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Student Winemakers, Cutworm Solution

Posted by | March 20, 2008

New Course Gives Students Hands-on Winemaking Experience

WSU viticulture and enology students harvest grapes for their wine microbiology and processing class.
WSU viticulture and enology students harvest grapes for their wine microbiology and processing class.

Washington State University’s Viticulture and Enology program is looking to expand its course offerings in enology, said Charles Edwards, professor in WSU’s department of food science.

Students enrolled in the new laboratory course, Wine Microbiology and Processing, use an experiment-based facility to make wines, Edwards said. As part of the course, students travel with the instructor to the WSU Irrigated Agriculture Research and Extension Center in Prosser to harvest grapes. Grapes are brought back to Pullman where students process them under different conditions to produce red and white wines. They then perform various industry-standard analyses of their wines, including measuring ethanol content, total and volatile acidities, as well as gain experience in identifying microorganisms present during vinification.

Student winemakers not only produce red and white wines, but learn industry-standard analytical techniques, as well.
Student winemakers not only produce red and white wines, but learn industry-standard analytical techniques, as well.

Besides illustrating fermentation and processing techniques, the wines made during fall semester are used the following spring in another course, Sensory Analysis of Food and Wine. There, students learn scientific techniques and methods to identify and describe wine and its flaws using both lecture and laboratory formats. Sensory science is taught by Carolyn Ross, an assistant professor also housed in the department of food science.

The purpose of the new wine-processing course is to provide viticulture and enology students with an outstanding experience they’ll need as future leaders of and workers in the Washington wine industry, Edwards said.

–Katie Floyd, CAHNRS and WSU Extension
Marketing & News Services Intern

Extension Team Cuts Down Cutworms, Wins IPM Award

Doug Walsh examines a grape vine for signs of insect damage.
Doug Walsh examines a grape vine for signs of insect damage.

A team of WSU Extension researchers and their wine-industry collaborators have solved an expensive problem for Washington’s grape growers. The Pacific Northwest Vineyard IPM team, led by agrichemical and environmental Extension specialist Doug Walsh, and based at WSU’s Irrigated Agriculture Research and Extension Center in Prosser, devised an innovative technique that virtually eliminated cutworm bud damage on grapevines.

The vineyard solution saves growers about $5.5 million a year and has resulted in an 84 percent (about 25,000 pounds per year) reduction in pesticide use. The elegance and wide industry adoption of the team’s solution won them the 2007 Integrated Pest Management Team Award.

Previously difficult to control, Walsh said that cutworm “wakes up hungry in the spring” and immediately sets out to devour the buds where grape clusters form. Before Walsh and his team tackled the problem, treatment consisted of an organophosphate insecticide “with negative environmental consequences,” Walsh said. The organophosphate insecticide also killed beneficial insects while only marginally controlling cutworm.

Walsh’s team came up with the idea of applying insecticides in a highly targeted fashion that took advantage of the cutworm’s biology and avoided impacts to beneficial insects. By spraying a pyrethroid (rather than organophosphate) insecticide on the trunk of the vine where it meets the soil, cutworms are discouraged from climbing up from the soil where they dwell to the buds where they create damage.

The technique worked extremely well in early trials, so the challenge was adapting it to commercial-scale use. Walsh knew that herbicides were being applied to the vineyard floors with sprayers that used motion sensors that prevented the trunks of grape vines from being sprayed with damaging herbicides. Was it possible to use this technology to target the trunk instead?

“I asked a technician, ‘How difficult would it be to switch it over so that you just treated the trunk with an insecticide? And it was great. The technician leaned over, pulled out the two wires that connected it, crossed them over and plugged them back in.” The simplicity of this solution, utilizing existing technology with a twist, was a key to its rapid adoption by the industry.

“The growers started using this solution,” said Walsh, “and it was a real cost savings to them. They were using very little insecticide and getting very good control. The grower response within two years was universal. At this point I think every grower around here has adopted this practice in some form.”

In addition to Walsh, the award-winning team was composed of WSU research and Extension personnel Holly Ferguson, Ron Wight, Tim Waters and Sally O’Neal Coates. Industry collaborators were Len Welch, an entomologist with Valent USA, an agrochemical company, Leif Olsen of Olsen Wine Estates, Kevin Corliss of Chateau Ste. Michelle Wine Estates, and Sandy Halstead of EPA Region 10.