In the foothills of the Ozark Mountains, researchers at the University of Arkansas Fruit Research Station are working to develop a new fresh fruit category similar to table grapes.
The muscadine, a grapevine species, grows natively in the Southern United States. The plant produces fruit similar but not quite the same as table grapes, explained Margaret Worthington, director of the Fruit Breeding Program, located in Clarksville, Arkansas.
“It's actually in a different subgenus than grapes,” Worthington said. “It's got a different chromosome number, kind of like a horse and a donkey.”
The fruit has strong disease resistance, an appealing characteristic for growers, she said. But consumption of the fruit has remained mostly concentrated in the region.
“They have had limited appeal beyond the kind of traditional Southern consumers because they have a real thick skin and a gummy flesh,” Worthington said.
“We, and other breeding programs, have been working on breeding them to have a better texture where it's more similar to a table grape and also seedless.”
Muscadine vines at the University of Arkansas Fruit Research Station - Photo: UA System Division of Agriculture
The fruit has long served to make wine, due to its floral aroma and flavor profile. But Worthington envisions muscadine becoming a fresh fruit category that falls somewhere between grapes and berries at the supermarket.
“We hope that by the time I retire, you'll see muscadine on every supermarket shelf around the country and maybe grown in Brazil also,” Worthington said.
“They have kind of a bad reputation because of the texture, but the new varieties are really, really excellent.”
Muscadine research and breeding have been in progress at the university since 2006. By next year, Worthington hopes those efforts will result in the program’s first muscadine releases.
Since the university's Fruit Breeding Program began in 1964, it has developed and commercialized around 70 genotypes, including strawberries, table grapes, and blueberries. Beyond muscadine research, the university also has active breeding for blackberries, peaches and nectarines.
The breeding station in Clarksville sits in a rainy, humid region with hot summers and cold winters.
"We have rocky, kind of silty clay-loam soil where we're breeding. We tend to have kind of acid soils, not extremely acid but somewhat acid," she said.
The fruit developed here is adapted to the U.S. South but bred for adaptability in a global marketplace, Worthington added.
“Arkansas fruit breeding products are grown on every continent except for Antarctica,” she said. “We definitely are interested in our varieties being grown in these places and using our genetics as much as we can in different parts of the world.”
The university’s biggest breeding program currently is for blackberries. The South is one of two major production regions for U.S. blackberries, alongside California.
“We get a lot of rainfall. So, we have a lot of disease pressure, and we get easily 1,000 chill hours a year,” she said. “That being said, we have developed a lot of blackberry varieties that are used in many places throughout the world, including some lower chill environments.”
University of Arkansas varieties, like Ouachita, Ponca and Navaho, have become leading varieties for fresh market production in the United States.
The Sweet-Ark®-Immaculate is the latest blackberry release from the University of Arkansas. - Photo: UA System Division of Agriculture
In February, the university released a new, thornless variety, Sweet-Ark® Immaculate.
“Our primary reason for deciding to pull the trigger on this is that we've had a lot of people interested in expanded options for late season floricane-fruiting varieties in the U.S.,” Worthington said. “Those late season varieties can command a cost premium relative to early season varieties because there's less product available from Mexico that time of year.”
Mexico supplied 97.8% of fresh blackberries imported to the United States in 2023, according to the USDA, with 232.5 million lbs. Guatemala supplied 2.1% of imports.
The Sweet-Ark® Immaculate should help Southern growers extend their seasons and potentially their volume.
“People want new varieties that are high yielding and have good shipping ability,” she said. “The fruit firmness is really quite, quite good and the yield potential is very good as well … It has a smaller stature plant than our standard older varieties, but that doesn't seem to be affecting the yield potential.”
The firmness and post harvest qualities of the fruit were essential breeding elements for a late-season blackberry, Worthington explained, due to the increase in pest pressure from spotted wing drosophila in the summer months.
At the Clarksville Fruit Research Station, the fruit has typically been ready for picking between the last week of June through mid-to-late July.
