.2 (2016) 137.7lbs/year (2000)

lbs/year (2016) lbs/year (2000) 111.2 4.2 And it still pales in comparison to UGANDA KENYA Americans are eating more white potatoes (think French fries) sweet potatoes — nearly twice consumed by Americans each year. as many as they ate at the turn But the trend for white potatoes is on of the century. the decline. source: u.s. department of agriculture lbs/year220 (2016) lbs/year55 (2016) source: u.s. department of agriculture ALUMNI.NCSU.EDU 35 NC State Alumni Magazine Malinga Emmanuel, a farmer in central Uganda, left, shows off a white-fleshed sweet potato grown and consumed throughout Uganda and other African countries. In eastern North Carolina, Jim Jones, right, holds a Covington orange- fleshed sweet potato, familiar to consumers throughout the United States. No matter where you plant them, growing sweet pota- toes is hard work — as the hands on both these men show.

ALUMNI.NCSU.EDU 37 NC State Alumni Magazine him and some of the farm staff. “The rows are potatoes and come up with a new, distinctive well laid out. Your weed management is really variety — as long as you don’t care too much exceptional.” He detects what he calls “drought about how it turns out. Sweet potatoes have damage,” but wonders about other damage to a much more complex genetic makeup than the crops. “That’s goat damage,” someone tells most vegetables, fruits and grains. Sweet pota- him. “Say what?” Yencho asks. “Goat damage,” toes are a hexaploid, which means they have he is told again. Yencho laughs. “I’m an animal six sets of chromosomes. lover,” he says, “so that’s OK.” So it’s difficult to get the desired mix of traits. NC State’s breeders track 45 different traits — resistance to disease, drought tolerance, IT TAKES TIME Ken Pecota is crouching in a field of sweet shape, color and size, to name just a few — in potatoes on a research farm in Clinton, N.C. A the sweet potato varieties they work with. It flap on his cap protects his neck from the sun takes years of trial and error to test new vari- as he works his way down dusty rows to check eties, and the overwhelming majority end up Want Fries on several varieties being tested. Pecota, a having some sort of fatal flaw that makes them with That? sweet potato researcher and breeder at NC ill-suited for farming or processing. Yencho Ken Pecota spends a lot of his State, was also one of the breeders behind and his team start every year with 60,000 time these days thinking about Covington. It was clearly the signal achieve- new varieties, knowing that most of them McDonald’s. Pecota, a sweet ment of his career, but he is determined to will fall short at some point during seven (or potato breeder at NC State, is develop other varieties that will find their more) years of field tests. At times, the process trying to develop a new variety way into farmers’ fields. Some are for niche can seem downright cruel — a couple of years that will enable the fast food markets, such as organics, while others are after releasing Covington, Yencho and Pecota chain and others like it to start selling sweet potato fries. more suitable for processing into fries, chips released another variety named Hatteras that CLOCKWISE FROM TOP LEFT: But aren’t sweet potato or other uses. And there are no guarantees had performed well in all the field tests. But Ken Pecota shows off some of the sweet fries already found on the that problems won’t eventually develop with after farmers started planting it, Hatteras potato varieties being tested at a research menus in many restaurants? the Covington breed. developed something called internal necrosis, farm in Clinton, N.C.; Pecota uses his phone They are, but not in fast-food “If you’re ever satisfied as a breeder, you which creates brown flecks in the flesh. Within to record data on several varieties; farmers check on a bin of sweet potatoes restaurants, where operators need to retire,” he says. “There’s always some- two years, no one was growing Hatteras. Pecota want a fry that will stay crispy grown on the research farm. (without the use of a batter) for thing you can make better.” was once curious about just how difficult his job the 10 or 15 minutes it takes to The varieties he’s testing today have was, and calculated that there is as much as a get home after picking up food already shown some promise, but there are one-in-two million chance of breeding a sweet at the drive-thru window. far more tests to be done before any conclu- potato that satisfies the criteria they try to meet. That may sound simple, sions can be reached. They sit on top of the “If you look at that number, “ Pecota says, but Pecota (shown above in dirt, having been dug up earlier, and Pecota “you’ll say, ‘That’s it, I quit.’” a food lab in Schaub Hall) insists that’s not the case. is conducting the most basic tests before the Pecota is joking. As a kid in suburban New Put simply, if you increase the potatoes are sent to the lab for further analysis. Jersey, he loved working on puzzles of all level of starch that helps a fry “See, this guy rotted,” he says as he grabs a sorts — jigsaw, word, number — and he brings stay crisp, you risk losing some sweet potato. “That’s not a good sign.” But he that same passion to his work as a breeder. of the sweet potato’s health also notes some positive signs: “They’ve got “That’s exactly what breeding is,” he says. “It’s benefits and run the risk of the good uniformity, right? They’re all kind of the a big puzzle.” potato turning brown when it’s same shape. There’s a nice lightness, a really Efforts are further complicated by the fried. So Pecota says breeders are focusing on changing the nice finish to it. The skin texture is beautiful.” sweet potato’s status as what is considered an nature of the starch, rather He slices into some of the sweet potatoes “orphan crop.” Unlike crops like corn, wheat than the amount of starch in and takes a bite, and estimates the amount of and rice, there have been no big corporations a potato. “It’s really compli- starch (an important consideration for vari- involved with sweet potatoes, which has cated,” he says, “but it’ll make eties bred primarily for processing into fries historically been considered a subsistence the difference between a limp or chips). “I know that one’s got a medium crop for poor people. That means no cor- French fry and a crispy French fry with no batter.” starch,” he says at one point. porate dollars for research and technology, The practiced ease with which Pecota and it is why sweet potatoes lag behind other approaches his work masks the fact that it is crops when it comes to the latest, molecular- incredibly difficult to breed sweet potatoes, based breeding programs. “Sweet potatoes be it in North Carolina or in Africa. It’s easy are under-researched,” says Mercy Kitavi, a

