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20 WINES&VINES January 2016 WINE INDUSTRY NEWS N orth Coast, Calif.—Grape- growers in Napa and So- noma counties experienced an explosion of Pierce's disease (PD) in 2015, and it's attributed to the native blue-green sharp- shooter, not the threatening glassy-winged sharpshooter that so far has been excluded from the counties by rigid quarantines. Researchers are hoping to un- cover the reason behind the spike in PD, but many people are specu- lating that the mild weather we've had the past two winters may be a culprit. Rhonda Smith, the viticulture advisor for University of California Cooperative Extension in Sonoma County, said, "A huge increase in Pierce's disease occurred in vine- yards that are traditional hot spots as well as in sites not normally affected, pointing to an epidemic associated with warm winters." She said growers removed tens of thousands of dead vines in the spring and replanted, but demand for plants outstripped supply. Smith added that the incidence of PD has been slowly increasing during the past few years, and a larger increase was seen in 2015. In the North Coast, PD is generally associated with riparian areas or other landscaping that provides alternate hosts for the insect vectors. Doug McIlroy of Rodney Strong Vineyards is on the board of the Sonoma County Winegrape Com- mission. His family has grown grapes in the Russian River for more than 40 years. "I've never seen PD like this before," he exclaimed, noting that outbreaks seem to occur in cycles. "It seems to peak around warmer El Niño years." McIlroy said the grapevine ill- ness seems especially damaging to early leafing varieties such as Chardonnay and Pinot Noir. He finds it especially prevalent in the Russian River Valley southwest of Healdsburg, Calif., and in Dry Creek Valley. It's not as much a factor north of Healdsburg. "It's also probably colder during the winter there," McIlroy noted, adding, "and many of the streams that feed the river don't have much riparian area." Smith's UCCE counterpart in Napa County, Dr. Monica L. Coo- per, also reports more PD. "There has been a marked increase in PD in 2015, with some growers re- porting incidence rates as high as 50% of blocks, especially in re- gions where background PD pres- sure is historically high." Cooper added, "We have expe- rienced a severe impact on vines, since systemic PD infections are generally lethal within a few years." Steve Moulds, the owner of Moulds Family Vineyard in the Oak Knoll District of Napa Valley and current president of the Napa Val- ley Grapegrowers, agreed. "There has been a tremendous resurgence of PD this past year. We have dis- cussed different factors such as drought-induced stress. I do know that the Big Ranch Road area has been particularly hard hit, but even non-riparian areas near our ranch are feeling some effects." Garrett Buckland is vice presi- dent of Premiere Viticultural Ser- vices and vice president of the Napa Valley Grapegrowers. "We deal with PD every year, but we've seen a bigger spike this year. It's two to three times worse," he said. "For us in Napa Valley, the odd patterns of weather are a bigger problem than the drought." —Paul Franson C reedmoor, Texas—Officials destroyed more than 500 bottles of wine found among the private collection of Rudy Kurniawan, who was convicted in 2013 of producing and selling wines under counter- feit labels, making millions of dollars. Officers from the U.S. Marshall's Office destroyed the bottles at a landfill in Creed- moor on Dec. 10, 2015, after ruling their provenance could not be verified and there- fore they were unfit to be resold. According to prosecutors, Kurniawan purchased large amounts of bulk wine, then affixed bottles with labels replicated from prestigious châteaux and exemplary vintage years, often showing particular fondness for Burgundian wine producer Domaine de la Romanée-Conti. He was sentenced to 10 years in prison and is serving his sentence in Taft, Calif. —Kate Lavin 'Huge' Outbreak of Pierce's Disease Kurniawan's Cache Crushed LYNZEY DONAHUE / US MARSHALS LEARN MORE IN PERSON Jan. 13: UC viticulture advisor Dr. Monica L. Cooper has planned an in-depth discussion of the PD problem during a meeting of the Napa Valley Viticultural Technology Group. The talk is open to all concerned parties (registration is required) from 10 a.m. to noon at the Century Theaters in Napa. Feb. 10 and 11: In Sonoma County, UC viticulture advisor Rhonda Smith will address PD on Feb. 10 at the UCCE 2016 Sonoma County Grape Day at the Wells Fargo Center for the Arts in Santa Rosa. She also will hold a meeting about PD the following day, Feb. 11, in the large conference room at the UCCE Sonoma County office.