New variety opens new doors

Orange Bulldog allows southern Georgia and Alabama growers to tap into the fall pumpkin market.
Photos by April Sorrow, University of Georgia.

With the popularity of jack-o’-lanterns, fall festivals and holiday pies, pumpkins are a good fall crop. The largest production areas are Illinois, which produces close to 5 million pounds, California, Ohio, Pennsylvania and Michigan. The mid-Atlantic region follows in production, but moving into the deep South, the crop has been more difficult to grow. A variety introduced by the University of Georgia (www.uga.edu) in 2004 may be changing that.

Pluses for the crop

Although the squash’s popularity means that retailers snap much of the national crop up, that actually creates a need for more acreage. Religious and civic organizations that use pumpkin sales as fundraisers are thwarted if they have to pay retail prices. That market is ripe for those wishing to begin or expand pumpkin production.

In addition, the crop is tolerant of most soil types and many climates. Although they demand a long growing season (90 to 120 days) and won’t stand up to frost, pumpkins can be a good second crop for strawberry farmers.

Problems with pumpkins

On the negative side, the orange vegetables don’t thrive in highly sandy soils and can’t tolerate overly wet conditions. Pests are a common woe. Squash bugs, cucumber beetles and, especially, squash vine borers are the worst offenders. The borer, a plump, 1-inch, white caterpillar, is the larva of a .75-inch moth with a red abdomen. In late spring or early summer, the moth lays eggs near a vine’s base. Within a week, the larvae emerge, boring holes to enter the pumpkin stem. These holes and caterpillar excrement are clues to its presence, which causes the vine to suddenly wilt and die.

For growers in such areas as Georgia and Alabama, viruses have made pumpkin production nearly impossible, often taking out the plants before flowering. Several viruses, powdery mildew and downy mildew are responsible for shutting growers out of this fall crop. Because these aphid transmitted viruses can move from plant to plant so quickly, just a handful of the pests can wipe out an entire crop.

Dr. George Boyhan of the University of Georgia inspects an immature Orange Bulldog pumpkin.

Developing Orange Bulldog

UGA scientists George Boyhan, Gerard Krewer and Darbie Granberry set out to make pumpkins a viable crop in the deep South. In 1996, Krewer spotted pumpkins in a South American market and went on to collect C. maxima seeds in remote Brazilian regions, which were interplanted the following year. Supposed hybrids were planted in 1998, forming the basis of the variety that is now known as Orange Bulldog. While the original material included both flat and elongated fruit, the team was most interested in breeding a traditional round pumpkin. By propagating the desirable traits and disregarding unsuitable specimens, this shape was developed. Selections of the best specimens continued until the winter of 2002-03, when the chosen plants were grown in the greenhouse and self-pollinated. Field selection continued until fall 2005 when seed from outstanding fruit were bulked as breeder seed. That spring, foundation seed production had been conducted, producing about 350 pounds.

The Vidalia Farm and the Attapulgus Research Center hosted five variety trials from 2003 to 2005. The first year out, three of the four new lines were pitted against the commercial varieties, Merlin, Gold Strike and Magic Lantern during the fall and showed markedly higher yields with few virus problems. The next spring, typically a time of fewer disease pressures, yields of both standard varieties and the new germplasm were similar. But, in the third fall trial, Gold Strike and Autumn King succumbed to papaya ringspot virus while the new variety thrived. Lab tests showed that the new plant was positive for zucchini yellow mosaic virus, but only exhibited mild leaf discoloration.

A spring 2005 trial confirmed disease resistance. A fall study demonstrated significantly higher yields, and less foliar and virus disease for the UGA pumpkin.

Unveiling the Orange Bulldog

The new pumpkin was presented to growers at a 2004 field day. Farmers, county extension agents and seed companies expressed interest in Orange Bulldog, which is estimated to yield 200 to 300 percent higher yields (13,000 to 20,000 pounds per acre) than other varieties, and is recommended for the entire Southeast.

As is typical with open-pollinated varieties, Orange Bulldog exhibits great variation in shape and size. It produces a pronounced ground spot that isn’t seen in conventional pumpkins. Scientists hypothesize this is light related. When immature, Orange Bulldog is bright yellow and can be prepared like summer squash. By harvest, it develops a cavity like conventional pumpkins and may be carved into a jack-o’-lantern and/or used for pies and other foods. The variety averages about 10 pounds, with color ranging from salmon to burnt orange.

Seed is available for sale from the Georgia Seed Development Commission (www.gsdc.com, 706-542-5640).

Producing pumpkins in south Georgia

Even with the improved variety, it takes more to produce quality pumpkins. UGA gears its guidelines towards south Georgia and similar climates. Boyhan says the following standard protocol works well for Orange Bulldog.

“Having a good fungicide spray program and scouting for insects will result in an even better yield,” he adds. “We have noticed white flies on occasion, which should be treated with two sprays within a five to seven-day time span of an appropriate insecticide.”

A well-drained soil of average fertility is required. Pumpkins don’t thrive in wet or poorly aerated ground, so coarse to medium-textured soils are recommended. A pH between 6.0 and 6.5 is best. Typically, 80 to 90 pounds of nitrogen per acre are adequate.

As pumpkin roots may extend 48 inches into the soil, turn soil to the depth of 8 to 10 inches. Smooth the plot with a rototiller or tooth harrow (disc harrows aren’t recommended). Base potassium and phosphorus feedings upon soil test results.

As the crop requires sunny conditions and a long growing season, plant when the soil reaches 70 to degrees and air temperature is between 65 and 75. Bush-type varieties can be planted with three to five plants in an 8-foot row. Allow 5 to 8 feet between rows. Place two to three semi-bush/vining plants in the same length row, with 8 feet between rows. Vining varieties can only accommodate two plants per row and need 8 to 12 feet between rows. Orange Bulldog is of the vining type. Each acre requires 2 to 4 pounds of seed. Plant at a depth of 1 inch, one to two seeds per hill and thin each pumpkin reach 4 to 6 inches in height.

Since pumpkins are monecious (producing separate female and male flowers on each plant), a pollinator is needed. One beehive per acre is advised, as native bee populations are generally inadequate. Delay insecticide applications until afternoon to spare the pollinating bees.

Some growers are producing pumpkins with a plasticulture system, which can help boost profits. Plastic mulch and drip irrigation give plants a head start in the spring, increase yield and quality, help control weeds and improves irrigation efficiency and moisture uniformity. Fertilizers are more effectively delivered through a drip system. In general, crops grown on plastic may be harvested one to two weeks earlier and may yield 50 to 100 percent more produce. A good way to try the method with pumpkins is to grow them on plastic previously used for an early spring crop, such as strawberries.

Pumpkins may be planted in a single row per bed on white-on-black plastic or black plastic painted white. Varieties producing small to medium vines should be 24 inches apart; large vine types need 30 to 48 inches. More information is available from UGA, other universities and the cooperative extension Service.

Whether you go with plasticulture or traditional planting, Orange Bulldog may be just the ticket to help you cash into the fall pumpkin market.

“This pumpkin is different from traditional pumpkins,” Boyhan says. “It has higher disease resistance. We see it fitting particularly with growers that are pick-your-own and roadside marketers. With pick-your-own growers where fields are ‘reseeded’ each night with new pumpkins, Orange Bulldog is ideal because the vines hold up so well.”

Based in Greensboro, N.C., the author writes articles about horticulture, landscaping, agriculture and travel. She has been a contributor to Moose River Media publications for three years.