Four U.S. Vegetable Lab Findings on Melons and Collard Greens

sweettatersIn 1937, a year after the U.S. Vegetable Laboratory opened in Charleston, the News & Courier ran a story about goings-on at the facility, explaining “the exact purpose and duties of the station are not usually quite clear to the average person.” Nearly 80 years later, that observation still holds.

But while perceptions of the Savannah Highway lab — and Clemson University’s neighboring Coastal Research and Education Center, which focuses on regional agriculture — haven’t changed much, the nature of the resident scientists’ work has evolved dramatically.

The lab’s staff scientists continue to puzzle out responses to crop threats posed by pests and diseases, but now they’re doing so with the aid of state-of-the-art equipment, such as gene sequencers. (Although they’re not opposed to low-tech solutions: A team working to fight off fruit rot grows its trial phytophthora in rice saturated with V8 juice.)

“Agriculture is a science-driven industry,” supervisory research geneticist Mark Farnham says, contextualizing the lab’s contributions to a sector that’s worth $34 billion in South Carolina alone.

lunchTo show off the results of their recent work, the U.S. Vegetable Lab and Clemson’s research center yesterday hosted an open house, which was structured like a professional science fair. Very enthusiastic scientists presented their test plants and charts, explaining what they’ve learned and what they hope to accomplish in the year ahead. At the event’s end, everyone retired to a conference room to eat non-infected crops collards, peas, rice and sweet potatoes raised at the lab — and pity the astrophysicists and meteorologists who can’t make a meal of what they study.

In coming months, many of the lab’s projects will be more fully explored in The Post and Courier. But here’s a quick glance at a few of the findings given the open house treatment:

1. Seeing bacteria in a new light

In order to prevent and control harmful bacteria, farmers need to know exactly which strain has infected their crops. The problem is nobody can identify microorganisms just by looking at them. But research plant pathologist Pat Wechter has come up with a way to detect Pseudomonas, a blight which affects collards: When he shines a bioluminescent signal on Pseudomonas diseased leaves, they glow.

“If you go out with a black light and your field glows, I’d say just go home and have dinner,” says Wecheter, who first published his research last year.

Once scientists are able to locate a bacteria, they can begin to scheme control strategies, he adds.

plantsseeds2. Keeping watermelon healthy

When research geneticist Amnon Levi examined the genes of 400 heirloom varieties of watermelons, he discovered most heirlooms have very similar genetic profiles. But the standard gene roster is short on genes associated with disease resistance, which is why he’s started studying wild watermelons from Africa’s Kalahari Desert.

“We find several of these have high resistance,” Levi says.

Unfortunately, the wild watermelons aren’t especially tasty, but Levi is investigating the possibility of swiping their genes to strengthen domestic heirlooms, such as the Charleston Gray.

plants23. Another reason to eat greens

Very few eaters worry about getting enough glucosinolates in their diets, but the compound is associated with antibiotic, anti-cancer and antimicrobial properties. Broccoli has loads of it.

But glucoraphanin, a kind of glucosinolate, had never been reported in collards before Farnham and his team discovered it in heirloom collards collected from around the Southeast. A few kinds of collards grown in the coastal plains of the Carolinas had higher glucoraphanin levels than broccoli.

“That leads me to believe these might be valuable genetic sources,” biological research technician Zach Stansell says.

4. Graft is good

Grafting is an ancient practice, but – more to the point – it’s a costly one. Meticulously attaching a vulnerable fruit start to a healthy rootstock takes time and skill: Clemson University associate professor Richard Hassell calls it an art.

“It’s labor intensive,” he says. “You have to find people; usually ladies, because they’re more dexterous with their fingers. And then you have to pay them.”

Hassell’s team is trying to overcome the expense of grafting with an automated machine, capable of producing 300 grafted plants an hour. He demonstrated the grafting of seedless watermelon and hybrid squash.

Although it’s still not cheap, Hassell hopes to further lower the $1.30-per-transplant fee.

“We get better quality fruit with grafting,” he says. “You’ve all been in the grocery store and seen all the moisture in a watermelon container. With grafted, they don’t contain as much water.”

Additionally, grafted watermelon can remain in the field three weeks after ripening, allowing farmers to pick them when the weather and economic conditions are ideal.

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