Video - using steam to treat soils infested with P. ramorum

On youtube - an interview with Rick Bostock, UC Davis, on steam treatment of soils

http://www.youtube.com/watch?v=MQYrB4PNK4Q

New Article

The August 2012 IUFRO Pathology Newsletter featured the article “Communicating Forest Pathology Issues to a Broad Audience”.  The story discusses how forest diseases caused by Phytophthoras have become increasingly visible to the general public as trees within recreational areas have succumbed to disease.  Sudden Oak Death (California), kauri dieback (New Zealand), and P. cinnamomi (Australia) are cited as three examples of devastating disease involving Phytophthoras that have had good coordination among scientists and different levels of government, resulting in effective research programs and communications strategies being put in place to help understand each problem and raise public awareness in an attempt to reduce pathogen spread.

From August COMTF newsletter.

Read the rest of the newsletter to learn more about forest diseases worldwide.

Oregon nursery updates

To date this year, the Oregon Department of Agriculture (ODA) confirmed 11 P. ramorum-positive nurseries in Clackamas, Curry, Lane, Lincoln, Marion, Multnomah, Polk, Tillamook, and Washington Counties.  Infected plants have included Camellia japonica; C. japonica ‘Grand Prix’ and ‘Mrs. Tingley;’ Hamamelis virginiana; Kalmia latifolia; Pieris sp.; P. japonica; Rhododendron cultivars ‘Baden Baden,’ ‘Bessie Howell,’ ‘Black Sport,’ ‘Holden,’ and ‘Maximum Roseum;’ Rhododendron sp.; Viburnum sp.; V. davidii; and V. tinus.  The Confirmed Nursery Protocol is underway at all 11 nurseries.

The positive plants found in the Curry County nursery (now closed for business) were infected with the EU1 lineage.  No infected plants were found at the nursery during inspection last year; however, 13 infected plants were found this year.  This is the first report of the EU1 lineage in Curry County.  ODA has implemented a voluntary recall for all potentially infected plants sold from the nursery.  Follow-up inspections have been negative for the pathogen; ongoing monitoring is still underway.

P. ramorum was also detected at a private residence in Lane County (Oregon) based on trace-forward information received from USDA APHIS.  The pathogen was detected infecting Gaultheria shallon and G. procumbens plants that had been imported from Washington and were still in their containers.  The USDA Confirmed Residential Protocol has been implemented.  For more information, contact Nancy Osterbauer at nosterbauer@oda.state.or.us.

From August COMTF newsletter.

New P. ramorum area in Curry County

A new Phytophthora ramorum outbreak has been identified on the Rogue River-Siskiyou National Forest 10 miles east of Brookings, OR.  The site is ½ mile east of the current quarantine boundary; therefore, an emergency quarantine was put into effect, bringing Oregon’s Sudden Oak Death (SOD) quarantine area to 229 square miles.  The outbreak was found when two dead tanoaks were identified in the Wheeler Creek drainage near Chimney Camp during April aerial surveys conducted by the Oregon Department of Forestry and the USDA Forest Service.  Subsequent ground surveys in the area identified 16 trees that are culture-positive for P. ramorum.  A hiking trail close to the site has been closed to the public since early June while officials work to eradicate the infestation.  Approximately 50 acres are being treated.

From August COMTF newsletter.

Washington nursery update

Washington has had 10 confirmed positive nurseries to date in 2012, the most in a single year since 2006. Counties with detections include King, Pierce, Thurston, Lewis, Clark, Clallam, and Skagit. Eight of the nurseries are repeat positives and six are certified interstate host shippers, three of which have shipped host and associated host plant material in the past six months. Positive plants have included Rhododendron, Viburnum, Camellia, Magnolia, two Pieris, and one Gaultheria. With most of the positive nurseries in Washington catering to the landscape trade, and the housing industry slow, at least four of the 10 sites have had some of the currently positive plants in the nursery yard for over a year. It is unknown how long they have been infected on site.

From the July 2012 COMTF newsletter

Stream monitoring update

A stream in western Washington and one in northern Georgia have been found P. ramorum positive for the first time as a result of the National Early Detection Survey of Forests, bringing the total number of positives to date for this year to 14. Both new stream positives are in urban areas with current or formerly positive nurseries in the vicinity. Stream baiting will continue in an effort to identify the inoculum sources. In addition, the eight eastern sites in MS, AL, GA, FL, and NC found positive in the past have been confirmed positive again in 2012.

from the July COMTF newsletter

Fourth genetic lineage of Phytophthora ramorum pathogen identified

The increasing intensity of the P. ramorum outbreaks in the UK led researchers to analyze samples from the new findings further, which resulted in the discovery of a fourth genetically distinct lineage of the pathogen.
Announcing this at the Fifth Sudden Oak Death Symposium in California recently, Clive Brasier, an emeritus professor with the Forestry Commission's Forest Research agency, said he believed, based on genetic analysis, that the previously unknown European Type 2 (EU2) lineage had been recently introduced into south-west Scotland and Northern Ireland.

Read the full article here