P. ramorum in Washington nurseries

A Snohomish County wholesale/production nursery was confirmed P. ramorum positive on May 27^th during an Annual Compliance Inspection. The nursery was previously positive in 2008 and 2010. The Confirmed Nursery Protocol, including delimitation of all stock and collection of trace-forward and trace-back information is underway. Though they are under compliance agreement as an interstate host shipper, the nursery has not made an interstate shipment in the past 12 months. Positive species include Mahonia aquifolium, Gaultheria shallon and Arctostaphylos uva-ursi.

From the June COMTF Report

P. ramorum in Washington waterways

Washington had two repeat P. ramorum-positive waterway detections in May. One of the sites has been positive since 2009 and the other since 2010. Each positive stream feeds into the Sammamish River. Both sites have had positive samples recovered upstream from the confluence of the water course and the Sammamish (baiting by WSDA and WA DNR); the inoculum source for each is unknown.

from the June COMTF report

Oregon nurseries stave off SOD pathogen despite wet weather

Detections down despite cooler, wetter spring weather

By MATEUSZ PERKOWSKI

Capital Press

Damp and cool conditions are typically conducive to sudden oak death, but Oregon nurseries haven't seen a surge in the fungal-like pathogen despite the dreary weather this spring.

The disease has been detected at three Oregon nurseries so far in 2011, which is the same number as at this point last year, according to the Oregon Department of Agriculture.

During the entire 2010 season, the ODA's testing program found phytophthora ramorum, which causes the disease, at nine nurseries. That's roughly half as many detections as during the peak years of 2004 and 2005.

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WSU monitoring on Clarks Creek

A link to a page on WSU stream monitoring for Phytophthora on Clarks Creek, Puyallup, WA:

http://www.cityofpuyallup.org/services/development-services/puyallups-stormwater-management-program/clarks-creek-initiative/current-restoration-efforts/

Department gives update on Phytophthora ramorum Monitoring

The Department of Agriculture, Food and the Marine is continuing to survey forests and control outbreaks of the EU regulated plant disease Phytophthora ramorum, a fungus like organism that can damage and kill infected trees and plants. Under EU requirements, annual forest surveys for Phytophthora ramorum have been ongoing since 2003. Until last year, there had been no findings on tree species and P. ramorum had only been detected in forest areas on wild invasive rhododendron shrubs. Following the initial findings in Japanese larch in Ireland in July 2010, an extensive national aerial and ground survey was conducted. These forest surveys have now confirmed the disease in Japanese larch at eleven forest locations in five counties.

Japanese larch appears to be particularly susceptible to the disease, affecting all age classes and locally causing significant dieback and deaths. Noble fir, beech and Spanish chestnut growing in close proximity to the infected Japanese larch have also been found to be infected at a number of the sites and it is likely that the Japanese larch is the source of the infection. The infected trees are being removed to prevent the disease spreading.

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Killer disease found in two new species of Irish tree

Two thirds of Northern Ireland's forests are under threat from a killer tree disease.

The fungal disease P. ramorum (often called Sudden Oak Death) has already infected tens of thousands of Japanese larch trees.

This has led to the felling of over 200 hectares across nine woodlands.

The disease may have jumped species and has infected a Sitka spruce in the Republic of Ireland and several beech trees in County Down, in the north.

If the disease spreads to other Sitka trees it could be a disaster for the Northern Ireland Forestry Service. The species makes up two thirds of all government-owned forests in Northern Ireland.

The disease was already known to be able to infect beech trees. It has also been confirmed that the infection has been found in European larch in England.

BBC News

Read more here

Sudden Oak Death is not going away

A good description of SOD in California, its hosts, and behavior:

Earlier this month I had the pleasure of visiting the campus at UC Berkeley to attend a training session on Sudden Oak Death (SOD), the disease that has killed many thousands of trees in California and other parts of the world. Losses include many coast live oaks here in Napa County.

To see for yourself, take a short drive up Partrick Road, where the woods are dense. You are likely to spot a number of dead coast live oak trees in this area where SOD was confirmed fairly early in the onset of the epidemic.

The UC Berkeley Forest Pathology and Mycology Lab, which originally identified the disease when it was new to California, continues to refine our understanding of it while it also leads community volunteer efforts to map and mange the disease. The lab sponsors ongoing training for those who are interested in the problem or directly involved in its management.

The March 9 training session, held in the shadow of a large coast live oak by the Tolman Hall portico, was led by lead researcher Matteo Garbelotto, the associate extension specialist and associate adjunct professor who heads the lab research. The lab also sponsors a unique community involvement effort known as “SOD Blitz” days, one of which will be held in Napa on June 4.

Prof. Garbelotto summarized the history of the disease in California from its beginnings to the current state of the research on its biology and management.

Read more here - Trees & People by Bill Pramuk, Napa Valley Register, Saturday, March 26, 2011