1. Gregory V. Jones Southern Oregon University Understanding what Water Deficits and Climate Variability Mean to Viticulture and Wine Production U.S. Drought Monitor Forum Portland, Oregon October 10-11, 2007

2. Talk Outline  Viticulture/Wine System  Grapes, Wine, and Climate  Water Requirements  Climate Variability  Overview and Conclusions

3. Viticulture/Wine System Overview Weather/Climate  Mild winters, low freeze/frost risk  Stable, cloud-free conditions during bloom  Warm and dry summers  Dry maturation period with moderate to high DTR Water  Low water need compared to other crops  Overall need or amount depends on location  If irrigated, mostly drip … very efficient  Greatest need in initial development (years 1-5)  Deficit irrigation practiced once mature  Some frost protection use Old World vs New World issues

4. Phenological Calendar with Weather/Climate/Water Issues FebMarAprJunAugSepNovJanMayJulOctDec Vegetative DevelopmentBerry DevelopmentDormant Stage Sap Bleeding VéraisonBud Break Bloom Maturation/ Harvest Leaf Fall Full Dormancy Berry Growth Cold hardiness limits Spring frost limit Adequate soil moisture recharge Combination of air and soil temperatures initiate bud break High solar potential Stable conditions Days 70-80°F No rain Irrigation starts in dry years/periods Adequate heat accumulation Days < 95°F, low heat stress Little to no rain Irrigation starts in wet years/periods If irrigating, deficit ET practiced Slow temperature decline best for latent buds Adequate chilling Stressed if soil moisture recharge is deficient

5. Australian Viticulture from text: “Ripening berries – a critical issue” by Dr. Bryan Coombe and Tony Clancy (Editor, Australian Viticulture), March/April 2001. Illustration by Jordan Koutroumanidis and provided by Don Neel Practical Winery and Vineyard Total Acidity Balance Zone Fruit character goes from vegetal, herbal, fruity, jammy to cooked. Quality Wine Production results from the balance of four ripeness clocks running simultaneously but at different rates:  Sugar accumulation  Acid respiration  Phenolic ripeness  Fruit character

6. Water/Irrigation needs in any particular location in any particular year are controlled by:  Spatial variations in climate  Year-to-year variations in weather  Soil type  Topography  Management (variety/clone, rootstock, spacing, cover-cropping, etc)

7. Water Deficit Issues:  Smaller canopy  Fewer and smaller clusters  Smaller grapes  Increased competition (ground cover, natives, between plants)  Soil salinity imbalances over the long term

8. Water Deficit Issues:  Non-irrigated vines … Quality ~ ↑ ↑ … Yield ~ ↓ ↓  Irrigated vines … Quality ~ ↑ ↑ … Yields maintained  However, if combined with high temperatures …  … increased plant stress/water demand and Quality ~ ↓ ↓ … Yield ~ ↓ ↓

9. Wine Production and Quality Metrics Yield/Production Balanced Composition Typical Varietal Flavors Vintage Ratings/Price Climate Metrics Growing Season Average Temperatures, Heat Accumulation Optimum Zone Consistent sugar levels, Ripe flavors, Generally balanced - Vintage variations driven by seasonal climate factors (frost, untimely rain, etc.) Too Warm Threshold Lower retention of acids, Overripe flavors, Unbalanced Too Cold Threshold Lower sugar levels, Unripe flavors, Unbalanced Varietal-Climate Thresholds Plasticity – Adaptation Management (short-term) Varietal (long-term)

10.  Climate influences the style of wine an area can produce  Each variety is generally grown in specific regions and narrow climatic zones for optimum quality and production Rhine Valley Burgundy Bordeaux Napa

11. 1950 Global Viticulture Zones National Center for Atmospheric Research’s Community Climate System Model (CCSM) A1B (mid-range scenario): 1.4° x 1.4° Lat/Lon Jones (2007) in preparation

12. 1999 Global Viticulture Zones Jones (2007) in preparation Isotherms shift poleward ~80-240 km (from 1950) Some expansion NH, mostly declines SH National Center for Atmospheric Research’s Community Climate System Model (CCSM) A1B (mid-range scenario): 1.4° x 1.4° Lat/Lon

13. Temporal & Spatial Variability in Growing Degree-Days 1996-2003 Jones, White, and Myers 2007 1988-19951980-1987 Napa Valley Willamette Valley Walla Valley

14. 1948-2004 15 Parameters 46 Climate Stations Aggregated to 11 Regions Puget Sound Columbia Valley, WA Columbia Valley, OR Willamette Valley Umpqua Valley Rogue Valley North Valley Foothills North Coast Central Coast Central Valley

15. Columbia Valley, WA Puget Sound Willamette Valley Umpqua Valley North Valley Central Valley North Coast Foothills Central Coast Columbia Valley, OR Rogue Valley Growing Season Growing Degree-Days 326 = Mean 94 = Stdev Year 200319991995199119871983197919751971196719631959195519511947 GrDD Anomalies (Apr-Oct, base 50°) 700 500 300 100 -100 -300 -500 -700 Rogue Valley 5 year moving average Linear trend