enough to cross two different varieties of sweet molecular breeder who works in Kenya with BILL KRUEGER BY PHOTOGRAPHS

38 WINTER 2018 NC State Alumni Magazine produce about Orange is the New Green the program Yencho is leading. “When you Sweet potatoes mean cash for North Carolina farmers, and the crop has of the sweet potatoes had a tremendous economic impact — on sales and jobs — in the state. NC counties 1 look at the complex genetics of sweet potatoes, (Sampson, Johnston,4 Wilson and Nash) grown /2in the state everybody is like, ‘Not me.’ We don’t know the North Carolina farmers produced answer to seemingly simple questions like the 1.7 billion pounds of sweet potatoes genetics of beta carotene.” in 2017, nearly triple the 595 million Kitavi is working with Yencho and others to grown in the state in 2005 (the year Covington was introduced). 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 North Carolina is the leader in domestic sweet North Carolina also accounts State’s program starts on the testing regimen 1.7 potato production, growing roughly for more than each year to as few as 10,000–12,000. That’s billion lbs. 60 percent 70 percent less time and money spent on the front end, in 2017 of the sweet potatoes eaten in the United States. of the sweet potatoes that are and a greater likelihood of positive results. exported around the world. “We need to speed up variety development,” bucket — that’s about $1.33. The women, Along a highway in central Uganda, Yencho says. joined by their children and husbands, lead vendors sell slices of dried white- 595 In part, that’s because there is not likely to be the visitors into their cluster of a half dozen fleshed sweet potatoes. million lbs. just one variety — like Covington in North Caro- huts to show off a large rock embedded in the in 2005 lina — that will be the answer to the varying con- ground — it is where they dry the sweet pota- ditions throughout Africa. “Covington wouldn’t toes grown in a small plot nearby. (It is also, work in Africa,” Yencho says. “You have to breed they say while pointing to an indention in the Those sales led to an African varieties in an African context.” rock, a place where Jesus once stood.) That led to almost estimated additional Mwanga, who led the early push for orange- fleshed sweet potatoes in his country, esti- CULTURAL DIFFERENCES In Uganda, virtually everyone is a farmer. mates that roughly 90 percent of households Dried sweet potatoes — none of them orange — have their own farm, which may be no more are readily available from roadside vendors. than a half-acre. That’s 2 million households. million million $ $ About 5,000 workers Yencho’s team stops at one point on the high- Compare that to North Carolina, where in sales in 2016. in economic impact in the state are associated with sweet way from Soroti to Kampala to talk with a fewer than 400 farmers grow sweet potatoes, 350 according170 to Michael Walden, a potato production in North group of women selling buckets of dried sweet and most of them are part of a commodity William Neal Reynolds Distinguished Carolina, both on farms and potato slices for 5,000 Ugandan shillings a group that works with the university and Professor and extension economist in the supply chain.

