Module 2: Disease Management
Module 1: Biology, symptoms, and Diagnosis
Welcome Module 3: Phytophthora ramorum Conclusion Take the Exam Further Information

Disease Cycle



Practice Questions








Introduction (continued)

Bleeding canker on tanoak.

Photo by M. McWilliams.


Bleeding canker on coast live oak.

Photo by S. Tjosvold.

Symptoms and ID on Oak and Tanoak

Phytophthora ramorum causes two types of diseases, depending on the host. On members of the oak family (Fagaceae), it causes stem cankers that kill the host; hence the name “sudden oak death.”  These cankers often show the characteristic “bleeding” symptom, such as in the photos below and at right.

Bleeding on tanoak caused by Phytophthora ramorum.

Photo by J. Parke.

It is important to note that not all oak species are affected by Phytophthora ramorum. Oregon white oak (Quercus garryanna) has not become infected by this pathogen.

<< Previous Next >>

Oregon State University Extended Campus
4943 The Valley Library, Corvallis, OR 97331-4504
800-667-1465 | 541-737-9204
Contact us with your comments and questions
Copyright 2008 Oregon State University