Current Viticulture & Enology Research
For more information, please click on the name of the researcher to go to their home page.
For a list of current V&E Faculty, please click here.
Bhaskar Bondada, Ph.D. 
This research program addresses industry goals through the use of integrative plant physiology and plant anatomy. The program utilizes the knowledge of structure-function relationships to improve vine health and fruit quality. More specifically, our lab investigates ampelography and cultivar identification, water relations of grapevine and berry, developmental anatomy of grape berry, ecophysiology of water stress, and hydraulic architecture of grapevine and berry. We investigate the above research goals using light, confocal and electron microscopy in combination with contemporary approaches adopted to study the physiology of the plants.
Carter Clary, Ph.D.
Areas of Interest
- Microwave Vacuum Dehydration (MIVAC)
- Production, Harvesting , and Handling of Fruits and Vegetable.
- Application of Dehydration Technology
Ken Eastwell, Ph.D.
Current Program:
- Reducing the economic impact of virus diseases of vegetatively propagated perennial crops including fruit trees, grapevines, hops, and flower crops.
- Development and evaluation of microbial agents to protect crops from disease.
Current Projects (related to grapes):
- Development of biocontrol agents to protect grapevines from crown gall disease.
Charles Edwards, Ph.D.
Wine Microbiology 
Sluggish/stuck alcoholic fermentations
Generally, wine yeasts grow rapidly in grape juice despite high concentrations of sugar and sulfur dioxide as well as low pH. Occasionally, however, the alcoholic fermentation can prematurely stop or stick due to a number of factors. While nitrogen deficiencies in musts can lead to some of these problems, a lack of vitamins may also be of concern. Our laboratory is currently studying the impact of these vitamins on rate of fermentation and wine quality. Washington State. As part of the laboratory effort, yeast growth, fermentation rate and production of volatile compounds like hydrogen sulfide are being measured.
Dr. Edwards is author of the recently published book, "Illustrated Guide to Microbes and Sediments in Wine, Beer, and Juice." This reference book is intended to be a practical guide for the microscopic analysis of beverages.
It features photographs of microorganisms typically found in juices, wines, and beers as they appear under the microscope and as colonies on solidified agars. Dr. Edwards is also co-author on the upcoming second edition of Wine Microbiology (2006).
Brettanomyces
The laboratory team of Dr. Edwards is currently working with strains of Brettanomyces yeast isolated from wineries in the Pacfic Northwest. Brettanomyces is an infection of red wines that can spoil a wine through formation of very “stinky” molecules, primarily volatile phenols (4-ethyl phenol and 4-ethyl guiacol). Much research remains such as determining the mechanism for inducing this state as well as how cells regain culturability.
Wine Chemistry
As part of WSU collaborative effort in wine research, our program helps perform analysis of musts and/or wines produced from viticultural research experiments conducted at the experiment station in Prosser and other locations in Central Washington. Research is on-going studying (a) influence of viticultural practices on chemical composition of musts and (b) relationships between species/strain of wine microorganisms and synthesis of compounds important for quality.
Gary Grove, Ph.D.
Research Specialty and Interests:
Epidemiology and management of fungal diseases of stone fruits, grapes, hops, ornamentals, and raspberries
Extension Interests:
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Web-based extension education (http://fruit.wsu.edu; http://hops.wsu.edu)
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Podcasts & iPod video
- Applications for PDA's
David James, Ph.D.
INTEGRATED AND SUSTAINABLE INSECT AND MITE MANAGEMENT
Research on viticultural entomology at WSU is focused on developing and delivering optimal pest management that is sustainable, cost-effective and based on biological control. Our principal aim is to reduce pesticide usage and costs, replacing them with the free pest control services provided by endemic predators and parasitoids. Recent research projects have improved our understanding of biological control of leafhoppers and spider mites and allowed growers to adopt strategies which capitalize on this natural pest control. As a result of these and other projects, broad-spectrum pesticide use in Washington grapes has declined significantly since 2000.
Currently, our major research initiative involves exploring the potential of using methyl salicylate (MeSA) (a common component of toothpaste and candy), to ‘tell’ grapevines to scream for ‘bodyguards’, or the natural enemies of grape pests. Grapevines have evolved over millennia to produce a complex bouquet of volatile chemicals or odor signals (which includes MeSA), when they are attacked by leafhoppers, mites, mealybugs etc. These distress signals are used by predators and parasitoids to locate their prey, ie, grape pests. They are also ‘heard’ by adjacent grapevines which then produce their own predator-attracting volatiles. Field data collected during the past few seasons have shown that by placing controlled-release dispensers of MeSA in vineyards we can recruit greater numbers of beneficial insects and improve biological control. While the details of mechanisms etc remain to be worked out, it appears that MeSA provides us with a tool for communicating directly with grapevines, telling them to ‘turn on’ their defenses!
