Southern Jewel, the latest grape variety issued by the University of Florida’s Institute of Food and Agricultural Sciences, is high-yielding, disease resistant and produces fruit in big bunches.

IFAS developmental biology professor Dennis Gray, who led the team that created the new muscadine variety, says the new grape has been in the works since 1994.

It is Gray’s second grape cultivar release. The first was “Delicious,” also issued this year.

Southern Jewel is the 19th grape cultivar created by UF researchers. In this month’s issue of the journal HortScience, Gray describes Southern Jewel as having “an excellent taste and a crunchy texture with a palatable skin, making it well-suited for fresh fruit consumption.”

Southern Jewel, created with traditional plant-breeding techniques, was grown and compared with other muscadine varieties at the Mid-Florida Research and Education Center in Apopka, starting in 2002. Its ability to produce fruit in bunches made it stand out, Gray said.

“Muscadines typically make very small clusters, maybe just four or five berries,” he said. “This one can make more than 12, sometimes 16 berries on a cluster.”

That allows growers to harvest the grapes by cutting the stem of the cluster rather than picking individual berries, he said. Researchers don’t yet know how much of an advantage that might be, he added.

Southern Jewel is an open release by UF, which means any grower should eventually be able to grow the plant once nursery owners have enough established plants to sell. A few plants may already be available through some nurseries, he said. Interested growers should check the Florida Grape Growers Association Web site at www.fgga.org for information or check with larger nurseries for more information.

During the trials, Gray said researchers used minimal disease control treatments — just one spray per year with copper sulfate — to determine their disease resistance.

Muscadines are typically resistant to Pierce’s disease, which plagues many grape varieties grown in Florida, but they can be susceptible to bitter rot or ripe rot, which cause the berries to decompose. Southern Jewel was resistant to all three diseases.

“You can have the most beautiful plant in the world, but if it won’t survive outside, it’s worthless,” he said.

Jacob Paulk, who owns Paulk Vineyards in south Georgia and has been growing grapes since the 1970s when he planted the crop to replace tobacco, said the prospect of clusters that can be cut at the stem is an intriguing one. Most of his muscadines now must be hand harvested, put onto a conveyor belt and sent into a packing shed, where workers grade and sort them by hand before packing them in small containers. Eliminating that step could mean less expensive grapes for consumers, he said.

A variety that could go from the stem to stores “would be a novel thing for us."