UC Davis experts: Grape growing

UC Davis has broad expertise in the area of grape growing.

Breeding and production

• Breeding pest-resistant grapevines
• Sustainable vineyard management practices
• Grape ripening
• Raisin, table and wind grape production
• Winegrape propagation and heritage zinfandels
• Screening for 'clean' plants

Water and nutrients

• Water and nutrient demands of grapevines
• Grapevines and irrigation efficiency
• Grapevine irrigation and water use
• Soil, water and vineyard management

BREEDING AND PRODUCTION

Breeding pest-resistant grapevines

Andrew Walker is a grape breeder and geneticist in the Department of Viticulture and Enology. His research is focused on developing new grape rootstocks with resistance to destructive vineyard pests, including the fanleaf, dagger and root-knot nematodes, and grape phylloxera. His lab studies the genetics of resistance to these pests, and the pests' genetic diversity, aggressiveness and interactions with the grape species they infest. His lab also is actively involved in breeding wine, table and raisin grapes for resistance to Pierce's disease and powdery mildew. He holds the Louis P. Martini Endowed Chair in Viticulture. Contact: Andrew Walker, Department of Viticulture and Enology, (530) 752-0902, .

Sustainable vineyard management practices

Kerri Steenwerth is a U.S. Department of Agriculture research soil scientist in UC Davis' Department of Viticulture and Enology. She is applying her expertise in plant and soil microbial ecology to study how various farming techniques for managing the vineyard floor impact weed management and soil-nutrient dynamics. Her research program is focused on identifying and implementing sustainable farming practices that minimize inputs and reduce costs related to weed management, while improving soil function, nutrient retention and grapevine health. Current research studies are related to the effect of cover crops and vineyard tillage on soil microorganisms, soil carbon and nitrogen dynamics, seed germination of vineyard weeds and herbicide resistance in vineyard weeds. Contact: Kerri Steenwerth, Viticulture and Enology, (530) 752-7535, .

Grape ripening

Douglas Adams is an associate professor and associate biochemist whose research program focuses on grape berry ripening. He has concentrated his efforts in two principal areas: the biochemical changes that occur during ripening, and the development of tannins in skins and seeds of red wine varieties. His most recent work on tannin development during ripening has led to the development of the Adams-Harbertson Phenolics Panel for the analysis of tannins and polymeric pigments in grapes and wines, which is currently available commercially. His lab's second project is directed at identifying genes involved in grape berry ripening. More information is available at: http://wineserver.ucdavis.edu/adams/tannin/index.htm. Contact: Douglas Adams, (530) 752-1902, .

Raisin, table and wine grape production

Matthew Fidelibus is a Cooperative Extension viticulture specialist with the Department of Viticulture and Enology, stationed at the UC Kearney Agricultural Center near Fresno. Through research, he is working to develop new production methods, and to refine existing ones so that the yield and quality of raisin, table and wine grapes is improved. An example of his recent work on raisins is the discovery that grapevine cultivars, canopy management practices and drying methods interact to affect the quality and consumer acceptance of raisins. For table grapes, he showed how a natural plant growth regulator, abscisic acid, could best be used to improve the color of red grapes. In wine grapes, he has identified the best selections of cabernet sauvignon, chardonnay, merlot and zinfandel for Central Valley growers. Contact: Matthew Fidelibus, Kearney Agricultural Center, (559) 646-6510, .

Winegrape propagation and heritage zinfandels

James Wolpert is a Cooperative Extension viticulture specialist in the Department of Viticulture and Enology. His research program is focused on evaluating wine grape rootstocks and clones, which are groups of vines propagated from a single parent vine. He also conducts educational programs for wine-grape growers in Northern California. Over the past decade, Wolpert and colleagues have identified and collected selections of zinfandel grapevines from old vineyards, many dating to the end of the 19th century or early 20th century. The project, carried out in partnership with the Zinfandel Advocates and Producers, is intended to conserve potentially valuable zinfandel selections that are at risk of being removed so the grower can plant newer, more productive vineyards. It also is intended to identify selections with better winemaking attributes, including color and varietal character, and looser grape clusters that are less prone to rotting. The Department of Viticulture and Enology's Zinfandel Heritage Vineyard at its Oakville vineyard in the Napa Valley now contains a unique "library" of 84 zinfandel selections, representing 52 vineyards from 14 counties throughout California. Contact: James Wolpert, Viticulture and Enology, (530) 754-6245, .

