Coming off a year comprised of less than adequate growing conditions, growers, viticulturists and experts recently convened at the Napa Valley Vineyard Technical group to discuss a new vineyard issue which seems to stunt brix accumulation by as much as two degrees.

Red Blotch causes red leaves with pink/red veins on the reverse side. The reddening appears primarily at the base of the shoots.

The Napa Valley Grapegrowers is working with UC Davis to identify Napa Valley vineyards that may have red blotch. Growers there—or elsewhere—observing these symptoms in their vineyards should contact Wolpert at jawolpert@ucdavis.edu or (530) 754-6245.