Country: United States

Title: Additions to APHIS List of Hosts and Plants Associated with Phytophthora ramorum

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On 14 February 2002, APHIS published an interim rule in the Federal Register for Phytophthora ramorum (7 CFR 301.92).  This rule restricts the movement of certain restricted and regulated articles to prevent the artificial spread interstate of this disease-causing organism from areas where the disease is established. APHIS also issued an Emergency Federal Order dated 21 December 2004 to regulate certain nurseries and plants to prevent the spread of the pathogen through nursery plants. The USDA has now learned that certain additional plants require regulating in order to control the artificial spread of this disease. The purpose of this SPRO is to provide notification that APHIS is listing ten new plants and establishing an interim policy for incorporating these into the Federal Order.

 

The USDA received information from the Department of Environment, Forestry, and Rural Affairs (DEFRA) of the United Kingdom that they had officially identified five new plants associated with P. ramorum.  These are: Hamamelis mollis – Hamamelidaceae (Chinese witch-hazel), Magnolia stellata – Magnoliaceae (star magnolia), Magnolia x loebneri – Magnoliaceae (Loebner magnolia), Magnolia x soulangeana – Magnoliaceae (saucer or Japanese magnolia), and Acer pseudoplatanus – Aceraceae (Planetree maple).

 

The USDA received information from the Plant Protection Service of the Netherlands that they had officially identified one new plant in their nursery survey associated with P. ramorum. This is: Taxus media –Taxaceae (Yew).

 

A California researcher has alerted us that two plants found established in a park in the infested area of California demonstrated symptoms and has been determined to be infected with P. ramorum. These two plants are: Adiantum californica – Polypodiaceae (California maidenhair fern) and Calycanthus occidentalis – Calycanthaceae (spicebush).

 

Therefore, these plants are now listed in the APHIS List of Hosts and Plants Associated with Phytophthora ramorum. Effective immediately the following are associated regulated articles which will be listed in 7 CFR 301.92 and in PPQ orders restricting the movement of nursery stock to prevent the spread of P. ramorum:

 

·         Acer pseudoplatanus - Aceraceae (Planetree maple)

o        Medium sized tree native to Europe and western Asia

o        Bole canker

 

·         Adiantum jordanii – Polypodiaceae (California maidenhair fern)

o        Perennial fern native to US West coast

o        Leaf blight

 

·         Calycanthus occidentalis – Calycanthaceae (spicebush)

o        Deciduous shrub native to western coastal states

o        Leaf blight and dieback

 

·         Hamamelis mollis – Hamamelidaceae (Chinese witch-hazel)

o        Small tree from China;

o        Koch’s postulates not completed

o        Leaf blight and dieback

 

·         Magnolia stellata – Magnoliaceae (star magnolia)

o        Small tree from Japan

o        Koch’s postulates pending

o        Leaf blight

 

·         Magnolia x loebneri – Magnoliaceae (Loebner magnolia)

o        Ornamental tree , a hybrid from a cross between M. kobus and M. stellata

o        Koch’s postulates pending

o        Leaf blight

 

·         Magnolia x soulangeana – Magnoliaceae (saucer or Japanese magnolia)

o        Shrubby hybrid, the parents of this hybrid are M. heptapeta and M. liliiflora which are both native to Japan

o        Koch’s postulates pending

o        Leaf blight and dieback

 

·         Taxus media – Taxaceae (Yew)  

o        Evergreen shrub, the parents of this hybrid are Taxus baccata and                   T. cuspidata]

o        Basal stem canker

 

In addition, two new plants have been identified as new hosts for which Koch’s postulates have been completed.  The USDA received information from the Department of Environment, Forestry, and Rural Affairs (DEFRA) of the United Kingdom that they have officially identified two new plants infected with P. ramorum and completed Koch’s postulates. These are: Griselinia littoralis – Cornaceae (Griselinia), and Parrotia persica – Hamamelidaceae (Persian Parrotia or irontree). Therefore, these plants are now listed in the APHIS List of Hosts and Plants Associated with Phytophthora ramorum and effective immediately are regulated articles which will be listed in 7 CFR 301.92 and in PPQ orders restricting the movement of nursery stock to prevent the spread of P. ramorum:

 

·         Griselinia littoralis – Cornaceae (Griselinia)

o       Hardy privet-like hedge

Posted Date: Aug. 4, 2005, 9 a.m.