UC Davis Researchers Develop Disease-Resistant Grapes For Winemakers

DAVIS (CBS13) — Groundbreaking research at UC Davis may have finally found a solution to a disease that costs California winemakers millions of dollars every year.

For 20 years UC Davis Professor Andrew Walker has been trying to find a cure for Pierce's disease, which kills grapevines. The disease is transmitted by an insect called the glassy-winged sharpshooter, which is responsible for spreading the bacteria throughout the California wine country.

"About four to five thousand acres are under attack and the vines die in a slow rate between two and five years. There's no escaping that death," Walker said.

Now UCD researchers have created an innovative way to stop the spread by using a grape native to Mexico which is naturally resistant to the disease.

"If they are highly resistant, it won't support the bacteria, and it will slow down and stop," Walker said.

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Scientists use a combination of genetics and crossbreeding to blend traditional wine grapes with disease-resistant plants.

"That allows us to have good quality in the wine grapes and at the same time have stronger disease resistance," Walker said.

The result is five new types of wine grapes. Walker said they made grapes for Cabernet, Zinfandel, Petite Sirah, Chardonnay, and Sauvignon Blanc.

To test the new disease-resistant grapes against the tried and true varieties, researchers held a blind taste test.

"They ranked as highly as traditional wine varieties. They were indistinguishable in many regards, in fact, some of our wines were better than those wines," Walker said.

He's hoping the new varieties will be in bottles soon and said the growers are excited to use the new grapes.

Researchers are now working with nurseries to grow the disease-resistant grapes. They hope to get them distributed across California and other Western states in the next two years.