Vintners tackle diseases and pests

    Smoke hangs over Del Rio Vineyards in Gold Hill. 2013 Mail Tribune file photo

    With Rogue Valley vineyards in full leaf and spring showers abating, local vintners are tackling a variety of spray and irrigation chores.

    “It seems to be a fairly normal year, we just want growers to pay attention to phenology,” said Alexander Levin, a viticulturist and assistant professor at Oregon State University’s Southern Oregon Research and Extension Center.

    Attention to detail now will most likely lead to better results in September and October when nearly 4,000 acres are expected to yield 10,000 tons of wine grapes in Jackson and Josephine counties.

    “Now is time to really expand sprays in the Rogue Valley and Applegate vineyards,” Levin said.

    Growers need to correctly identify pests — ranging from weeds, insects and disease — and how they develop in relation to the crop’s development.

    “We get questions all year long,” Levin said. “What is important is to be proactive.”

    Oregon State plant pathologist Achala KC suggests choosing fungicides that are effective on both powdery mildew and Botrytis bunch rot. Bloom time, bunch closure and ripening are critical stages for controlling Botrytis infection.”

    Rogue Valley growers will find out more about irrigation and nutrition management during Tuesday afternoon sessions at South Stage Cellars in Jacksonville.

    Levin will address irrigation scheduling, initiation and evaluation; OSU applied economics professor Beau Olen will discuss climate risk management for wine grapes; USDA researcher Paul Schreiner will explain evaluating nutrition status in grapevines; and Dave Bower of Ewing Irrigation will talk about choosing the appropriate fertilizer injector.

    “We’re trying to cover the basics of scheduling irrigation,” Levin said. “It’s always good to remind people to think about that. We want them to know about the available resources so they can figure out how much watering is needed.”

    Furthermore, factors such as cultivar, planting density, vine vigor, canopy characteristics, pest complex, and pest history are important for optimizing pest control decisions. Timing, application rate, volume of water to use in application of products, and the method of application must be considered to improve efficacy of the management measures.

    OSU’s 48-page “2018 Pest Management Guide for Wine Grapes in Oregon” covers a variety of pest-management, growth insights and organic, sustainable and integrated production resources.

    Reach reporter Greg Stiles at 541-776-4463 or Follow him on Twitter at or

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