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): Jared M. LeBoldus; Kelsey L. Søndreli
    Date: 2020
    Source: Proceedings of the seventh sudden oak death science and management symposium: healthy plants in a world with <em>Phytophthora</em>. Gen. Tech. Rep. PSW-GTR-268
    Publication Series: General Technical Report (GTR)
    Station: Pacific Southwest Research Station
    PDF: Download Publication  (355.0 KB)

    Description

    Phytophthora ramorum, cause of Sudden Oak Death (SOD), is an invasive pathogen that infects over 100 species of plants and has been introduced multiple times into the coastal forests of southern Oregon and northern California. In southwestern Oregon forests, tanoak (Notholithocarpus densiflorus) is the most susceptible species developing lethal stem cankers and sporulating from infected leaves and branches. The NA1 lineage was first reported in Oregon in the early 2000s and in 2015 the EU1 lineage was discovered infecting tanoak in the South Fork Pistol River drainage in Curry Co., Oregon. Using an approach developed by Garbelotto and others (2017) sporulation of each lineage was compared at six sites (3 NA1; 3 EU1). Sporulation, temperature, and relative humidity were quantified for 5, 2-week intervals in winter 2017/2018 and 2018/2019. In addition, infection frequency of tanoak, Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla), western larch (Larix occidentalis), and sitka spruce (Picea sitchensis) seedlings at the sites was also compared. Preliminary analysis indicates greater sporulation at EU1 sites compared to NA1; however, this did not correspond to increased infection of tanoak seedlings at EU1 versus NA1 sites. In contrast, there were differences in the infection frequency of Douglas-fir (EU1 = 37%; NA1 = 10%), western hemlock (EU1 = 10%; NA1 = 0%); sitka spruce (EU1 = 55%; NA1 = 0%); and larch (EU1 = 90%; NA1 = 13%). Differences in the infection rate of conifer seedlings at EU1 compared to NA1 sites and the implication for the management of SOD will be discussed.

    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

    LeBoldus, Jared M.; Søndreli, Kelsey L. 2020. Comparative epidemiology of EU1 and NA1 lineages of Phytophthora ramorum in southwestern Oregon tanoak forests. In: Frankel, Susan J.; Alexander, Janice M., tech. cords. Proceedings of the seventh sudden oak death science and management symposium: healthy plants in a world with Phytophthora. Gen. Tech. Rep. PSW-GTR-268. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 4-5.

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/60472