Skip to main content
ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #161983
Title: WATER MANAGEMENT TO OPTIMIZE CANOPY, YIELD, AND QUALITY OF CABERNET SAUVIGNON

Author
item Shellie, Krista

Submitted to: Northwest Center for Small Fruit Research Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/1/2003
Publication Date: 12/4/2003
Citation: Shellie, K. 2003. Water management to optimize canopy, yield, and quality of Merlot. Northwest Center for Small Fruit Research Proceedings. 80-81.

Interpretive Summary:

Technical Abstract: Four irrigation regimes (full vine evapotranspiration (FVET), 70% FVET, 35-70% FVET, and 35% FVET) were evaluated in a randomized block design with four plot replications (4 rows of 14 vines/plot) in a field trial, established spring 2002, within a 12 hectare block of own-rooted, four year old, 'Merlot' grapes at Skyline Vineyard in Nampa, ID. Vines were pruned to a similar bud number on a double trunked, unilateral cordon with vertical shoot positioning and north south rows. Soil moisture and leaf water potential were monitored weekly and irrigation was based on reference evapotranspiration, growing degree-day, and a Washington derived wine grape crop coefficient. Irrigation treatments were initiated after flowering when leaf water potential reached -1.3 MPa and a uniform canopy was established. East and west exposed clusters were sampled at harvest and analyzed for berry weight, skin weight, component sugars and acids, monomeric anthocyanins, total phenols, and flavonols. Wine was produced from 150 lbs of grapes from each field plot, and evaluated for color intensity, total phenols, flavonols, and subjective quality. Results from year one suggest that irrigation significantly affected lateral shoot growth, trunk growth, berry weight, shatter, yield, and ripening rate. The 35% FVET treatment had the lowest amount of tartaric acid, and produced wine with highest color intensity. A significant interaction was observed between canopy cluster location and irrigation regime. East exposed clusters receiving 35-70% FVET and FVET accumulated more glucose and fructose, than east exposed clusters receiving 35% or 70% FVET. In east exposed clusters, malic acid content decreased as vine water stress increased. The glucose, fructose, and malic acid content of west exposed clusters were lower than east exposed clusters, regardless of irrigation. Preliminary results suggest that targeted water stress through irrigation management and cluster canopy location influence grape derived determinants of wine quality.