Other research projects address other important viticultural pest issues like mealybugs and their role in vectoring leaf roll virus, the recent emergence of rust and bud mites as significant grape pests in Washington and the biology and management of cutworms.
James Harbertson, Ph.D.
Research interests are focused on the phenolic compounds found in grapes and wine and their biochemical and chemical changes during grape ripening, winemaking and aging. Example projects include understanding the variability of tannin found in red wine cultivars and the ultimate relationship between tannin, polymeric pigments and astringency. Works with wineries to solve simple and difficult problems and is located in the wine-grape growing region at the WSU Prosser Irrigated Agriculture Research and Extension Center.
Markus Keller, Ph.D. 
Dr. Keller's research program focuses on developmental and environmental factors and vineyard management practices as they influence crop physiology of wine and juice grapes. His lab investigates scion-rootstock interactions, grape development and water relations during fruit ripening, irrigation and crop load management, yield formation, and cold hardiness. In addition, the program makes clean grapevine selections available to industry and research through the Northwest Grape Foundation Service and provides an important industry service in monitoring cold hardiness throughout the winter season.
Manipulating grapevine bud temperature in spring results in dramatic differences in shoot vigor
Mercy Olmstead, Ph.D.
Use of Cover Crops to Attract and Retain Beneficial Insect Populations
This research is being conducted in cooperation with Dr. David James and Dr. Tessa Grasswitz in order to identify cover crops that help to attract and keep beneficial insects in the vineyard. This research is currently going into its second of three years, and will focus on verifying data collected this past growing season. Flowering cover crop mixes look promising; however can be expensive to sow annually.
Irrigation Practices in Washington State Vineyards
In order to identify irrigation practices currently used in wine and juice grape vineyards, a survey was conducted and distributed online and through the WSU Viticulture and Enology Research andExtension Newsletter. With 1/3 of the wine grape acreage and some juice grape acreage reporting, the main irrigation 
system used in Washington State is drip irrigation, followed bysprinkler and furrow irrigation. While wine grape vineyards used drip irrigation systems more readily, juice grape vineyards irrigated grapes with sprinkler and furrow systems. This study also looked at correlations with irrigation practice and berry shrivel; however, no link was identified. Growers are aware of different irrigation strategies but need more information on implementation in the vineyard.
Nutrition Deficiency and Impact on Grape Production
Grape nutrient deficiency can negatively affect grapevine growth and fruit quality; however the research and grower community lacks a comprehensive guide to identify macro- and micronutrient deficiencies. In collaboration with Dr. Joan Davenport, research is being conducted that will aid scientists and growers in identifying single and multiple nutrient deficiencies in addition to identifying appropriate nutrient levels for major macro- and micronutrients.
Naidu Rayapati, Ph.D.
Diversity of grapevine viruses
Increased level of knowledge on the incidence and prevalence of grapevine viruses is critical for mitigating their negative impact on the sustainability of viticulture industry and in maintaining the sanitary status of vineyards in Washington State. Research on biological and molecular characterization of viruses associated with economically important diseases of the grapevine is being carried out with funding support from the USDA Northwest Center for Small Fruits Research and Wine-Grape Funds from Washington State.
Molecular biology of grapevine viruses
Grapevine leafroll disease is one of the most complex virus diseases. At least nine different viruses, termed grapevine leaf roll-associated viruses (GLRaVs), have so far been found associated with the disease. In addition, GLRaVs represent one of the few groups of plant viruses with complex genomes and many biological intrigues. We are collaborating with Dr. Bill Dawson and Dr. S. Gowda at University of Florida , Citrus Research and Education Center, Lake Alfred, to understand various aspects of the biology and molecular biology of GLRaVs.
Epidemiology of grapevine leafroll disease
Grapevine leafroll disease is a major concern for the sustainability of viticulture in Washington State. Therefore, the long term goal of this project, developed in response to wine industry’s research priorities, is to have a better understanding of the epidemiology of GLD in Washington State vineyards in order to develop appropriate control strategies. This research, funded by the Northwest Center for Small Fruits Research and Wine Grape Funds from Washington State, involves optimizing sampling strategies for reliable detection of viruses, analyzing spatial distribution and various means of spread of the disease.
