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April 2016 WINES&VINES 17 WINE INDUSTRY NEWS the findings and continuing the research. "We have to follow up on the species and look out for the true ability of this insect to vector in a field setting as opposed to green- house conditions," he said. The discovery of a vector garnered the attention of the wine industry from a blog post by Lynn Wunderlich, the UC Coopera- tive Extension advisor for the Sierra Nevada Foothills region. Wunderlich is part of a team of advisors and researchers that has been monitoring and map- ping vineyards with a pattern of red blotch spreading. Other team members include Rhonda Smith in Sonoma County, Mike Ander- son at the Oakville research station in Napa County and virologist Mysore Sudarshana. She said she's seen evidence of the three- cornered alfalfa treehopper in the Foothills for years from the damage it can do to vine leaves. "Looking for the telltale 'single red leaf'—always with the petiole girdled—is one fairly easy way for growers to see if the treehopper is present in their blocks," she told Wines & Vines. "That said, there is much we don't yet understand about this insect and so it's really too early to give any sort of recommendation." She said pulling infected vines is still the best option to prevent the spread of the disease. "Roguing infected vines is critical to reducing spread," she said. "Most of the red blotch I've seen in the Foothills has a pattern that suggests it came in with planting material." The disease and associated virus were also the subject of one of the most well attended sessions of Wine Business Monthly's Innovation + Quality conference March 3. Moderator Celia Welch, a winemaking con- sultant in Napa Valley, said she recently was dealing with a vineyard block that just never reached its potential. The vines were not showing symptoms; the grapes reached a good Brix level, but other quality properties were lacking. Welch had the block tested and it was 90% red blotch. "I really did not want to have to face an- other vineyard crisis in my career," Welch said. "After phylloxera, after fan leaf virus, after European grapevine moth, I just thought, 'Damn it, why me? Why here, why now?' But it's around, there's no shame in it. Let's get into this, let's get it behind us." Jim Barbour, a Napa Valley vineyard man- agement consultant, described his experience with a Rutherford, Calif., vineyard that was planted in 2012. Barbour said he adopted a zero-tolerance policy to "rogue out" indi- vidual infected vines right after harvest. He added that his nursery supplied clean mate- rial free of charge for replanting. The zero- tolerance approach seemed to be working, and Barbour cautioned the audience to re- member that negative test results can be wrong on the full virus panel. Alan Wei, owner and general manager of Agri-Analysis in Knights Landing, Calif., re- minded the audience that the leafroll 3 virus is still the most damaging. Wei said that in his company's testing, more infected vines turn out to have red blotch rather than leafroll, and that red blotch has been found in wild, free-growing vines. He said the virus is graft transmissi- ble, and it appears the virus can also spread from the scion down to the rootstock. He said he hopes further research will deter- mine if the virus is spread by other vectors and what those are. Wei encouraged growers to question their grapevine suppliers in detail about their cer- tified stock, "because certified stock is sup- posed to be clean, but as many of you know, it is not always." He recommended that nurseries use a higher rate of sampling and a greater fre- quency of sampling to keep planting materials free of the virus. — Andrew Adams and Jim Gordon StaVın Inc, P.O.Box 1693, Sausalito,CA 94966 (415) 331-7849 f (415) 331-0516 stavin.com Is a barrel the only way to age a fne wine? Barrel makers would like you to believe that. They'd also prefer you not know that we've fne-tuned the art of oak infusion so deftly that in many blind tastings, experts chose our favors over wines aged in French oak barrels. Surprising, but true. If you make a special wine and are willing to think outside the barrel, now would be a good time to give us a call. ® © 2016 StaVin Inc.