LIFE CYCLE OF A SWEET POTATO

STARTING TRANSPLANTING HARVESTING CURING Sweet potatoes are not started from Sprouts are cut and The harvesting of sweet Most sweet potatoes are seed. Instead, they are grown from transplanted — either potatoes typically starts in cured for 4–7 days at vine cuttings that are called sprouts or from a greenhouse or August. Tractors are used 80-85 degrees so that slips. Some farmers start their sprouts “bedding” field — to to flip them on top of the they can then be stored in greenhouses, but others grow sprouts another field in May ground and then, because for up to a year at by “bedding” small sweet potatoes in and June. the thin skin can be easily 55 degrees with 85-90 March. Whole sweet potatoes are put scarred, they are harvested percent humidity and on top of the ground and then covered GROWING by hand. They are graded adequate ventilation. with a thin layer of soil and plastic. It takes 90–120 frost-free days to and sorted according to grow a sweet potato. They grow their size. under the ground.

40 WINTER 2018 ALUMNI.NCSU.EDU 41 NC State Alumni Magazine NC State Alumni Magazine Two continents, two greenhouses: Jim Jones, left, checks on one of several green- houses he maintains at his farm in Bailey, N.C. Jones grows sweet potato vines for his own farm and to sell to other farm- ers. Sekiyanja Jowe- ria, right, checks on the vines in the single greenhouse run by a sweet potato growers cooperative outside of Kampala, Uganda. The cooperative, run by Joweria, sells vines to nearby farmers.

