Washington’s Yakima Valley, a terrain of rugged hillsides and golden desert, is one of the top wine regions in the country. With an ideal climate for grapes and well-drained soils deposited by prehistoric floods, the valley is home to a third of the state’s vineyards. But the region’s many growers of wine and juice grapes face a formidable foe: the climbing cutworm. The nocturnal insect lives in vineyard soil, crawling from the ground in early spring. “The cutworm prefers to climb up the trunk and eat the buds that are swelling on the grape vine. Then the fruit’s gone,” explains Rick Hamman, viticulturist for Hogue Ranches and Mercer Estate Winery in Prosser, Washington.
Previously, Yakima Valley grape growers dealt with the cutworm threat by spraying an organophosphate insecticide that ended up killing beneficial insects while only minimally controlling cutworms. But then entomologist Doug Walsh from Washington State University in Prosser—a recipient of a research grant from the Environmental Protection Agency and American Farmland Trust—hit upon a better solution. His research team figured out they could apply a more environmentally friendly insecticide in a highly targeted fashion that avoided impacts to beneficial insects. By spraying only a banded area of the vine’s trunk rather than the entire vineyard canopy, cutworms were discouraged from climbing and destroying the fruit.
“The growers started using this solution, and it was a real cost savings to them,” says Walsh. “The grower response within two years was universal. At this point I think every grower around here has adopted this practice in some form.”
The innovation is saving Washington growers about $5.5 million a year and has reduced insecticide use by 84 percent, according to WSU researchers. “This has been great and has really helped us,” says Hamman. “It is a total success story. Doug nailed it. You can’t just sit back and do the same old thing. You’ve got to try something new.”