Brazilian squash may offer answer to profit-robbing Southern pumpkin diseases

By Marni Katz

Fall is an important time for Darrell and Ellen Dalton’s Pumpkin Hollow, when visitors scour their 25 acres of pumpkins for the perfect jack-o’-lantern.

With its hayrides, pony rides and pumpkin patch, Pumpkin Hollow is a big attraction for a short period of time for residents of Piggott, Ark. But growing those pumpkins in the northeast corner of the state is no simple feat, Ellen Dalton says.

“Growing pumpkins in Arkansas is a huge challenge because of the heat and humidity,” Dalton says. “Pumpkins fare better farther north where they have dryer air and cooler summers than we have.”

A promising import from Brazil

But the Daltons have their eyes on promising research into a Brazilian line of disease-resistant Cucurbita moschata being conducted by University of Georgia associate professor George Boyhan.

The C. moschata lines were collected from Brazil in 1996 by Dr. Gerard Krewer and have become the starting materials for field selection for superior pumpkin-type squash lines at the university.

For the Daltons, eventual commercial varieties from the lines could reduce the need for constant scouting and subsequent costly fungicide sprays.

Producing pumpkins, even 25 acres, in the South is an expensive and time-consuming proposition. The Daltons spend an average of $300 to $400 per acre every year in preventative fungicides, primarily to combat powdery and downy mildew.

Survivor—Southern United States

While Boyhan’s C. moschata squash line is different from the Cucurbita pepo squash varieties typically produced for fall pumpkins, Boyhan has been selecting for a round melon and burnt orange color.

Most important, the C. moschata line has a much higher level of virus and disease resistance and thrives even under adverse conditions of heat and humidity.

“We’ve been selecting over several generations of open pollinated varieties and at this point we have produced very consistent traits within the lines,” says Boyhan, who’s based in Statesboro.

The lines also are showing very low levels of disease, even without fungicides, and yields comparable to commercial varieties. In two years of fall pumpkin field trials comparing the experimental variety against the industry standard C. pepo pumpkins, the experimental lines yielded significantly more.

In 2003, the experimental varieties produced between 13,000 and 30,000 pounds per acre with virus disease ratings between 1 and 2, while commercial varieties produced from 1,400 to 7,300 pounds per acre and had disease ratings of 4 or higher.

The virus disease rating scale runs from 1 to 5, with 1 indicating no visible symptoms and 5 showing severe symptoms. In 2004, the experimental varieties produced about 16,000 pounds per acre, while the commercial varieties yielded no pumpkins at all. No disease ratings were available for the trial.

A few wrinkles to iron out

The Brazilian varieties the university has bred have a distinct character and some production problems that commercially still need to be overcome, Boyhan says.

The fruit sometimes has trouble standing on its bottom, which is not always flat. A yellow ground spot is produced where the fruit comes in contact with soil, likely as a result of lack of sun.

“I think it’s a great looking pumpkin in any case,” Boyhan says. “It’s a different animal than what some people are used to seeing.

It has a brighter burnt orange color than you see in conventional pumpkins.” Dalton, however, says that when it comes to Halloween pumpkins, “different” is certainly not a negative, and people are always looking for something unusual for their jack-o’-lantern.

Despite some drawbacks, Boyhan believes the variety can definitely have a niche for fall pumpkin producers in the South who, until now, have had few options for economically growing a crop.

“There’s nothing you can currently grow in Georgia or in the Deep South without losing your shirt,” he says. “I’m not sure what consumers will think about it, but we’ve had a couple field days and saw good interest, especially among growers who have pick-your-own-type operations where this variety could be seeded out with other pumpkins and the vines are reasonably healthy. We also think in and of itself, the pumpkin has a lot of appeal.”

Coming soon—commercial releases

Boyhan increased the seed this year and has produced about 300 pounds of foundation seed, which he hopes to make commercially available to seed companies as early as this fall. The final trial on the experimental variety was to be harvested in September or October.

Once trial results are approved by the university’s variety release committee, the University of Georgia Research Foundation will enter into licensing agreements with private seed companies to commercialize the variety.

Dalton says that when seed becomes available, Pumpkin Hollow hopes to get enough to at least plant a half-acre plot on her farm to try the new variety. “We are looking for seed to do a trial here,” she says. “Just looking at our initial data, it looks like something that we would at least try to get our hands on some seed and try it on our farm. It’s been bred for the South and that is very intriguing for us.”

Ken Ludwig, with SeedWay Co. in Elizabethtown, Pa., recently heard about the variety during a presentation at the Georgia Vegetable Growers Conference in Savannah and says it shows promise and the company hopes to get some seed into a trial soon.

While he doesn’t expect the new pumpkin to become a major commercial variety, he says it should hold some interest among a niche group of Southern growers who want to produce fall pumpkins and also help move fall pumpkin production farther south.

“It’s not going to be a mainstream pumpkin, per se, but it does expand the regions that pumpkins can be grown beyond your standard pepo Halloween pumpkins,” Ludwig says.