By BRYAN BERENGUER
All of us are experiencing climate change, be it extreme heat or cold events, unusually heavy rainfall or strong winds. However, agriculture is affected particularly hard as crops, and the surrounding ecosystem in which they are produced, are completely dependent on the weather.
Furthermore, perennial crops such as wine grapes have a life cycle of more than 25 years and are also heavily influenced by long term climate patterns.
Air temperature is the key driver of grapevine growth and a significant environmental factor impacting yield and quality for a grapevine growing region. For example, the Willamette Valley has become world renowned for its production of high-quality Pinot Noir, a premium wine grape that requires very specific and narrow growing season temperatures (an average of 55-59 degrees Fahrenheit).
These temperatures, combined with dry summers, is what makes the Willamette Valley perfect for growing Pinot Noir.
Climate change is affecting the Oregon wine grape industry in both the long and short term.
One is “Global Warming”, or the steady increase in average temperatures over the foreseeable future. This pushes grapevines to grow faster and, more importantly, flower earlier, leading to an increasingly earlier harvest.
In fact, 2023 was one of the shortest growing seasons on record in Oregon.
Anthocyanin (the red color in red wine), proanthocyanin (tannins) and Flavanol (flavors) production are at their best when grape ripening occurs during periods of warm days and cool nights. Hence, the fall (late September, early October) is the optimal time for wine grape ripening.
Harvesting earlier in the year when days are hot and nights are mild can be detrimental to wine grape quality. Pinot Noir ripening is predicted to advance by 2.9 days a decade from the 1960s through the 2080s, according to recent climate forecasting research focused on Pinot Noir in Oregon.
An earlier harvest is only one detriment from global warming, another is a potential earlier bud break date (or the start of grapevine growth from winter dormancy) which puts vineyards at a significantly higher risk of damage by spring frosts.
The erratic and extreme weather events that come with climate change are a current and future challenge.
The wildfires of 2020, the heat dome of 2021 and the frost of 2022 are just a few recent incidents that have affected vineyards in this decade. These events are extremely difficult to plan for and react to, as current strategies for mitigation vary greatly and have low percentage of success.
The dry periods occurring in the summer have also been lengthening, making it challenging for vineyards on shallow soils without irrigation.
However, the wine grape industry is adapting. Recent research from OSU is making grape growers rethink their rootstock choices when planting new vineyards, opting for more drought tolerant options.
Vineyards are being planted at higher elevations that were previously considered too cold, but are not in the optimal range for Pinot Noir. Also, new wine grape cultivars that require slightly warmer temperatures are being planted, such as Gamay Noir.
(Bryan Berenguer is with Chemeketa Community College)
Contact Keizertimes Staff:
[email protected] or 503-390-1051
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