Issue link: http://winesandvines.uberflip.com/i/131907
GRAPEGROWING mid-1980s were tasked with determining why some vineyards in the North Coast area were suffering outbreaks of phylloxera even though they had been planted with AxR1 rootstock. AxR1 previously had resisted phylloxera damage in California, though it was known to be potentially susceptible. Wolpert, Walker and other scientists from UC Davis determined the outbreaks were due to a new type of phylloxera called Biotype B. Ultimately, Wolpert had to make the difficult announcement that Davis could no longer recommend that growers plant AxR1 rootstock. That change triggered the last major replanting of California's vineyards. Two decades later, growers are again replanting those acres, and often with rootstocks studied by Wolpert. Anderson said he and Wolpert compiled 10 years of data on the performance of rootstocks and how rootstock selections could affect production and ripening of different scion varieties. By drawing on that information, Anderson said growers in California can make much more informed choices when picking the best rootstock for their scion variety and site. "That's a huge legacy, that's a huge pile of data," he said. One project Wolpert worked on in the early 2000s was a clonal selection trial for sparkling wine he performed with the winemaking staff at Gloria Ferrer Caves & Vineyards in Sonoma, Calif. "Jim was great to work with during our Pinot Noir clonal studies," said Bob Iantosca, the executive winemaker. Wolpert worked with Sonoma County extension advisor Rhonda Smith to develop a trial block at the winery to find the clones best suited for the estate. Iantosca said the trial yielded successful, tangible results that led to another trial a few years later with clones imported from Champagne, France. "With the understanding gained from this research, there are better sparkling wines being produced—and still wines. This work would not have happened without help and direction provided by Jim." Wolpert also worked with extension viticulturist Amand Kasimatis to establish the Zinfandel Heritage Vineyard at the Oakville research station. Wolpert, Kasimatis and other extension viticulturists scoured California's oldest vineyards looking for disease-free Zinfandel cuttings. The team ultimately found 90 selections from vineyards planted before World War II. Wolpert and his team grafted the vines onto St. George rootstock and used head training to mimic the methods used by pioneering farmers of the 19th century. By using a uniform methodology, Wolpert was able to analyze the vines on specific parameters such as cluster weight, berry size and cluster tightness to identify genetic traits and isolate pure clones. In 2009, UC Davis' Foundation Plant Services released 19 selections to nurseries that came from the heritage vineyard. Zinfandel Advocates & Producers, ZAP, has donated more than $400,000 to support the vineyard, and each year a member winemaker makes wine with fruit harvested from the heritage vineyard. Chris Leamy, winemaker at Terra d'Oro winery in the Sierra Nevada foothills, made wine from the 2012 crop. Bob Biale is the co-owner of Robert Biale Vineyards in Napa, Calif., and the current president of the ZAP board of directors. He said Wolpert demonstrated the importance of capturing clonal material and the industry will "always be grateful for that." He said Wolpert's work with the heritage vineyard helped the industry by offering wineries a wider selection of Zinfandel clones, from high-yield work- Tanks 225 to 4500 Gallons QUALITY WINE ALWAYS TOP PRIORITY St. Regulus Automatic Fermentor patented managed red wine fermentation, self-pressing KiLR-CHiLR™ Temp Control managed white wine fermentation, storage, and stabilization patented ® 707-938-1300 info@acrolon.com Pioneers in Polyethylene for Wine 25 Years of Experience Thousands of Tanks in Use 208-549-1861 • www.pascopoly.com Win es & Vi n es JU NE 20 13 49