For 2017-2018, the OWB allocated $350,000 for the support of these research grants. Investigators are just beginning their research for the 2017-18 year. Updates on the projects will be reported throughout the year. Below are summaries on what each investigator will be researching and what they hope to find.

Laurent Deluc, Associate Professor, Department of Horticulture, Oregon State University.
Determine the role of Auxin-Response Factor 4 (ARF4) in the timing of ripening initiation in Vitis vinifera.

Changes in the climate are expected to influence not only the practices in the field, but also organoleptic characteristics of the wine. In order to anticipate such events there is a need to better understand the process of the ripening program in grapevine. In our lab, we are currently studying the connection between the timing of ripening initiation, also named véraison, and the activity of genes. We believe we have identified one of these genes that could influence when the fruit enters the ripening process. Characterizing the function of this gene (ARF4) and how environmental factors and genetic makeup influence its activity will be of great interest in the perspective of developing innovative practices and new methods to identify new clones/cultivars more amenable to sustain any local changes in the Oregon climate in a near future.

Alexander D. Levin, Department of Horticulture and Oregon Wine Research Institute, Oregon State University and Southern Oregon Research and Extension Center.
Determination of pre- and postveraison water status targets for deficit irrigation of Pinot noir in a warm climate.

Most new vineyard plantings in the Southern Oregon AVA have been to Pinot noir, the state’s signature red wine grape variety. Because Pinot noir is traditionally grown in mild climates, local growers lack information regarding its performance in arid climates. This project aims to fill the knowledge gap by imposing various deficit irrigation treatments in a commercial Pinot noir vineyard and monitoring aspects of vine growth and development. Additionally, experimental wines will be produced and subjected to sensory analyses. In this way, local growers will be able to optimize their irrigation management practices to improve yield and quality, while simultaneously saving water.

Walt Mahaffee, Research Plant Pathologist USDA-ARS-HCRL.
Lindsey Thiessen, Department of Botany and Plant Pathology, Oregon State University.
Grape powdery mildew management—A fungicide timing and selection conundrum.

This research will improve the efficiency of grape production by optimizing fungicide selection and timing to manage powdery mildew of grape berries. Data from two years of field trails indicate that using mobile fungicides chemistry and application late bloom to early fruit set results in better disease control on berries. In 2017, commercial scale demonstration trails are being conducted at the block scale. This research will determine the most effective fungicide application timing with relation to grape inflorescence development/phenological stage and how their mobility impacts disease development.

James Osborne, Extension Enologist, Department of Food Science and Technology, Oregon State University.
Impact of pre-fermentation cold soak conditions on microbial populations and consequences for wine aroma.

During the cold soaking process, the growth of various yeasts can positively or negatively impact wine quality depending on the yeast species present. This research investigates how cold soak conditions such as temperature, SO2, and yeast diversity could be manipulated by a winemaker to encourage or discourage growth of certain yeast to improve wine aroma. Pinot noir wines were produced from grapes cold soaked for six days at 6 or 10 deg. C with the addition of 0, 50, or 100 mg/L SO2. The wines contained significantly different concentrations of many key wine aroma compounds and had increased color compared to wine produced from grapes that were not cold soaked. Increasing SO2 concentration was more effective at reducing yeast populations than lowering temperature with most cold soaks being dominated by the spoilage yeast Kloeckera apiculata. Further experiments demonstrated that the addition of certain commercial non-Saccharomyces cultures at the beginning of the cold soak can retard the growth of K. apiculata and reduce the production of acetic acid and ethyl acetate. This may be an additional tool for winemakers to utilize to minimize the development of volatile acidity during a cold soak, particularly in years with a higher proportion of damaged grapes where populations of K. apiculata in a cold soak can be high.

Ron Runnebaum, Assistant Professor, Department of Viticulture & Enology, University of California Davis.
Clonal evaluation of grape powdery mildew resistance in a heritage Pinot noir clone and comparative wine fermentation, chemical and sensory analysis.

Plant pathogens are one of the major challenges of viticulture. Wrotham Pinot noir, a little-known clone brought to the U.S. from England by winemaker Dick Peterson in the early 1980s, has been observed to exhibit grape powdery mildew (PM) resistance. This Pinot noir clone has been used to produce both high quality still and sparkling wine. The goal of this project is three-fold: 1) examine the clone’s phenotypic PM resistance to multiple PM strains; 2) compare the microsatellite DNA of the clone to known Pinot noir clones; and 3) compare the wine chemical and wine sensory profiles, as well as the fermentation rates, of Wrotham Pinot noir to known Pinot noir clones. This research is a collaboration of Andrew Walker, Dario Cantu, and Ron Runnebaum of University of California at Davis.

Paul Schreiner, Research Plant Physiologist, USDA-ARS-HCRL and OWRI.
Comparing nitrogen fertilization in the vineyard versus supplementation in the winery on quality of Pinot noir and Chardonnay wines and productivity in the vineyard.

This research addresses the fundamental issue of whether wine quality can be enhanced more effectively by boosting vine nitrogen status via fertilization or by maintaining lower vine nitrogen status in the vineyard but boosting must nitrogen in the winery. This work is being conducted in both Pinot noir and Chardonnay, as we suspect that red wine quality and white wine quality may differ in response to nitrogen manipulation. The Oregon wine industry will benefit by understanding how to best manage nitrogen inputs to create optimal wines, maintain productivity, and reduce the environmental impact of wine production.

Patty Skinkis, Associate Professor and Viticulture Extension Specialist, Department of Horticulture, Oregon State University.
Statewide crop load project: A researcher-industry partnership to understand the yield-quality relationship in cool climate Pinot noir and Chardonnay production.

Yield is a quality control factor in premium wine regions, and it is achieved by cluster thinning vineyards to finite tonnage goals. This research employs multiple methods to understand the effect of yield, crop load and vigor on fruit composition and wine quality while documenting how management decisions are made by industry collaborators using data from on-site trials. This project is being conducted in 12 Oregon vineyards and across multiple seasons to exploit site and vintage variability to develop yield management guidelines under different conditions and production goals.