Country: United States

Title: Listing and Regulation of Plants Recently Reported with Phytophthora ramorum

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Report: On February 14, 2002, APHIS published an interim rule in the Federal Register for Phytophthora ramorum (7 CFR 301.92). This rule regulates the interstate movement of restricted and regulated articles to prevent the artificial spread of this disease-causing organism from areas where the disease is established. APHIS also issued an Emergency Federal Order dated December 21, 2004, to regulate certain nurseries and plants to prevent the spread of the pathogen through nursery plants.

The purpose of this Official Pest Report is to provide notification that APHIS will be regulating certain new species, effective February 20, 2006. This action is necessary as APHIS has learned that:
•Certain additional plant taxa can be infected by P. ramorum and need to be regulated in order to control the artificial spread of this disease (see summary below).
•Koch’s postulates have been completed on three species (Frangula purshiana (formally listed as Rhamnus purshiana), Adiantum aleuticum, and Adiantum jordanii), therefore they have been moved from the list of “plants associated with Phytophthora ramorum” to the list of “proven regulated hosts”.
•Nomenclature of host species needed revision in order to clearly communicate what plants are under regulation.

An important note for the record; Canada detected a naturally infected Rhododendron species which has the characteristics commonly applied to azaleas. Though APHIS has regulated all Rhododendron species since 2002, this is the first documented incident of naturally infected “azalea”.

The new Federal Domestic Quarantine Order reflects information received from Washington State University and the Canadian Food Inspection Agency which identified plants associated with P. ramorum not previously reported. Washington State reported Abies magnifica – Pinaceae (red fir) and Canada reported twelve new species, listed below. Koch’s Postulates have not yet been completed for these plants, so they can not yet be listed as proven hosts of P. ramorum.

The plants added are: Abies magnifica (Pinaceae)**, Acer davidii (Aceraceae )*, Ardisia japonica (Mysinaceae)*, Euonymus kiautschovicus (Celastraceae)**, Gaultheria shallon (Ericaceae)*, Hamamelis x intermedia (H. mollis & H. japonica) (Hamamelidaceae)*, Leucothoe axillaris (Ericaceae)*, Magnolia grandiflora (Magnoliaceae)*, Michelia maudiae (Magnoliaceae)*, Michelia wilsonii (Magnoliaceae)*, Osmanthus decorus (=Phillyrea decora; =P. vilmoriniana) (Oleaceae)*, Prunus lusitanica (Rosaceae)*, Rosa rugosa (Rosaceae)*
Symptoms-
*leaf blight
**leaf blight, tip dieback

As an interim measure, these plants are added to those under regulation as per PPQ Emergency Federal Order (Order) dated December 21, 2004, affecting the movement of nursery stock from the States of Washington, Oregon and California. Those nurseries operating under a compliance agreement may continue to ship Hosts and Associated Plants including the newly listed plants. Any other nurseries containing these newly listed associated plants must be properly inspected, sampled and tested and placed under a Compliance Agreement by February 27, 2006 to be able to move plants interstate.

This action is authorized by the Plant Protection Act of June 20, 2000, as amended, Section 412(a), 7 U.S.C. 7712(a), which authorizes the Secretary of Agriculture to prohibit or restrict the movement in interstate commerce of any plant, plant part, or article if the Secretary determines the prohibition or restriction is necessary to prevent the dissemination of a plant pest within the United States.

The current “APHIS List of Regulated Hosts and Plants Associated with Phytophthora ramorum” is available online at: http://www.aphis.usda.gov/ppq/ispm/pramorum/pdf_files/usdaprlist.pdf.
 

Posted Date: Feb. 13, 2006, 9 a.m.