16. Columbia Valley, WA Puget Sound Willamette Valley Umpqua Valley North Valley Central Valley North Coast Foothills Central Coast Columbia Valley, OR Rogue Valley Median Date of Last Spring Frost (0°C) Descriptive Statistics Trend Parameters Region Mean Std. Dev. Max. Min. R 2 P-value a Decadal Trend Overall Trend Central Valley 2/25 16.7 3/30 1/14 0.13 *** -3.8 -20 North Valley 3/5 16.9 4/8 1/17 0.09 ** -3.3 -18 Central Coast 3/8 18.7 4/15 1/18 0.26 *** -6.3 -34 North Coast 3/9 22.4 4/22 1/13 0.46 *** -9.6 -52 Foothills 4/6 17.9 5/12 2/18 – Puget Sound 4/9 15.2 5/7 3/4 0.31 *** -5.0 -27 Umpqua Valley 4/20 17.7 5/17 2/28 0.23 *** -5.4 -29 Willamette Valley 4/25 13.6 5/21 3/21 0.17 *** -3.5 -19 Columbia Valley, WA 4/26 11.4 5/16 3/28 0.20 *** -3.1 -17 Rogue Valley 5/5 10.6 5/24 4/9 0.06 * -1.8 -8 Columbia Valley, OR 5/11 9.6 5/28 4/14 0.18 *** -2.5 -14 Year 2005200019951990198519801975197019651960195519501945 Anomaly in Days per Year 60 50 40 30 20 10 0 -10 -20 -30 -40 -50 -60 North Coast -24 = Mean 12 = Stdev 5 year moving average Linear trend

17. Napa Valley Cabernet Sauvignon Vintage Ratings (Wine Spectator)

18. Napa Valley Cabernet Sauvignon Release Price vs Vintage Ratings Rating effects on price are exponential, with a 10-point increase from 80 to 90 resulting in a 200% price increase and an increase from 85-95 resulting in a 350% price increase

19. PDO-ENSO Modulation Effects on West Coast U.S. Wine Regions and Wine Quality in Napa Valley

20. Impact of ENSO on Climate  In general, ENSO phase not important factor in variability of wine region climate – likely indirect through soil-water balance Impact of PDO on Climate  PDO was highly significant (P << 0.05) for most wine region temperature variables (11 of 15)  No significant differences in precipitation (opposite of ENSO)  Cold PDO linked to increased spring frost, low GrDDs Impact of PDO-ENSO Modulation on Climate  Greatest effects seen in wine region climates during neutral ENSO-cold PDO modulations – significant for Tavg, Tmin, GrDD, spring frost variables and total frost free days

21. Ratings and Teleconnections 1933-2002 ScenarioRatingSDnSig. El Niño88.74.819 P>0.4 La Niña85.39.217 Neutral84.48.930 Warm PDO88.26.136 P<0.01 Cold PDO83.19.430 El Niño-warm PDO87.75.211 P>0.3 El Niño-cold PDO90.14.18 La Niña-warm PDO88.86.86 P>0.2 La Niña-cold PDO83.410.111 Neutral ENSO-warm PDO88.36.719 P<<0.01 Neutral ENSO-cold PDO77.78.511 Of the 7 worst years (ratings <71), 6 are neutral ENSO-cold PDO

22. What about 1999-2002 and Beyond?  PDO has displayed more inter-annual variability since 1998  Ratings 5-year moving average appears headed down since 1997  1998, 2000, and 2002 all much lower than 5-year moving average Wine Spectator - Napa Valley Cabernet Sauvignon Vintage Ratings 60 65 70 75 80 85 90 95 100 1933 1937 1941 1945 194919531957196119651969 1973 1977 1981 1985 1989 1993 1997 2001 Year Vintage Rating ?? The 2005 and 2006 vintages have not been rated yet Climate structures during these years would point to highly rated vintages (>90) Early indications are for good wine quality, with 2005 a record for production

23. Jan-Jun Rainfall Anomaly (in) Salem 20052000199519901985198019751970196519601955195019451940193519301925192019151910 Year 15 10 5 0 -5 -10 Roseburg MedfordPendleton 1985 2001 1977 1985 2001 1994 1985 2001 1973 1992 1964 1996 1999 1983 1998 1996 1983 1956 1998 1996 2000 1995 1978 Oregon Regional Irrigation Climatology for Winegrapes

24. Simulated Soil Moisture and Cumulative Irrigation – Rogue Valley 1999 = dry/warm; 2000 = typical; 2005 = wet/cool Statewide Annual Variation in Irrigation Needs (1989-2006) Range of Replenishment Needed - 2.5 to 12.8 inches “Dry/warm” years 13-71% increase, 5-24 days earlier “Wet/cool” years 14-30% decrease, 11-22 days later Medford Agrimet, Ruch Gravelly Silt Loam

25.  The viticulture/wine production system is a unique specialty crop with strong value added components driven by a wide range of varieties.  Wine production is a climatically sensitive endeavor, with narrow zones providing the most optimum production and quality characteristics, which therefore puts the industry at great risk from both short term climate variations and long term change.  Desirably low summer/fall rainfall, low water requirements compared to other crops, and efficient irrigation methods make wine production more suited to regions prone to drought.  Some controlled water deficit is good for quality, however long term drought can bring about smaller yields and soil salinity imbalances. Overview and Conclusions

27. 0 10 20 30 40 50 60 70 192719421957197219872002 Winter (Oct-Mar) Count #of Days<20°F #of Days<5°F Moving Average Eastern Oregon and Washington Extreme Freeze Frequencies

28. Eastern Oregon and Washington Extreme Minimum Temperatures