Projects at the UC Davis Oakville Vineyard
The Robert J. Barone Laboratory helps to make our research projects possible.
In 2003, the Robert J. Barone Laboratory was utilized by Felipe Laurie, a viticulture and enology Ph.D. candidate, in a cooperative project with Harlan Winery. The team's goal was to assess the evolution of winegrape phenolic compounds during ripening. Winemakers have traditionally looked at sugar content and acid profiles, known as primary metabolites, as the key quantifiable parameters determining winegrape maturity. However, the emphasis has shifted to closer examination of secondary metabolites, such as phenolic and flavor compounds, as more indicative of true winegrape maturity. This new research is especially important to the industry as we struggle for a practical methodology that can be universally accepted to quantify these critical components of red winegrape maturity.
Dr. David Smart, Assistant Professor in the Department of Viticulture and Enology, and Assistant Plant Physiologist in the UC Agricultural Experiment Station, has two ongoing projects taking place at Oakville. The first project's goal is to determine the impact of a select vineyard cover crop on both above-and below-ground carbon content. The increase in carbon dioxide in the atmosphere, as a direct, primary consequence of fossil fuel consumption and land clearing, is the major contributor to global temperature increase and shifts in seasonal precipitation patterns. These changes have direct consequences on agricultural practices - in particular for winegrape production, a crop where issues of quality are directly affected by subtle environmental changes. The use of cover crops could potentially increase long-term sustainability and health of vineyard soils, improve control of water to the vine and, thus, increase winegrape quality and resultant wine quality. The second project seeks to develop an understanding of the behavior of vine roots under a number of irrigation regimes, fertilization applications and types of rootstock and the impact of these variables on both yield and winegrape quality. This is a collaborative effort between UC Davis and Penn State University, currently in its third year. It is especially important because regulated deficit irrigation is known to decrease foliar vigor while improving red winegrape quality with minimal yield loss. But little is understood about the impact of this practice on root physiology and, thus, on nutrient availability and long-term viability.
David Mills, Assistant Professor in the Department of Viticulture and Enology, and Assistant Microbiologist in the UC Agricultural Experiment Station, is currently engaged in a joint project with Far Niente Winery. This research studies the yeast, bacterial ecology and diversity in a late harvest, botrytised Semillon/Sauvignon blanc juice over the period of a prolonged fermentation. The organisms are grown and analyzed both traditionally, on selected media and with newer molecular techniques.
Jim Wolpert, Chair of the Department of Viticulture and Enology and a specialist in Cooperative Extension, conducts a number of trials at our Oakville facility. Most of Dr. Wolpert's current Oakville research emphasizes the influence of various cultural practices and strategies on vine performance and, ultimately, winegrape quality. These cultural practices include rootstock selection, clonal selection, training or trellising choices and both in-row and between-row spacing choices. As such, these are all ongoing, long-term studies with potential significant commercial impact. Dr. Wolpert's work also includes the maintenance and expansion of the famous Heritage Zinfandel collection, which was established in 1989. Described as a "vibrant `ongrowing' museum of the zinfandel grape," the vineyard is an unusual and unprecedented collection of rare Zinfandel vine cuttings from all over California. The 1.1-acre vineyard includes a total of 90 selections from 14 counties in California. The goal of the Heritage Vineyard, according to Jim Wolpert, is to "help the industry discover answers to some of the mysteries surrounding Zinfandel and to preserve the special qualities of the old vines for future generations." Not only is the vineyard of tremendous historical and viticultural interest, it also has a special significance for the wine and grape growing industry because it represents a resource for future plantings of Zinfandel with a broad range of selections.
Napa County farm advisor Ed Weber and Sonoma County farm advisor Rhonda Smith are conducting a study on berry shrivel. Berry shrivel has had a serious impact on many vineyards in the last several years, yet its mechanisms are poorly understood. Weber and Smith's research seeks to determine the cause of berry shrivel, discover whether its source might be environmental or due to a nutritional imbalance, and investigates the effect of cultural practices and management strategies.
The Hilgard Project is administered by Roger Boulton, Associate Professor of the Department of Viticulture and Enology and the Department of Chemical Engineering and Materials Science, and Chemical Engineer in the Agricultural Experiment Station The Project is the application of an advanced measurement and control system and an efficient historical archive database to the measurement of research, teaching and management properties in the vineyards and wineries of the Department of Viticulture and Enology, at the University of California, Davis. Future plans include the establishment of an extensively instrumented reference vine at Oakville, (known as the "Wired Vine"); the gathering of data from all vineyard experiments and weather stations; and the measurement of irrigation system performance at the Oakville vineyards.