Skip to main content
ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #303471
Title: Deficit irrigation strategies and wine grape cold hardiness

Author
item Shellie, Krista

Submitted to: Hortscience Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2014
Publication Date: 7/28/2014
Citation: Shellie, K. 2014. Deficit irrigation strategies and wine grape cold hardiness. Hortscience Proceedings Supplement. 49(9):S310-S311.

Interpretive Summary:

Technical Abstract: Winter survival of winegrapes grown at northern latitudes depends upon the ability of dormant tissue to withstand low temperature exposure and acclimate to winter temperature fluctuations. Deficit irrigation is used extensively in arid wine grape production regions to manage growth for improved grape quality, yet the influence of different deficit irrigation strategies on the resilience of grape tissue to winter injury has received little research attention. The cold hardiness of field-grown vines of the cultivar Merlot was evaluated after a minimum of six sequential growing seasons of sustained (SDI) or regulated (RDI) deficit irrigation. Replicated trial plots were irrigated with a fractional amount of their estimated crop evapotranspiration (ETc) (90, 70, or 35%) from fruit set to harvest (SDI) or with 35% ETc pre-veraison increased to 70% ETc from veraison to harvest (RDI). Cold hardiness was evaluated by ratings of visible spring injury, bud-forcing bioassays and Differential Thermal Analysis (DTA). Vines under SDI at 70 or 90% ETc or RDI had significantly less visible spring injury than vines under SDI at 35% ETc. The xylem tissue of dormant vines irrigated with SDI at 35% ETc had low temperature exotherms at a warmer temperature than vines under RDI or under SDI at 90% ETc. Single node, dormant cane sections from vines under SDI at 35% ETc de-acclimated significantly faster than vines under RDI or SDI at 90% ETc. Results from this research indicate that irrigation practices during the growing season, particularly vine water deficit severity and phenological timing of deficit severity, influence subsequent cold hardiness of vine tissue. The alleviation of water deficit severity between veraison and harvest beneficially influenced cold hardiness. Development of irrigation strategies to enhance grapevine cold hardiness requires an understanding of the underlying mechanisms by which water status influences cold hardiness in grapevine. Results from this research demonstrate that this topic warrants further investigation.