ALUMNI.NCSU.EDU 43 NC State Alumni Magazine shares information. Extension agents spread health benefits of orange-fleshed sweet pota- More Sweet throughout the state make it relatively easy to toes throughout Africa, says Rwanda, Malawi Potatoes Please spread the word of new developments or prob- and Mozambique have all seen an increase The N.C. Sweet Potato Com- lems for sweet potatoes. In Uganda, there are in the consumption of orange-fleshed sweet mission has recipes for burritos, burgers and pound cakes. We more than 50 different languages spoken. That potatoes. “Those are all very important coun- asked several people in the means there are more than 50 different ways tries that have significant vitamin A deficiency sweet potato business how to say sweet potato, from “acok” in Ateso, problems,” Low said during a visit to the they liked to eat theirs. the language spoken by the people showing research campus in Nairobi. off their drying rock, to “maku” in Lugbara. One such success story can be found in Jerome Vick, a farmer in Communication is difficult at best. downtown Nairobi, on the second floor of a Wilson, N.C. “Just baked, with nothing on it. No cinnamon, phd Bonny Oloka ’18 finished his graduate non-descript building on a crowded street. no butter. If it’s cooked right, it work with Yencho last year and returned to Inside, Magnaghi is at work in his bakery, don’t need nothing.” Uganda to work as a sweet potato breeder. He where he makes sweet potato muffins for some never ate orange-fleshed sweet potatoes grow- of the top hotels in the country, and is trying to Jim Jones, a farmer in Nash And They Look ing up in Kampala, and says the challenge of develop sweet potato fries for Kenya’s largest County, N.C. He likes leftover Pretty, Too replacing other sweet potatoes in his country chain of coffee shops. sweet potatoes for breakfast. “Fry it with some bacon or Sweet potatoes have a place is great. “Every region you go to you will find Magnaghi describes himself as a “food at the table, but sweet potato sausage. Slice it about as thick completely different people,” he says. “The application specialist,” but he is an entrepre- vines have a place in the as your finger and lay it in that garden. We’re talking about language is different, the cultures are different, neur at heart. He has worked in Italy, Australia grease and just brown it a little sweet potato ornamentals, and the foods are different.” and Rwanda, but was excited to return home bit. It’s probably not healthy, chances are you’ve seen them But Oloko, who was trained as a biochemist, to Kenya to explore the possibilities of sweet but it’s really good.” before. The colorful plants — in chose to go into breeding because he believes potatoes. He says that Kenyan consumers phd shades of purple, green, yellow in the power of food to improve the health of share his excitement, but that he struggles Robert Mwanga ’01 , sweet and red — can be found in potato researcher in Uganda. his fellow Ugandans. “I think it’s attainable,” to get enough orange-fleshed sweet potatoes large planters outside D.H. Hill “The steamed one is fine, but Library at NC State and as part he says, “because 15 years ago there was almost for his many projects. “People are buying it when I came to [the U.S.], Antonio Magnaghi shows of the landscaping in cities and no orange-fleshed sweet potato in Uganda. I because of the health reasons,” he says. “And I found the French fries.” off a batch of sweet pota- homes all over the country. didn’t have it. My parents could not get it. But then also because it’s a nice orange. It’s bright to muffins at his bakery in For the past several years, Ken Pecota, sweet potato now we know where to get it.” and it attracts a lot of people.” Yencho tells downtown Nairobi, Kenya. NC State has worked with a breeder at NC State. “I love Likewise, Sadik Kassim, director of research him that in North Carolina sweet potatoes are Robert Mwanga ’01 phd company in California to sell some of the desserts the Jap- at the government farm in Arua, says there being used in beer and that sweet potato syrup on a research farm out- sweet potato ornamentals that anese make. They actually use is plenty of interest in orange-fleshed sweet is being used as a substitute for honey. “Oh, side Kampala, Uganda. Ken Pecota breeds on a research the purple ones or the white farm in Clinton, N.C. The test potatoes in his region along the Nile River. He that I would like to visit,” Magnaghi says. [sweet potatoes], and they’re plot is an artistic wonder of estimates that 15 percent of the households in Several days later, while in Uganda, Yencho usually dry and not particularly different colors, leaf shapes the region — compared to 5 percent in the rest sees another success story in a small village sweet. But they have a really and textures. of the country — grow and eat orange-fleshed outside of Kampala. After driving down a nice creamy flavor.” For Pecota, it’s a welcome sweet potatoes. “West Nile is where sweet winding, deeply rutted dirt road, Yencho meets break from his normal breeding Pender Sharp ’71, a farmer in potato can make a difference,” he implores Sekiyanja Joweria, who runs the Bagya Basaya work. Breeding sweet potatoes Sims, N.C. “I really like it with a for consumption can be tedious Yencho during a meeting before heading out (O.F.S.P) Potato Growers and Processors coop- little cinnamon sugar on it, lying work — seven to nine years into the fields. “Our market is there. Our prob- erative. The office is a small, plain building beside a ribeye steak.” of field tests, gathering and lem is if we can produce a supply of good and with large metal doors and a handful of plastic analyzing all sorts of data, an clean vines [for growing sweet potatoes].” chairs. Around the back is a single, makeshift Craig Yencho, director of incredibly low rate of success. the sweet potato breeding Yencho appreciates the sentiment, but greenhouse for growing sweet potato vines. program at NC State. “Just a But with ornamentals, Pecota points out some of the region’s challenges, The cooperative, run by 100 women, sells can cross two varieties and baked sweet potato. That’s see whether he got something including a lack of irrigation and storage orange-fleshed sweet potato vines to farmers it. With maybe a little bit of interesting within a year. “It just capacity for harvested sweet potatoes. “This and mills sweet potato flour that can be used butter. No brown sugar. My kids opened up the other side of my district has been ignored,” he says. to make pancakes, donuts and bread. Joweria drive me crazy when they put brain,” he says. does not speak English, so a translator helps as that on.” He likes them sliced and grilled, too. “A little bit of she shares her story. SWEET SUCCESS olive oil, a little bit of salt and While they are not as obvious as the success The cooperative started more than 30 years pepper, maybe throw some that farms in eastern North Carolina have ago and, initially, grew only white-fleshed sweet rosemary on top.” had with sweet potatoes, encouraging signs potatoes. But after an international health can be found throughout Africa. Jan Low, an organization found that several children in ON THE WEB: ncsweetpota- agricultural economist who has promoted the the village were malnourished, they were toes.com/sweet-potato-recipes

