Napa Valley's Grape Growers Struggle to Detect and Contain Red Blotch Disease

By Brett Marsh, Napa Register

​Signs of red blotch infection on a grapevine, U.S. Department of Agriculture/Courtesy photo

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"​A stubborn grapevine disease is confounding the Napa Valley’s wine grape growers. Its symptoms – red, blotchy patterns on the leaf – almost look like benign fall colors.
But red blotch, as the virus is called, has emerged as one of the most damaging and difficult-to-track grapevine diseases to hit the valley in years. And its center is the Rutherford American Viticultural Area – known for generous sunshine and cool evenings, home to some of Napa’s oldest and most renowned vineyard properties. 
Vineyard managers Jake Maus and Brian Hoefgen have been on the front line of the battle against red blotch since it was identified by UC Davis researchers in 2012. Maus has been with Colinas Farming Co., which manages vineyards across multiple AVAs, since 2015, while Hoefgen runs Beckstoffer's Georges III Vineyard, a 300-acre parcel in Rutherford..."

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