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An update on Phytophthora ramorum in European nurseries

Informally Refereed
Download (PDF 33 KB): https://research.fs.usda.gov/download/treesearch/29783.pdf

Abstract

Emergency phytosanitary measures to prevent the introduction into and spread within the European Union (EU) of Phytophthora ramorum Werres, De Cock & Man in 't Veld. have been in place since 2002. Surveillance across the EU, has confirmed the presence of P. ramorum on nurseries and retailers in 15 member states. Phytophthora ramorum has been confirmed on 14 plant genera at nurseries and retailers, with 96 percent findings being made on Rhododendron, Viburnum and Camellia, which are the three genera currently regulated for internal movement within the EU. More detailed analysis of data from England and Wales shows that rigorous enforcement of the emergency measures can result in very encouraging reductions in compliance infringement both in terms of documentary errors and findings of P. ramorum on certificated material. Furthermore, the percentage of inspections positive for P. ramorum and the number of outbreaks at nurseries and retailers has shown similar and encouraging reductions between 2002 and 2006. P. ramorum has, however, continued to be found in the EU on commercially-traded plants, which indicates that the emergency phytosanitary measures have not been completely effective. Any future revisions to the measures need to take account not only of emerging results from on-going research and surveillance but also of compliance costs to official services and to the commercial nursery stock industry in relation to benefits.

Parent Publication

Citation

Slawson, David; Blackburn, Jennie; Bennett, Lynne. 2008. An update on Phytophthora ramorum in European nurseries. In: Frankel, Susan J.; Kliejunas, John T.; Palmieri, Katharine M., tech. coords. 2008. Proceedings of the sudden oak death third science symposium. Gen. Tech. Rep. PSW-GTR-214. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. pp. 31-34