Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Ken Shackel; Rob Gross
    Date: 2002
    Source: In: Standiford, Richard B., et al, tech. editor. Proceedings of the Fifth Symposium on Oak Woodlands: Oaks in California's Challenging Landscape. Gen. Tech. Rep. PSW-GTR-184, Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture: 397-402
    Publication Series: General Technical Report (GTR)
    Station: Pacific Southwest Research Station
    PDF: View PDF  (230 KB)

    Description

    In a number of deciduous tree crops a reliable pressure chamber measurement of water stress (midday stem water potential or SWP) has been recently developed and found to be closely related to both irrigation regime and tree physiological responses to stress. A standard pressure chamber is used for the measurement of SWP, but prior to sampling, the leaf is enclosed in a reflective plastic bag and allowed to equilibrate with the water potential in the stem at the point of leaf attachment. In this study, measurements were made on valley oak trees under a variety of landscape conditions in Napa and Sonoma Counties, CA. Measurements on leaves that were only allowed to equilibrate for relatively short times (10 to 15 minutes) were compared to the SWP as measured by adjacent leaves that were allowed to equilibrate for over 1h. As found in other tree species, a 10- to 15-minute covering period appears sufficient in valley oaks for interior canopy shaded leaves to equilibrate with SWP. Using SWP in valley oaks that were nearby construction sites or agricultural land preparation, we confirmed that water stress was associated with root damage caused by these activities. SWP was also sensitive enough to follow the development of and the recovery from water stress over a number of irrigation cycles in an individual tree. We believe that SWP will be a valuable tool to determine the water needs of landscape valley oaks, particularly those with damaged root systems, while avoiding the potential for root disease development due to over-irrigation.

    Publication Notes

    • You may send email to psw_communications@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Shackel, Ken; Gross, Rob. 2002. Using midday stem water potential to assess irrigation needs of landscape valley oaks. In: Standiford, Richard B., et al, tech. editor. Proceedings of the Fifth Symposium on Oak Woodlands: Oaks in California''s Challenging Landscape. Gen. Tech. Rep. PSW-GTR-184, Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture: 397-402

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/26140