James A. Wolpert, Ph. D.
Viticulture and Enology
Dr. Wolpert joined the Department of Viticulture and Enology in 1985. As an Extension Specialist, he was responsible for applied research and grower education programs for northern California. He had two focal points to his research: evaluation of winegrape varieties and clones and the evaluation of rootstocks. Choice of both scion and rootstock are critical decisions in vineyard establishment. His work in rootstock evaluation throughout northern and coastal California has provided the basis for grower recommendations for a range of soil types. Clone selection decisions are complex and involve marketplace targets, 'wine quality,' and other subjective considerations. His clonal evaluations included work on Chardonnay and Pinot noir for sparkling wine, as well as Cabernet Sauvignon, Merlot, Malbec and Zinfandel, allowing growers some insight into making those difficult decisions. Dr. Wolpert, with several UC farm advisors and emeritus specialist A. Kasimatis identified and collected selections of Zinfandel from old vineyards, many dating to the end of the 19th century or early 20th century. The project had two goals: 1) conserving potentially valuable selections that are at risk from economic pressures to replant to newer, more productive vineyards, and 2) identifying selections with better winemaking attributes (better color and varietal character, and looser, less rot-prone clusters). The Zinfandel Heritage Vineyard at the department's Oakville Station vineyard in Napa Valley investigated viticultural and enological characteristics of advanced selections of Zinfandel taken from their original collection.