Updated 7/31/03

Lab tests needed to confirm sudden oak death

For more information, e-mail us or call (360) 586-8459.

Sudden oak death cannot be identified simply by looking at a plant because symptoms of the disease, such as leaf spots, shoot-tip dieback, or canker formations, resemble many other plant diseases. 

Sudden oak death is caused by a pathogen called Phytophthora ramorum. The disease can only be confirmed through laboratory testing that takes from two to three weeks. 

The steps needed to confirm sudden oak death are:

1. Samples of plant material are tested for traces of the pathogen.
2. If traces of Phytophthora ramorum are found, an attempt is made to grow the pathogen in a petri dish.
3. If step 2 produces a culture that resembles Phytophthora ramorum, a genetic test is run on the plant material to confirm the findings. 
4. At the same time as step 3, the culture is examined by a fungal expert to positively identify the pathogen.

 [Top of Page]