44 WINTER 2018 ALUMNI.NCSU.EDU 45 NC State Alumni Magazine NC State Alumni Magazine All Year Long Sweet potatoes might still be a seasonal crop if Mike Boyette ’76, ’86 ms, ’90 phd, had not traveled to northern California back in the late 1980s. Boyette, a Philip Morris Professor of Biological and Agricultural Engineering, visited the University of California at Davis, outside of Sacramento, to study how produce farmers Did you know? handled their crops after harvest. It was there that he discovered Because the skin of sweet the secret that would transform North Carolina’s sweet potatoes potatoes is so easily nicked, into a crop that could be sold throughout the year. most of the harvesting of At the time, as much as a third of the sweet potatoes grown in the crop is still done by hand. North Carolina were discarded. “There was really no good way to White potatoes are cheaper store sweet potatoes,” Boyette recalls. The problem was that when than sweet potatoes, in part, sweet potatoes were put in crates in a warehouse, farmers had no because the process of way to keep all of them cool. Large, industrial fans would keep the growing white potatoes is sweet potatoes cool in the top crates, but the air wasn’t getting to more mechanized. most of the sweet potatoes. “When a potato is sitting at 85 or 90 degrees, it’s thinking it’s time to start growing, and so they start putting on sprouts,” Boyette says. “If it puts on sprouts, it’s using up the dry matter in the potato and the potato becomes like a cork. There’s nothing there. They’ve got the form of a sweet potato, but there’s nothing there.” So Boyette took what he saw at some California farms and devised a way to pull the cooling air through all of the crates in the warehouse. Sensors placed inside the crates monitor the temperature of the sweet potatoes. He called his technique “negative horizontal ventilation.” After returning from California, Boyette approached a farmer in eastern North Carolina about trying his new technique. It meant the farmer had to spend some money, but he quickly got a return on his investment. “He made a killing,” Boyette says. “He was probably the only farmer in the United States who had sweet potatoes at that time.” It didn’t take long for the word to spread, and Boyette soon found himself traveling to farms throughout eastern North Carolina to help them build warehouses incorporating the technique. Today, such storage facilities are common on sweet potato farms, with the larger operations able to store more than half a million bushels. Boyette visited a large farming operation in Wilson, N.C., last year, and watched sweet potatoes being packed for shipment a year after they had been harvested. “They were beautiful,” he says.

HOW NEGATIVE HORIZONTAL VENTILATION WORKS Large fans are mounted along the top of one wall. Those fans create negative pressure to pull air horizontally through stacked bins of sweet potatoes. By pulling the air through all the bins, all of the sweet potatoes can be maintained at the same temperature.

