[pensive music] - [Narrator] It's harvest time again for sweet potatoes.

These southern staples are a cultural icon of North Carolina.

The beloved vegetable unites people around the table and support a huge farm industry.

- Right here behind me, we are in the middle of peak harvest.

It's a beautiful October day.

We've got all of our guys out here, making sure we get a beautiful crop into our storage this year, and we are ready for the 2023, 2024 season, and ready to pack these potatoes and send them on to their final destinations.

- [Narrator] These workers from Mexico came to North Carolina on a temporary agricultural employment visa.

They may stay as long as six months as they fulfill jobs in the farming industry, which is facing a shortage of labor.

[pensive music] Taylor Hill is a third-generation farmer at J. Roland Wood Farms in Johnston County.

Granddaughter of James Roland Wood, the company's founder, Hill grew up helping her family on the farm.

After graduating from North Carolina State University, she's been marketing and selling the family's crops.

- So, 100 wood farms.

To bring a new perspective to the table, especially in our farm, I'm the youngest one here, and it's really nice to be able to bring a female perspective, but also bring a younger audience in perspective.

- [Narrator] Since its start in 1967, J. Roland Wood Farms now cultivates more than 1,500 acres, producing up to 30 million pounds of sweet potatoes a year.

Statewide, the UNC Carolina Demography program reports that in 2020, sweet potatoes added $375 million to North Carolina's economy.

That ranks as the state's third most valuable crop.

The top-selling sweet potato variety was the Covington.

[machine whirring] [sweet potato clattering] Crop scientist, Craig Yencho, spearheaded North Carolina State University's efforts to develop the variety.

- Covington was the result of a long-term breeding program before in the performance.

Until released Covington in 2005, the major competitor for Covington was a variety called Beauregard.

The thing that Covington did better than Beauregard was that Covington performed year in and year out, yielded well in a wide range of situations, circumstances, and packed out much better.

And that's really what helped Covington to succeed.

[engine humming] [equipment whirring] - [Narrator] The Covington variety now accounts for 90% of sweet potatoes grown in the state, but crop scientists are looking to improve it.

To help in that effort, farmers can volunteer to plant new varieties that Yencho and his team think have potential.

Scientists track the crop success in the field.

The partnership with farmers is a critical piece to the breeding program's success.

[people chattering] Another important piece includes guidance from the Horticultural Crops Research Station in Clinton, where Hunter Barrier connects farmers with crop scientists.

- We fail so that farmers don't have to, so we try to solve production challenges and give growers answers.

[engine humming] [air brake hisses] - [Narrator] Shortly after switching to the Covington, J. Roland Wood Farms opened a new packing facility in 2017.

After harvest, workers sort sweet potatoes into two different grades, and then pack them into wooden crates before they go into storage.

There, sweet potatoes undergo a process known as curing that turns starches into sugars, giving them their distinctive sweetness.

Although the Covington variety has brought Hill and her family success, she anticipates challenges ahead.

- Covington, it's had a good run.

It's doing good, but it's slowly starting to become a thing of the past.

[camera shutter clicking] - One of the big challenges right now in sweet potato production is a new pest in North Carolina called the guava root-knot nematode.

And it has potentially devastating consequences to our international markets.

- [Narrator] The guava root-knot nematode is an invasive worm that comes from the tropics.

The pest feeds on sweet potatoes' roots and deprives the crop of needed nutrients, herding crop yields.

Yencho says a top priority for his team is to produce a new variety with quality similar to the Covington, but with the resistance to the nematode.

While scientists are testing potential new varieties, they encourage farmers to look for signs of nematode damage in the field, and report it to the North Carolina Department of Agriculture.

[machine whirring] [vehicle alarm beeping] - It's still very strong, don't get me wrong.

In North Carolina, it's the biggest variety we grow, but they're definitely doing a lot of research to give us a new variety, and I'm excited to see what is gonna come in the next few years.

- [Narrator] In the meantime, workers are busy getting the current sweet potato crop ready for market.

This truck is leaving the Benson packing facility in Johnston County for its 12-hour trip to a New York City wholesale market.

The sweet potatoes could be in grocery stores the next day.

- I grew up around agriculture, of course, I grew up here on the farm.

But as I got older, I realized how much I loved being here.

It was good for me to be here with my family.

Working with my family has been something I've always enjoyed all my life.

And I plan to continue here, and I hope one day I can bring along a fourth generation.

[light switch clicks] [lever handle clicks] [door thuds] [pensive music]