Outputs from this research is being utilized in virus-indexing programs funded by Washington State Department of Agriculture through Nursery Assessment funds and Washington Sate Commission on Pesticide Registration to facilitate propagation of virus-tested grapevines by the Northwest Grape Foundation Service and Certified Nurseries in the state.
Ekaterini Riga, Ph.D.
Research Specialty and Interests:
- To control plant parasitic nematodes using organic amendments, cover crops, green manures, organic nematicides and a combination of low rates of synthetic nematicdes with organic amendments
- To understand the role, behaviour and physiology of free-living nematodes in the soil environment and use them as means to restore soil health
- To develop molecular markers for nematode identification
- To use entomopathogenic nematodes as biological control agents against insects
Carolyn Ross, Ph.D.
Dr. Ross's research combines sensory analysis with analytical chemistry techniques to identify and describe changes in flavour and odour profiles. In grapes and wine, her research group focuses on evaluation of aroma and flavour compounds and precursors, and the changes in these compounds due to viticultural and enological practices.
Dr. Ross’s research group is conducted research in numerous areas of wine sensory evaluation. Studies include:
- Comparison of the effectiveness of different fining agents on the chemical and sensory properties of Washington State Chardonnay and Gewurtztraminer
- Examination of astringency in Washington State red wines and the resulting perception of astringency
Willingness of consumers to purchase wines of different astringency values - Effectiveness of different palate cleansers at reducing astringency carry-over between repeated sips of red wine
- Effect of serving temperature on sensory perception in red and white wine
- Examination of off-odours in Concord grape juice and wine due to lady beetle taint
Julie Tarara, Ph.D. - USDA-ARS
The viticulture program based in Prosser, WA works toward developing better farming practices in vineyards by studying the effects of the physical environment (sunlight, temperature, wind, humidity) on grapevines.
Because plants cannot move themselves away from an undesirable environment (unlike us, they can't sit in the shade or put on another sweater), it is important to understand how the environment affects grapevine biology, which we pursue by conducting experiments in vineyards in conjunction with plant physiologists and other biologists. 
With this knowledge, grape growers may have the opportunity to modify the environment around the vine or within the vineyard with adaptations to things like trellising, irrigation, soil cover, or other farming practices intended to keep the vines in the most favorable microclimate for the production of high-quality grapes.
For more information on the USDA-ARS Grape and Wine Program: http://www.ars.usda.gov/is/video/vnr/grapes.htm
Doug Walsh, Ph.D.
Current Projects:
Wine grapes/ cutworms |
Jack Watson (WSU Benton County) |
Wine Advisory Committee |
Wine grapes/ mealy bugs |
Ken Eastwell (WSU Plant Pathology) David James (WSU Entomology) |
Wine Advisory Committee & Washington State Commission on Pesticide Registration |
Kathleen Williams, Ph.D.
My research program consists of undergraduate teaching assessment studies (with Cathy Perillo and Teresa Koenig) and the "Virtual Vineyard" computer project for undergraduate courses in Viticulture. Currently, Kathryn House is completing her M.S. in Hort. with part of her thesis involving the "Virtual Vineyard".
Areas of Interest
- Small fruit and grape physiology
- Grape production and management systems
- Plant bioregulators
- Distance education
Currently Teaching
- Hort 313 Introduction to Viticulture and Small Fruit Production
- Hort 413/513 Advanced Viticulture
- Hort 509/510 Graduate Seminar (Alternate Years)
- Hort 102 Cultivated Plants (with Teresa Koenig)
Soils Research
Joan Davenport, Ph.D.
This research program focuses on soil fertility and plant nutrition in for both annual and perennial crop plants grown in irrigated systems. Specific areas studied are: soil and crop production and quality information to advance precision farming practices; nitrogen management strategies to maintain and enhance both crop and environmental quality; crop response to changing macronutrient management.
Chlorosis in 
a Concord Vineyard
CURRENT PROGRAM:
- Nutrient partitioning and distribution in Concord grape
- Nutrient management in juice and wine grape
- Development of tissue nutrient standards for irrigated wine grape in the Pacific Northwest
- Compost effects on wine grape vineyards
- Evaluating legume cover crops as an organic nitrogen source in Concord grape
- Understanding and alleviating Concord chlorosis
Whole Plant Sampling (Concord) for Nutrional Analysis