For the 2021-22 fiscal year, the OWB is funding $289,000 in Viticulture and Enology research grants. Below are the six funded projects. Updates on these projects will be reported throughout the year.
Variations of Berry Size
Federico Casassa, Associate Professor of Enology, Wine & Viticulture Department, California Polytechnic State University, San Luis Obispo.
Berry size is seen as a determining factor of wine quality because excessive berry size (due to varietal or viticultural practices) may lead to a proportional decrease of solids (skins and seeds) where sensory-relevant compounds are located. Here we aim to understand the effect on wine chemistry and sensory aspects due to intrinsic variations in berry size on V. vinifera L. cv. Pinot noir as well as to explore winemaking practices to manipulate berry size during winemaking. The understanding gained from this project will assist Oregon winemakers in clonal selection and winemaking techniques in Pinot noir for management of berry size related chemistry and sensory aspects.
Grapevine Trunk Diseases in Oregon Vineyards: A Pilot Project on Epidemiology and Management
Achala KC, Plant Pathologist and Assistant Professor, Department of Botany and Plant Pathology and Southern Oregon Research and Extension Center, Oregon State University.
A pilot project on epidemiology and management of Grapevine Trunk Diseases (GTDs) was started in Oregon vineyards in 2019. We surveyed 29 vineyards for symptoms and installed two spore traps each in northern and southern Oregon. In addition to common GTD-causing pathogens, we isolated other pathogens that cause Esca and trunk diseases. In preliminary spore trapping results, we are finding that the spores of pathogens causing Botryosphaeria dieback starts sometime in mid-December in Willamette Valley. At the end of this project, we hope that the Oregon wine industry will benefit from local-level information on GTDs and management practices to address them accordingly.
Project reference: 2338_GTD management OR Pilot
Determining Optimal Irrigation Initiation Time
Alec Levin, Viticulturist and Assistant Professor, Southern Oregon Research and Extension Center and Department of Horticulture, Oregon State University.
When to initiate irrigation is a critical annual management decision that has a large impact on the current season’s grape production. Delaying irrigation initiation can have many positive direct and indirect effects on grapevine growth and development, and ultimately on fruit and wine quality. Thus, it is economically favorable to delay the initiation of irrigation just enough to create a slight water deficit. The overall objective of this proposed research project is to determine the optimal irrigation initiation time by delaying initiation time using declining stem water potential thresholds, and relating crop yield and quality metrics to those thresholds. Our central hypothesis is that growers can substantially delay irrigation initiation time without any negative effects on current or future production.
Project Reference: 2447 Optimal irrigation Time
Botrytis Bunch Rot: Who, Where, When, and What to Use
Walt Mahaffee, Research Plant Pathologist USDA-ARS-HCRL
This project will aid Botrytis bunch rot management by improving our understanding how and where Botrytis bunch rot disease epidemics start and progress. First, it will identify when inoculum is available and infects fruit to optimize disease management practices. Second, it will determine the extent of fungicide resistance in Oregon vineyards to mitigate further spread of resistant populations. Together, the results from this project will allow Oregon grape growers to make better-informed integrative pest management decisions to control bunch rot.
Characterizing Willamette Valley soil moisture and grapevine response under drying seasonal conditions
Patty Skinkis, Professor and Viticulture Extension Specialist, Oregon State University.
Paul Schreiner, Research Plant Physiologist, USDA-ARS.
Willamette Valley vineyards experience late season water stress that may be limiting vine growth and production, depending on soil type and season. There is a need for producers to understand how to manage vineyard soil water, whether through irrigation or timely vineyard floor management. During this three-year project, we are monitoring soil moisture and Pinot noir grapevine growth, water stress, and fruit development and composition across three soil types. This work is underway in a commercial vineyard comprised of three soil types that are common to the region, including a sedimentary soil, volcanic soil, and marine sediment soil. To date, this study has generated continuous soil moisture data for two growing seasons, showing that we started both the 2020 and 2021 seasons with a full soil profile that did not start to decline until late June, or early July. This is an important finding, as many growers feared the dry 2021 spring would significantly impact vine growth, and we see that the vines are performing well. More work is in progress as of this reporting. Information will be useful to regional growers to understand soil moisture management.
Rootstock effects on mature Pinot noir growth and productivity under cool climate, dry-farmed conditions
Patty Skinkis, Professor and Viticulture Extension Specialist, Oregon State University.
The Oregon wine grape industry has experienced warmer, drier summers over the past decade. The first grafted vineyards were planted to three vigor reducing rootstocks (101-14, 3309 and Riparia Gloire). However, growers question the suitability of these rootstocks for the Willamette Valley given the drier conditions. There is great interest in understanding how rootstocks can be selected to help determine suitability for dry-farming and/or optimizing irrigation water in the region. Over three growing seasons, we are evaluating an established OSU rootstock trial (planted in 1997), with focus on Pinot noir growth response on 19 rootstocks and compared to own-rooted vines. We are monitoring phenological advancement, yield, basic fruit ripeness and more advanced measures of color and phenolics. To date, this project has shown the largest differences in rootstock is vine vegetative growth and yield, with no differences in bud break and bloom timing, but there are some differences in the start of ripening. Findings from this research will help growers make new vineyard plant material selections, by allowing them to consider the performance of varied rootstocks locally and under dry-farmed conditions.
