Canadian Forest Service Publications

An overview of the Sudden Oak Death (SOD) disease caused by Phytophthora ramorum: Research Results and Challenges for the Pacific Northwest of North America. 2012. Elliott, M.; Shamoun, S.F.; Chastagner, G. Pages 30-45 in S.K. Lee, I.K. Park, S.S. Seo, S.H. Lee, W.I. Choi, and J.H. Park, editors. International Symposium on Oak Forest Preservation. Understanding and Managing Major Insect Pests and Diseases of Oaks, August 27-29, 2012, Seoul, Korea. Korea Forest Research Institute (KFRI), Seoul, Korea.

Year: 2012

Issued by: Pacific Forestry Centre

Catalog ID: 34143

Language: English

Availability: PDF (download)

Mark record


Sudden Oak Death (SOD), caused by the fungus-like pathogen Phytophthora ramorum, is a recently introduced plant disease killing oak and tanoak trees and causing foliar blight and shoot dieback on more than 100 plant species in North America and Europe. There are 14 California counties known to have Sudden Oak Death in the wild. In the Pacific Northwest (PNW) P. ramorum has been found in and near nurseries and eradicated. In Curry county, OR, P. ramorum is present in forests, where eradication and containment efforts have slowed its spread. It has also been found in several European countries in nurseries, gardens, and forested areas. Phytophthora ramorum has not been detected in the Southern hemisphere or in Asia. The disease is moved to new areas through the nursery trade and there is concern for spread to forests in the eastern US, where there are susceptible oak and understory species. It is important to prevent movement of P. ramorum in nursery stock. Research on biology and management of P. ramorum as well as a study of the potential risk to PNW forests is described. These research projects include a study of chemical fungicides on different life stages of the pathogen, testing of biocontrol products for use in controlling P. ramorum on foliage, examination of variability among isolates of P. ramorum, and screening of broadleaved trees and shrubs common in the PNW for susceptibility and sporulation potential of P. ramorum on foliage in order to evaluate the risk that this pathogen will become established in PNW forests.