Sudden Oak Death (Phytophthora ramorum)

Agricultural Disaster Preparedness and Recovery May 29, 2013 Print Friendly and PDF

Sudden oak death, Phytophthora ramorum, is a funguslike disease that causes leaf spots, cankers, and dieback in more than 12 families of plants. Also known as ramorum leaf blight or ramorum dieback, the disease has been found primarily in California and Oregon. It is of concern to land managers in the eastern United States because at least two eastern oak species, northern pin oak (Quercus palustris) and northern red oak (Quercus rubra), are highly susceptible to the disease.


Signs of the Disease

Be aware of the signs of sudden oak death. Some species, including coast live oak, black oak, Shreve oak, and tanoak, sustain lethal trunk infections, while other plants get less serious leaf and twig infections.

Plants with leaf infections play a key role in the spread of sudden oak death because the disease is moved through the air by windblown rain.

Anyone who suspects that the disease is present in a new location should contact the local Extension office for reporting information.


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This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.