GOLD BEACH – State forestry officials said that treatment of a 20-acre core area of an infestation of Sudden Oak Death (SOD) discovered recently at Cape Sebastian State Park was almost complete.

“The core area will be done tomorrow (Friday),” Sudden Oak Death Forester Stacy K. Savona said at a meeting in Gold Beach Thursday night. “It’s cut and burned.”

“We are getting excellent cooperation from State Parks, fair from ODOT,” Alan Kanaskie, forest pathologist with the Oregon Department of Forestry, said at the meeting.

 Officials said there were 25 infected tanoak trees in that core area, located near Meyer Creek Road where Sebastian Lane cuts off that road.

Kanaskie said foresters had been cutting and burning infected trees for 10 years.

“There is some good evidence we have slowed it down, but we haven’t stopped it,” he said.

State foresters have discovered trees infected with SOD at the site more than six miles north of a quarantine boundary established to stop the spread of the infection.

“That’s the biggest jump we’ve had,” Kanaskie said. 

He said part of the spread is caused by wet weather in winter.

“If we can get some of the spores cut and burned by Christmas, there’s a good chance of limiting spread,” he said.

Kanaskie said that more than $11 million has been spent to slow the spread since it was first discovered in Curry County, but the number of infected sites is going up and “funding is going in other directions.”

He said the state forest service will no longer cut infected trees well inside the quarantine area.

“We’re going to have to have treatment perimeters because of the funding we have,” he said

He noted some property owners are using fungicide to treat infected trees on their property.

“Fungicide will not control the spread, but it might prolong life of the tree,” Kanaskie said.

Efforts to eradicate the disease from the south Oregon coast have continued since it was first found in 2001. Those efforts have included enforcing a quarantine area in the general vicinity of Brookings, and continuing a program of early detection and removal of affected or susceptible trees through cutting and burning. 

Officials said the Cape Sebastian State Park discovery of Phytophthora ramorum – the fungus that causes Sudden Oak Death – is evidence that the disease has spread in Curry County outside the previously established quarantine area.

Kanaskie said in September that two tanoak trees infected with the pathogen Phytophthora ramorum were noted by the department’s insect and disease specialists through aerial detection in Cape Sebastian park, just north of Pistol River.

Kanaskie said follow-up survey work on the ground confirmed the diagnosis. Other tanoak trees in the immediate vicinity also showed browning of the lower tree crown, which can be an early symptom of Sudden Oak Death.

The Cape Sebastian State Park infection site and a three mile buffer zone are now included in the Sudden Oak Death quarantine area. Plant species susceptible to P. ramorum and soil associated with the infected trees cannot be moved out of the area, unless heat treated to required specifications.  

SOD can kill highly susceptible tree species such as tanoak, coast live oak, and California black oak by causing lesions on the main stem. Tanoak is by far the most susceptible species in Oregon, and the disease seriously threatens the future of this species. 

The pathogen also causes leaf blight or dieback on many other host plants including rhododendron, evergreen huckleberry and Oregon myrtle. Oregon’s Douglas fir also can be infected by the pathogen but it is not seriously damaged. Early detection of SOD is achieved through a combination of aerial survey, follow-up ground visits and monitoring the presence of the SOD pathogen in streams. These efforts are critical to ongoing attempts to slow spread of the pathogen in Oregon.