1. Agro-thermal heat treatment of
Grapevines in the Okanagan
Chad Douglas - Viticulturist, Quails’ Gate Estate Winery

2. Agro-thermal heat treatment of
Grapevines in the Okanagan
 What are the challenges/concerns for winegrape growers in a changing
climate?
 What are some approaches to mitigate these concerns?
 Agro-thermal Systems – how does heat treatment (thermaculture) fit into this?
 Quails’ Gate Estate Winery 2019
 FAIP Project

3. Challenges/issues for vineyards in a
changing climate?
 Concern: Loss of varietal character – what does this mean?
 Once vineyard is established limited options to mitigate climate
 Warming and more extreme climate trends
 Plant vineyards to cooler sites;
 higher latitude, higher altitude, northern aspects
= greater climatic risk ie. Frost, winter damage

4. Challenges/issues for vineyards in a
changing climate?
 Concern: Yield and ripening consistencies
 Grapevines very sensitive to temperature during key phenological stages
 Flowering and fruit-set;
 poor or uneven set
 Veraison - Ripening/maturation of grapes
 Low or high brix and sugar, unbalanced fruit and wine

5. Challenges/issues for vineyards in a
changing climate?
 Concern: Increased Disease pressure
 Specifically powdery mildew and botrytis
 Increased rain events, higher humidity = increased disease pressure
 Rotate chemistries, practice better IPM
 Spray more
 Rely on Chemical companies to formulate new products

6. Challenges/issues for vineyards in a
changing climate?
 Concern: Sustainability issues
 Fungicide and pesticide resistance
 FRAC: Group 3, 11 chemistries in-particular.
 Pesticide applicator health and safety
 Cost of fungicides, cost of increased number of sprays
 Residual fungicides/pesticides in wine

7. Agro-thermal Systems – how does heat
treatment fit into this?
 How does it work;
 Propane operated, hydraulic fan heater, generating 350+ degrees F hot air
 Video https://www.youtube.com/watch?v=cRDt7jlN930
 Instantaneous Heat Shock – activates plants self-defense mechanism
 Claims state; heat results in:
 Increase flower bud pollination; increase number of berries set = increase yield
 Impact and kill fungal and bacterial spores
 Increase plant phenol and antioxidant properties
 Costs; propane approx. $8/ac + tractor driver @ 3.5mph
 My experience in Oregon
 2014-15 Growing seasons; Yield and botrytis trials

8. Quails’ Gate Estate Trials 2019
- 2 year trial in collaboration with UBCO
 1. Botrytis cinerea; Chardonnay 3 treatments
 Conventional program (1 botryticide)
 Heat treatment only
 Control – no botryticide, no heat
 2. Vine metrics; Merlot treated vs non-treated
 Yield, brix, pH, TA, others…
 1st year results: No significant difference
 3. Crown-gall – Agro-bacterium Vitis;
 In-conjuction with other trail treatments in block

9. Quails’ Gate Estate Winery 2019
- other applications.
 1. Ripening – increase brix
 Cabernet Sauvignon in Northern Okanagan
 3 applications after veraison
 Crop-load: 3.6 T/a Brix: 25.4 (no-control)
 2. Powdery Mildew
 New lease - organic vineyard
 Large population of over-wintering spores – black canes
 6 x Sulphur + 5 x Heat = ZERO Mildew and Botrytis
 3. Wine phenolics
 Merlot block; treated vs non-treated
 Juice panel to assess; tannin, anthocyanin
 Formal tasting and evaluation to come

10. Agro-thermal heat treatment of
Grapevines in the Okanagan - Summary
 Climate trends are warming with more extremes
 Known challenges for winegrape farmers
 Strategies to mitigate these challenges
 Is Agro-thermal heat treatment one of them, another tool to add?
 Technology claims need to be validated… we hope to do that.
 Thank-you
 BC Agricultural Climate Adaptation Organization
 Quails’ Gate Estate Winery
 UBCO; Louise Nelson, Tanja Voegel and their team