Screening for 'clean' plants

Deborah Golino is a Cooperative Extension plant disease specialist and director of UC Davis' Foundation Plant Services, which is dedicated to providing commercial nurseries with healthy plants that are also accurately identified. The service is responsible for screening programs for grapes, strawberries, fruit trees, nut trees, sweet potatoes and roses. It is the major importation program for grapevines in the United States, where new varieties and clones pass through quarantine before they are released to the grape industry each year. Golino also manages a research program focused on controlling viruses and virus-like diseases of grapevines. That research is intended to improve methods for detecting disease-causing microbes and eliminating viruses from plants. Contact: Deborah Golino, Foundation Plant Services, (530) 752-3590, .

WATER AND NUTRIENTS

Water and nutrient demands of grapevines

Mark Matthews is a professor and environmental plant biologist whose research is directed toward helping viticulturists to improve water and nutrient use by better understanding the water and nutrient needs of their vineyards and the consequences for yield and quality. As part of his long-term research program aimed at improving the use of water and other limited resources, he studies how plants interact physically and chemically with their environments. His more fundamental research has focused on water transport, cell expansion and gas exchange within the plant. On the practical side, he focuses on improving the ability to identify and regulate the status of grapevines with respect to water and nutrients, as well as cataloging the consequences of resource limitations for growth and development of grapevines. More information about the Matthews laboratory and its research program is available online at http://matthews.ucdavis.edu/home.html. Contact: Mark Matthews, Viticulture and Enology, (530) 752-2048, .

Grapevines and irrigation efficiency

Andrew McElrone is a U.S. Department of Agriculture research plant physiologist associated with the UC Davis Department of Viticulture and Enology. His research on grapevine water use in California vineyards is aimed at improving water-use efficiency. This is particularly important in the many growing regions where demands for irrigation water are increasing and the quality of available water is decreasing. He is studying how grape rootstocks transport water and how the flow of grapevine sap can be evaluated to measure the vine's overall water use. He also is assessing how vineyard-floor farming practices affect grapevine water use and fruit quality. Contact: Andrew McElrone, Viticulture and Enology, (530) 754-9763, .

Grapevine irrigation and water use

Larry Williams is a plant scientist in the Department of Viticulture and Enology, stationed at the UC Kearney Agricultural Center near Fresno. His research focuses on irrigation and fertilization management in vineyards. He has conducted irrigation experiments on wine grapes in Madera, Napa, Monterey, San Luis Obispo and Santa Barbara counties; on table grapes in Fresno and Riverside counties; and on raisin grapes at the UC Kearney Agricultural Center. These studies are aimed at determining how much water vines will use under nonstressed conditions and the effects of deficit irrigation on productivity and fruit quality. The resulting data will be used to help grape growers schedule the timing of irrigations and the amount of water that should be applied. His lab also studied water needs of native grapevines in hopes of helping grape breeders develop drought-tolerant rootstocks. Contact: Larry William, UC Kearney Agricultural Center, (559) 646-6593, .

Soil, water and vineyard management

Jean-Jacques Lambert, a soil scientist in the Department of Viticulture and Enology, studies nutrient and water availability in different viticultural soils, soil solution chemistry changes in the root zone during the growing season, and nutrient and water uptake by grapevines on different sites. His current research projects include studies on the impact of soil variability
on vine growth parameters and grape and wine quality within single vineyards; the effects and sustainability of long-term use of saline irrigation water on different rootstocks planted on various soil types in the Central Coast area; and the impact of soil heterogeneity on water use and vineyard management practices of the San Joaquin and Sacramento deltas.
Contact: Jean-Jacques Lambert, (530) 754-9875, .

Media contact(s):

• Pat Bailey, UC Davis News Service, (530) 752-9843,

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