HEATER MOUNTED REFRIGERATION FANS

AIR FLOW

OPEN AREA

Linwood Vick ’96 checks on stacks of sweet pota- toes at his family’s farm 46 in Wilson, N.C. WINTER 2018 ALUMNI.NCSU.EDU 47 NC State Alumni Magazine NC State Alumni Magazine convinced to switch to orange-fleshed sweet breeders visiting last year from Africa, South potatoes in 1998. “We found a lasting solution,” America and elsewhere. Beer, Biscuits she says. “We started seeing improvement.” At Vick Family Farms, warehouses can Joweria leads Yencho to a nearby field of store more than a half million bushels of sweet and Baby Food sweet potatoes, where they compare notes on potatoes and about half of their sweet potatoes Van-Den Truong had eaten sweet potatoes as a child in growing and harvesting techniques. As is true are exported to Europe, something that would Vietnam and studied them as at farms throughout Uganda, most of the work have been unimaginable two decades ago. “All a graduate student and then is done with little more than hands and hoes. the stars lined up,” says Jerome Vick. “We have professor of food science in The cooperative has been a financial success, a good variety, good storage conditions, a year- the Philippines. But he was enabling the village to pay the school fees for round supply and we could go back after those amazed when, as a post doc 15 children to go off to college. Joweria’s son markets we lost.” at NC State in the mid-1990s, he visited a sweet potato farm graduated with a degree in agriculture and her And farmers are finding creative ways to in eastern North Carolina. He daughter is studying journalism. market their sweet potatoes. Yamco, a company was impressed by the scale of While poverty is evident throughout Africa, in Snow Hill, N.C., distills Covington Gourmet the operation and the farm’s Yencho says a closer look reveals opportunities Vodka, which has won top awards competing ability to store sweet potatoes such as those found in a small urban bakery or against vodkas from around the world. Caro- for months. a rural Ugandan village. “There is real signif- lina Innovative Food Ingredients, a company in But he also saw an oppor- tunity. “The main focus was icant poverty here,” he says. “But if you start Nashville, N.C., makes sweet potato juice and the fresh market,” he says. to peel that away there is an entrepreneurial dehydrated sweet potatoes that can be used in “There was not much process- spirit. There is an emerging middle class and baked goods, beverages and sauces like ketchup ing there.” a vibrancy that is really beginning to emerge.” and syrup. The Sharps, who grow about 500 At the time, there were two acres of sweet potatoes and raise hogs, had the primary methods for process- Computers direct sweet potatoes through help of NC State food scientists to develop a ing. Chunks of sweet potatoes a series of assembly lines in a large NOTHING WASTED could be canned, but they had packing house, above, at Scott Farms in For all of Covington’s success, there was sausage infused with sweet potato juice, sweet to be sterilized and heated Lucama, N.C. The facility can pack as never one moment when Yencho and Pecota potato puree and chunks of sweet potatoes. It is to more than 200 degrees, much as 50,000 pounds of sweet pota- felt it was appropriate to pop the champagne served, among other places, in Fountain Dining which destroyed many of the toes an hour to be shipped to U.S. and corks. They have a patent on Covington, Hall at NC State. nutrients and often turned foreign markets. Below, Alan and Pender which is described in the legal documents as “It’s a better potato now,” Alan Sharp says. them brown. The other method Sharp sort though a bin of sweet potatoes an “invention,” and NC State licenses it to be “Twenty-five years ago, it wasn’t very good, it was to freeze large plastic at their farm in Sims, N.C. buckets of sweet potato puree, was dry and stringy.” grown in North Carolina and other parts of meaning bakeries or restau- the country (and even a few other nations). Some even say sweet potatoes are trendy. rants would have to thaw a The licensing generates revenue that is used Kelly McIver, executive director of the N.C. five-gallon bucket of ice. to cover the cost of the university’s breeding Sweet Potato Commission, notes that sweet But in 2006, Truong and program. But in some ways Covington’s suc- potatoes are now found on the menus of high- other NC State food scientists cess just sort of happened, over time, until end restaurants. One of the appetizers served figured out that they could sterilize sweet potato puree it simply became accepted that it was North at a wedding reception she attended last year by using microwaves to heat it Carolina’s sweet potato. combined sweet potatoes with goat cheese and for just 2-3 minutes, and then But the success is apparent at the farms a pimento. “It’s a sexy food,” she says. use an aseptic chamber to where it is grown. At Scott Farms in Lucama, A sexy super food that can rescue a strug- fill a pre-sterilized container. N.C., the fifth generation now farms 12,000 gling industry and prevent blindness in remote The containers could be large acres in five counties. In a gleaming indus- areas of the world? That’s a lot to ask of a simple enough to hold a gallon, six trial space, computers direct the packing of sweet potato. Even Yencho, ever the optimist, gallons or as much as 300 gallons, making it versatile for 40,000–50,000 pounds of sweet potatoes an chuckles at the suggestion that the sweet potato a number of uses. hour — every week of the year — to ship to U.S. could save the world. But its reach is likely Yamco, a company in and foreign markets. About 85 percent of the to grow, if only because consumers are more Snow Hill, N.C., that uses the sweet potatoes are sent to fresh markets, while conscious about the health benefits of what process, says the puree is used the remaining 15 percent is sold to proces- they eat. Farmers in Uganda and other African in beer, liquor, pies, muffins, sors — a far cry from the days when some farm- countries are going to keep growing sweet pota- donuts, energy bars, soups, baby food, ice cream, pet food ers dumped as much as 30 percent of their crop toes, including those that are orange when you and countless other products. in the woods because the potatoes were too big cut them open. And Pecota is not going to stop or too small or otherwise unfit. “Whatever is working on new varieties anytime soon. in that bin is used for something,” co-owner The possibilities are endless. And that’s

TOP PHOTOGRAPH COURTESY OF SCOTT FARMS OF SCOTT COURTESY PHOTOGRAPH TOP Dewey Scott told a group of researchers and without any tiny, roasted marshmallows.

48 WINTER 2018 ALUMNI.NCSU.EDU 49 NC State Alumni Magazine NC State Alumni Magazine