Abstract:
Sudden Oak Death is the common name for a disease caused by Phytophthora ramorum, a previously unknown and recently introduced non-native pathogen.
• Phytophthora ramorum has killed hundreds of thousands of oak and tanoak trees in 14 coastal counties in California and hundreds of tanoak trees in Curry County, Oregon.
• The pathogen has a wide host range including Douglas-fir, grand fir, coast redwood, and many other tree and shrub species common in Oregon and Washington forests. Tree mortality, branch and shoot dieback, and leaf spots result from infection depending on host species and location.
• Phytophthora ramorum spreads aerially by wind and winddriven rain and moves within forest canopies from tree tops to stems and shrubs and from understory plants to overstory trees. The pathogen survives in infested plant material, litter, soil, and water. It is moved long distances in nursery stock.
• State and federal personnel regularly survey forests and nurseries in the Pacific Northwest to detect the disease.
• Quarantine regulations, which include inspection and sanitation,
are in place and are revised as necessary.
• In Oregon and Washington, when infected plants are discovered,
they and neighboring host plants are destroyed.
• YOUR HELP is needed to protect Oregon and Washington
from further damage from Phytophthora ramorum!
