Title: Use of Direct Root-Zone Micro-Irrigation to Conserve Water and Enhance Grape Quality

Project Duration: 2017-2019

Principal Investigator(s): Pete W. Jacoby
Organization: Washington State University
Address: P.O. Box 646420, Pullman, WA 99164-6420
Telephone: 509-335-3495
Email: jacoby@wsu.edu

Cooperator Name: Scott Williams
Organization: Kiona Winery
Description of Participation: Provided vines and management

Cooperator Name: Rick Hamman
Organization: Hogue Ranches
Description of Participation: Provided vines and management

Project Summary:

What is the current issue and why did it need to be researched?

  • Improvement of crop water use efficiency was needed to ensure sufficient water availability for continued growth of the WA grape based industries. A new method of delivering subsurface drip irrigation was hypothesized to be a means of conserving water while sustaining grape yields and quality. Industry funding and grower participation were needed to conduct a proof of concept trial in commercial production vineyards.

What were the basic methods and approaches used to collect data that will be used to inform the target audience?

  • Treatments included 3 rates of water applied at three depths of water under continuous and pulsed delivery schedules during 2016. In 2017, rates of direct root-zone (DRZ) delivery were adjusted to 80, 60, and 40 percent of surface drip applied at a depth of 2-feet below soil surface. DRZ was compared with equal rates of water applied at full commercial rate and also 80, 60, and 40 percent of full commercial rate delivered by surface drip. Grapes from plots were harvested in fall, and total vine grape yields were weighed. Cluster samples from each treatment plot were submitted for a full phenolic panel analysis by ETS in Walla Walla, WA. Statistical analyses of data were performed in Pullman, WA.

What ultimate goals did the project hope to achieve?

  • The overarch goal of this project was to determine the potential of DRZ micro-irrigation to conserve water. Secondary goals were to: 1) determine the impacts on grape yields and quality from applying less than the commercial surface drip rate; and, 2) determine the extent of water savings by using DRZ rather than surface drip for the portion of the growing season from fruit set until harvest.

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Irrigation // Sustainability //