Phytophthora ramorum/Sudden Oak Death |
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Background
Phytophthora ramorum (Pr)
(also known as Sudden Oak Death, ramorum leaf blight and ramorum dieback)
Since the early 1990s, oaks and tanoaks have been dying in the coastal counties of California. Since then, other types of plants have been found to be infected or associated with this disease, referred to as Sudden Oak Death (SOD), ramorum leaf blight or ramorum dieback. Phytophthora ramorum is the pathogen that causes these diseases. Sudden Oak Death was first reported in 1995 in Mill Valley (Marin County) on tanoak. Since that time, the pathogen has been confirmed on various native hosts in fourteen coastal California counties (Marin, Santa Cruz, Sonoma, Napa, San Mateo, Monterey, Santa Clara, Mendocino, Solano, Alameda, Contra Costa, Humboldt, Lake, and San Francisco), and in Curry County, Oregon. Through ongoing surveys, APHIS-PPQ continues to define the extent of the pathogen’s distribution in the US and limit its artificial spread beyond infected areas through quarantine and a public education program.
Status: Regulations were published February 14, 2002, to control the artificial movement of sudden oak death from infested counties in California and an area under eradication in Oregon. Research being conducted by the Agriculture Research Service, US Forest Service, Universities and others is under way to better identify hosts, methods of detection, and effective treatments. Currently, more than 100 plants are regulated, five at the genus level (Camellia, Rhododendron, Viburnum, Pieris and Kalmia). There are no chemical treatments currently available to eliminate the disease in nursery stock.
On December 21, 2004, APHIS issued an emergency Federal Order that bolstered the Agency’s initial P. ramorum restrictions by regulating the interstate movement of nursery stock, from virtually all commercial nurseries in California, Oregon, and Washington. The Federal Order, which became effective on January 10, 2005, was enacted in response to detections of P. ramorum at commercial nurseries in California, Oregon, and Washington that are outside quarantined areas. This Federal Order was rescinded when it was replaced by an enhanced interim rule published in the Federal Register on 26 February 2006. A Final Rule, responding to and incorporating the comments officially received is pending.
For the latest list of regulated host and associated hosts, program updates, areas under quarantine, regulations and federal orders for P. ramorum, please visit the following links found on the P. ramorum homepage: