Truffle travails lead to triumph for CAES researcher, industry partners

The trouble with truffles – the pricey, edible soil fungus synonymous with nose-to-the-ground dogs and flavorful dinners in five-star restaurants – is that they’re hard to grow. Soil and water conditions must be managed. The weather must be moderate. The tree host must be in good health. If it’s too hot, too wet, too dry, too cool, or any of an assortment of more nebulous conditions that even experts can’t always pinpoint, they won’t grow.

With so much effort – and money – required to get into the truffle business, the whole proposition may seem like a waste of time; indeed, most attempts at establishing truffle orchards in the U.S. have failed, despite millions of dollars of investment. But the payoff for a successful truffle harvest can make it all worthwhile. According to the U.S. Department of Agriculture’s 2021 National Retail Report for specialty crops, truffles can sell for hundreds of dollars a pound; the most celebrated varieties can sell for more than $1,000 per pound.

Mycologist Omon Isikhuemhen, Ph.D., holds a Bianchetto truffle harvested in North Carolina. He wants to make the state the nation’s largest truffle-producer.

Omon Isikhuemhen, Ph.D., a mycologist In the Department of Natural Resources and Environmental Design in the College of Agriculture and Environmental Design, has devoted much of his career to the study of mushrooms and truffles. A respected specialist in shitake cultivation who has helped North Carolina farmers get into mushroom cultivation, Isikhuemhen now wants to do the same for truffles, helping the state’s farmers take advantage of the demand for this high-value commodity.

He and his team have succeeded where others have failed thanks to their willingness to experiment with the type of truffle, the kind of tree and a secret inoculation mixture Isikhuemhen said came to him in a dream. With this mix, he was able to generate an estimated 200 pounds of truffles in 2019 for a grower in Warren County, catching the industry’s attention worldwide.

Now, he and his team are working to build on that success.

“It’s our goal that North Carolina will become the largest truffle-producing state in the nation,” Isikhuemhen said. “Right now, we have new grant to try to expand the host range for the white truffle Tuber borchii. We are also trying to research and improve on various aspects of the technology to improve on yield from fields in different parts of the Southeast using various host trees. We want to learn which microclimates and soil dynamics are the most conducive.”

Truffles are found underground near tree roots, similar to an underground mushroom. But unlike that biological cousin, it’s not always apparent when, or if, they’re present. Dogs, or in some countries, pigs, can sniff them out from the aroma they produce; described as “earthy, pungent, musky” thanks to pheromones and other compounds they make, it’s the aroma that sells the truffle, even moreso than the taste.

And they need time. Often grown from trees whose roots have been intentionally inoculated with truffle spores, truffles can take five to nine years to start producing. According to experts, it can cost $25,000 an acre to set up a truffle orchard; even then, there’s no guarantee of a successful harvest. Truffles only grow on certain species of tree; to grow significant numbers of them, farmers must grow both the tree and the fungus, and encourage them to work together symbiotically.

Nancy Rosborough, CEO of Mycorrhiza Biotech, follows one of her truffle-sniffing dogs through a plot of pines. Rosborough’s company, Mycorrhiza Biotech, is experiencing truffle-growing success after partnering with Isikhuemhen.

Truffle culturing was popular in centuries past, but revived worldwide in the 1970s when France and Italy hit jackpot by finding the right conditions to grow black winter truffles and white truffles, two varieties for which those countries have become famous. Prospective growers in the U.S. tried to follow suit in the late 1990s, but despite millions of dollars in investment, most of those attempts failed for reasons that were unclear, according to experts.

Isikhuemhen became interested in truffles during this time, and watched as North Carolina put together a team of researchers to develop an industry for the black winter truffles called the Perigord, after the region of France where they are commonly grown.

Unimpressed by the high-value, but notoriously finicky and slow-growing Perigord truffles, he instead decided to try growing a variety of white truffle called the Bianchetto on the roots of loblolly pines, the standard timber tree in the Southeast, using his own growth media to inoculate the roots of the pine seedlings with truffle spores before they are planted. A medium-sized player in the truffle world, the Bianchetto had been overlooked, according to Isikhuemhen, in the industry’s rush to the pricer European varieties. But the Bianchetto known as Tuber borchii, which sells for around $500 per pound, seems to tolerate conditions in the American Southeast and grow well on pine trees, two factors that drew Isikhuemhen’s attention.

Isikhuemhen and his industry partner Nancy Rosborough, chief executive officer of Burlington company Mycorrhiza Biotech, announced a breakthrough truffle harvest in 2017 using his method of inoculation, and Mycorrhiza became the first grower in North America to produce Bianchetto truffles on loblolly pines.

“We did the research, then moved to the field, and now, we have truffles,” Isikhuemhen said at the time.

Other growers and the culinary market were slow to warm up to the idea, however; the team was forced to wait to celebrate until two years later, when Isikhuemhen, Rosborough and their client Thomas Edward Powell III experienced spectacular success with Powell’s truffle orchard at Burwell Farms in Warren County. Powell is the owner of LabCorp, the world’s largest clinical diagnostics company; after joining forces with Rosborough and Isikhuemhen in 2010, he was rewarded with a 30-pound Bianchetto truffle harvest in 2019.

Expecting a few hundred truffles from his two-acre plot, Powell and his chief scientific officer, Richard Franks, reaped a few thousand instead using the microbial system devised by Isikhuemhen which, he said, grows truffles five times faster than any other.

That success was highlighted by author Rowan Jacobsen, whose article “Has the American truffle finally broken through?” appeared in Smithsonian magazine this year.

For an agricultural state like North Carolina, where growers are still recovering economically from the demise of the tobacco market, truffles can be a niche crop – particularly for small and limited-resource farmers, Rosborough said.

“You can make enough to save the family farm,’ said Rosborough, whose company Mycorrhiza Biotech is named for the botanical term for the symbiotic relationship between the truffle – the fruiting body of the fungus – and the host plant. Rosborough knows family farms well; a native of Washington, D.C., she moved in 2005 to the farm her mother had grown up on in Gibsonville, and immediately noticed that the area’s small farms were losing ground to suburbs.

Motivated by her desire to save the area’s family farms, including her own, Rosborough found Isikhuemhen while searching for potential crops to grow, and the two have partnered ever since.

Now, with their truffle triumph secure, they are helping Burwell Farms expand its truffle orchard; Mycorrhiza Biotech has more customers; and Rosborough has planted some truffles on her own farm.

“We were never doing this just to make money,” Rosborough told Smithsonian magazine. “The goal has always been to get this technology into the hands of small farmers. If, in a few years, there are 50 farmers in each of the Southeastern states growing truffles on small plots and using that money to hold onto their land, then we can say it worked.”