Good Fruit Grower

February 15

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www.goodfruit.com GOOD FRUIT GROWER FEBRUARY 15, 2015 21 Now A Safer, More Cost Effective Alternative To Traditional Ammonia CA. . . The Frigadon HYCOOL® Secondary Refrigeration System Provides A Non-toxic CA Environment In Canada Call . . . 250-210-2015 or Email . . . info@versatilerefrigeration.com In the Northwest Call . . . 509-969-4577 or Email . . . info@versatilerefrigeration.com The Frigadon HYCOOL® Secondary Refrigeration System is designed to meet the environmental concerns of today and the future. Mechanical Access Mezzanine at Valicoff Fruit Mechanical Access Mezzanine at Valicoff Fruit t Non-toxic heat transfer fluids t Reduce insurance cost with built-in safety features t New techniques and state-of-the art technologies t Increased life expectancy of the system t Centrally located mechanical unit engineered to provide flexibility of serving several buildings t Installation costs are less expensive and require less time than complex ammonia CA facilities t Existing ammonia CA can be readily converted www.VersatileRefrigeration.com Frigadon HYCOOL® Coolers at BC Tree Fruit Coop Frigadon HYCOOL® Coolers at BC Tree Fruit Coop according to a UC Davis news release. The virus has been identified in young and mature vineyards in at least ten states, including Washington. A virus almost identical to red blotch was also found in Canada. Recent tests performed on dead vine leaves in UC Davis' Plant Herbarium show that the virus has been present in northern California's wine grape region since the 1940s, according to news reports. Symptoms of the two viruses are similar in that they both cause reddening of the leaves in red grape varietals. But a closer look at the leaves show distinct differences. Leaves infected with red blotch show a red blotchy pattern, leaf margins are flat, and veins are pink or red. Leafroll infected leaves are red, but the leaf margins roll downward, and veins are green. In white varietals for both diseases, infected leaves do not turn red but may develop a yellow chlorotic hue. The leaf margin of leafroll-infected vines will roll downward, but not those with red blotch. Growers and winemakers are concerned because the virus can significantly affect fruit and wine quality. Reduced sugar levels (up to 6° Brix) have been reported, as well as elevated titratable acidity, reduced pH, and altered tannins and phenolics. Dr. Brian Bahder, postdoctorate researcher at UC Davis, has been working on the virus since September 2013. Bahder received his doctorate in entomology in 2013 from Washington State University, where he studied grape mealybug and its impact on leafroll disease. He updated Washington grape growers with some of the latest red blotch research during the annual meeting of the Washington State Grape Society. Looking for vectors Bahder's research at UC Davis has focused on virus spread and potential vectors. The research team includes Dr. Mysore Sudarshana, U.S. Department of Agriculture research plant pathologist, and Dr. Frank Zalom, UC Davis entomologist. Red blotch virus is in the Geminiviridae virus family, said Bahder. "That's important to know because viruses in that family are often transmitted by whiteflies, leafhoppers, and treehoppers." Although Washington State University's Dr. Naidu Rayapati found that under controlled greenhouse con- ditions, Virginia creeper leafhopper could transmit red blotch virus, Bahder has not found such evidence in California. Bahder is also looking for alternate host plants for the virus. Further testing is needed on Himalayan blackberry bushes. Initially, he found positive samples for red blotch—though at low levels—in some leaves of blackberry bushes located near an infected vineyard. But when he returned to the blackberry sites in winter during dormancy, the plants tested negative for virus. COURTESY OF WASHINGTON STATE UIVERSITY A leaf from Merlot grapevine showing red veins and red blotches on margins and interveinal regions – typical symptoms of red blotch disease.

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