UCD Professor/Geneticist to Retire June 29 June 02, 2021
University of California, Davis (UCD) professor and geneticist Dr. Andrew Walker will retire June 29 after more than 30 years on the Department of Viticulture and Enology faculty and as a winegrape breeder. Given the long-term nature of the grape breeding process, it s not surprising that some of Walker s more significant breeding projects came to fruition later in his career the release of five nematode resistant rootstocks in 2009, and the 2020 official release of five new winegrape varieties resistant to Pierce s Disease (PD). Reflecting the reality of his work, Walker titled one of his recent lectures, 30+ Years of Grape Breeding and Just Getting Started. With additional winegrape cultivars in development in the Walker Lab being bred for both PD resistance and powdery mildew resistance, important new grapevine materials will continue to become available well after he retires.
Pasaente Noir at The Ojai Vineyard / Photo by Kim Baile
Losing a vineyard to disease is “extremely painful,” says Adam Tolmach, cofounder of The Ojai Vineyard. In 1981, he planted more than five acres of mostly Syrah on Ventura County land that his grandfather purchased a half-century earlier. His last vintage was in 1995.
“You put your heart and soul into it,” says Tolmach. “I planted every one of the vines and nurtured them. It was like my baby that I was working on. It was very heartbreaking to have it slowly die off.”
The culprit was Pierce’s disease (PD), which is spread by insects known as glassy-winged sharpshooters. It’s one of the few scourges that actually kills vines, rather than just hamper them. A problem in California since the dawn of commercial grape-growing in the 1880s, PD is more prevalent in Southern California. But it’s also known to hammer vines in the north, especially along riparian corridors like those near the Napa River.
Upper left, Molly Scott, Justin Vineyards and Winery; upper right, Adam Tolmach, Ojai Vineyard; lower left, Chuck Wagner, Caymus Vineyards; and lower right, Andy Walker, University of California, Davis.
The Unified Grape and Wine Symposium is always a great place to try wines from all over the country. This year’s conference, while it was held virtually, nevertheless presented a tasting event to address the concept that while the world is changing, the vinifera varietals grown in California have remained the same. Winegrowers are dealing with climate changes, different consumer preferences and market conditions, labor availability, and a changing regulatory environment. In spite of these challenges, many growers have resisted planting new varieties of grapes.