NA2 lineage found on salal, additional positive nurseries

As part of the perimeter survey conducted at a P. ramorum-positive retail nursery in Pierce County, Washington last summer, the Washington State Department of Agriculture identified infested salal (Gaultheria shallon) plants in the natural landscape (as reported in the COMTF August 2009 Newsletter). Follow-up analysis of the samples by the Chastagner lab at Washington State University has resulted in the isolation of the NA2 lineage from the salal. This is the first detection of the NA2 lineage on native forest vegetation. For more information on this development, contact Gary Chastagner at chastag@wsu.edu.

Washington had two P. ramorum-positive locations identified in January. Both sites have previously been found positive for the pathogen. One positive find was in retention pond water at a Pierce County retail nursery. Treatment of the pond (located on nursery property) is optional as it is not used for irrigation or fire suppression. The second site was in a Mason County church landscape where an assumed-positive Viburnum tinus was identified as part of a Thurston County nursery trace-forward investigation. Follow-up efforts have determined that the viburnum did not transit through the Thurston County nursery, but rather was sourced from Oregon. It is unknown where the plant potentially became infested. The Oregon nursery from which the plant originated completed the CNP in December (2009). WSDA PCR results on the viburnum were inconclusive; results are pending from Beltsville, MD.

From the February COMTF newsletter