Many Projects Under Way To Reduce Pierce’s Disease in Grapes
By Patrick Cavanaugh, Farm News Director
The glassy-winged sharpshooter vectors Pierce’s Disease, which has been devastating grape growers in California for the last few years. California Ag Today recently spoke with Ken Freeze, the Outreach and Education Director for the Pierce’s Disease/Glassy-Winged Sharpshooter Board, a program that uses winegrower’s assessments to fund research. He spoke with us about research that’s been carried out to hopefully find a cure for Pierce’s Disease.
Pierce’s Disease is caused by a bacterium, Xylella fastidiosa, that reduces the vascular function of the vine. The sharpshooter insect vectors the bacteria.
“Andy Walker, with the Department of Viticulture and Enology, UC Davis, has been working on Pierce’s Disease-resistant grapevines. We just released some of those vines to the Foundation Plant Services at UC Davis,” Freeze said. “There are 14 more that are in the wings about ready to go. Some nurseries will be able to get that pretty soon, but already there are about 4,000 of his vines planted. Some of them have been planted in Georgia and Texas, which are real hotspot for the glassy-winged sharpshooter and Pierce’s Disease.”
“Here in California, 2,000 vines were planted in Napa Valley right along the Napa River. Those vines are doing great,” Freeze said.
“We’ve got another project. University of Florida plant pathologist Dr. Don Hopkins has found a benign stain of Pierce’s Disease. It’s like inoculating a vine with a smallpox vaccination. That’s actually a company that’s working on commercializing that now,” Freeze explained.
“We’ve got another project that involves a modified root stalk that sends either a protein or a molecule up into the vine – a non-modified scion – five different ways that stops the Xylella fastidiosa bacteria literally in its tracks before it can cause Pierce’s Disease in the vine. That’s just a small sample of some of the really good projects.”
“One grower told me: ‘It’s not the end of the tunnel, but we can see it,’” Freeze said.