Nursery update

To date in 2012, the US has had 32 P. ramorum-positive nurseries in seven states (CA-6; OR-11; WA-10; NC-1; ME-1; NY-2; PA-1) as well as 4 positive residential/ landscape detections (CA, OR, WA, ME). Positive plants included: Rhododendron (51%); Camellia (13%); Viburnum (11%); Pieris (7%); Kalmia (3%); Gaultheria (4%); Loropetalum (3%); Magnolia (3%); Hamamelis (2%); Cornus (1%); Prunus (1%); and Trachelospermum (1%). Seventeen of the positive nurseries are interstate shippers (CA-2; OR-7; WA-7; NY-1) and 15 are retail facilities (CA-4; OR-4; WA-3; NC-1; ME-1; NY-1; PA-1). Collection ponds were positive at 2 retail nurseries (WA, NY) and 3 that ship interstate (2-WA, 1-NY). Soil was positive at 1 retail nursery (CA), 2 interstate shipping nurseries (CA, OR), and 1 landscape site (WA). Ten interstate trace-forward investigations were conducted this year: three with potentially infected plants shipped to 24-30 states and seven with potentially infected plants shipped to 1 to 3 states. As a result, P. ramorum was detected at retail nurseries in ME and PA that were shipped from OR, and from three residential/landscape sites in OR, WA, and ME that originated in WA. Confirmed Nursery and/or Residential Protocols are being implemented at all locations.

From September 2012 COMTF newsletter

Water treatment research at WSU

The Chastagner lab at Washington State University, Puyallup plans to develop a biofiltration testing facility and determine the effectiveness of several techniques for removing P. ramorum inoculum from water. Methods similar to those being used for remediating stormwater are being considered for removing pathogen inoculum from nursery runoff and will have the added advantage of removing pollutants. These methods will consist of biofilters using various organic substrates, constructed wetlands or rain gardens, and physical methods such as sand filtration or sedimentation. Pilot biofiltration systems will be installed at selected P. ramorum-positive nurseries in Washington and be part of a training program for nursery managers. A Best Management Practices workshop will also be held for nursery managers regarding the installation and maintenance of cost-effective biofiltration systems for removal of Phytophthora inoculum in water. Funding for the project has been made possible by the Farm Bill and the Washington State Department of Agriculture Nursery Research Program.

From Sept. 2012 COMTF newsletter

Questions? Comments? Email Marianne Elliott