Sudden oak death (SOD), Phytophthora ramorum, is a federally
quarantined pathogen that has caused widespread dieback of tanoak and other oak
species in forested areas of 15 counties in California and parts of Curry County, Oregon. It has also been found infecting horticultural plants at nurseries in
California, Oregon, and Washington.
History of SOD in Oregon's nurseries
Sudden oak death (SOD) was first found in an Oregon nursery in 2003. It has been detected in limited nursery sites every year since then. When detected, the nursery must complete all requirements of the USDA confirmed nursery protocol.
Requirements include the following:
- Immediate quarantine of positive nursery
- Delimitation surveys to assess the extent of the infection
- Destruction of all infected plant material
- Trace survey inspections of all host material shipped and received by the nursery for previous 6 months
- Survey monitoring by inspection and sampling for the next 3 years
While more than 135 plants have been proven to be hosts of SOD, the following five are detected most often:
Oregon nurseries shipping plants out of state that are located within the quarantine area of Curry County or that have been found positive since March 31, 2011, are requried to meet requirements of the USDA Federal Order DA-2014-02.
Oregon nurseries approved to ship nursery stock out of state need to be listed on the Oregon Department of Agriculture website. Nurseries listed there are required to be inspected for presence of SOD annually. These nurseries are not required to use a USDA Phytophthora ramorum certification shield with their shipments.
Recipients of tree and shrub nursery stock imported into
Oregon are required to notify ODA.
APHIS list of regulated hosts and plants proven or associated with Phytophthora ramorum
California Oak Mortality Task Force
Oregon Public Broadcasting: Sudden Oak Death
Phytophthora ramorum a guide for Oregon nurseries
Phytophthora ramorum a guide for Oregon nurseries Document
Phytophthora ramorum: Sudden Oak Death
USDA Animal and Plant Health Inspection Service (APHIS)
Phytophthora ramorum: Sudden Oak Death regulations
Plant Plague: Sudden Oak Death
Bay area public broadcasting TV station KQED video story. Website
Safe procurement and production manual
P. ramorum—Safe procurement and production manual for nurseries. Document
Sudden Oak Death and Phytophthora ramorum: A summary of the literature