Country: United States

Title: Boxwood Rust (Puccinia buxi) incident in Pennsylvania

Contact:
<p>Dr. Vedpal S. Malik at (301) 734-6774 or via email at: <a href="mailto:vedpal.s.malik@usda.gov">vedpal.s.malik@usda.gov</a><br/>or Dr. Anwar Rizvi at  (301) 734-4313or via email at: <a href="mailto:anwar.s.rizvi@usda.gov">anwar.s.rizvi@usda.gov</a>.</p

Report:

In the summer of 2005, a nursery in Pennsylvania received a shipment of boxwood (Buxus sempervirens) cuttings representing a number of collections from various locations in Greece.  These cuttings were inspected in Greece and a phytosanitary certificate was issued.  Since arriving at the Pennsylvania nursery, these cuttings have been in greenhouses and, most recently, in cold frames.  None have been planted outside.  In the spring of 2006, rooted cuttings from several accessions in this collection showed symptoms of boxwood rust caused by Puccinia buxi.  Nursery staff identified the pathogen as Puccinia buxi by examining the teliospores microscopically and comparing them with teliospore images on the web.  On May 5, 2006, USDA Animal Plant Health Inspection Service's National Identification Services, confirmed the pathogen as Puccinia buxi.

Also on May 5, 2006, USDA Plant Protection and Quarantine issued an Emergency Action Notice to the Pennsylvania nursery.  Thirty-five plants infected with Puccinia buxi were bagged and destroyed by autoclaving.  The nursery is making a list of the other asymptomatic boxwood plants that were near the infected plants.  The asymptomatic plants currently are quarantined in a cold frame.  The infected plants in question are native to Greece and the cuttings were gathered in the wild.  They were not obtained from a commercial source; therefore, there is no record of sale.  The Pennsylvania nursery has not shipped any of the plants in question to any other locations in the United States.

A Maryland nursery also acquired cuttings of boxwood from Greece.  The owner of that nursery has been notified of this problem.  All boxwood plant materials that were obtained from Greece will be placed under post-entry quarantine for 6 months, while the USDA’s Center for Plant Health Science and Technology develops an action plan for eradicating this pest.  Fungicide sprays should be prohibited during this post-entry quarantine because the fungicides can suppress symptoms and the disease.  The distribution of asymptomatic plants could spread the disease across the United States.

Posted Date: May 16, 2006, 9 a.m.