Phytophthora ramorum research at the National Ornamentals Research Site at the Dominican University of California


Natural Sciences and Mathematics

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New Zealand Journal of Forestry Science

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Phytophthora ramorum Werres, De Cock & Man in‘t Veld, causal agent of sudden oak death (SOD) and ramorum blight, has been detected in container-grown plants, soil and irrigation ponds in various United States’ nurseries. Phytophthora ramorum has also been detected in runoff water from some nurseries and adjoining streams. Despite emergency regulatory actions, there is concern that P. ramorum infected nursery stock may further spread the disease in the United States of America (USA), particularly to previously unaffected wildlands. If established in the south-eastern USA, it could cause damage similar to that occurring in the coastal forests of California and Oregon. To develop solutions for nurseries that trade plants susceptible to P. ramorum, a quarantine nursery was established in Marin County, California, to investigate pathogen eradication and disease management. More than four years of collaborative efforts between the California Department of Food and Agriculture, California county Agriculture Commissioners, the California Oak Mortality Task Force, US National Plant Board, United States Department of Agriculture Animal and Plant Health Inspection Service Plant Protection and Quarantine and nursery industry resulted in locating a suitable site for developing the National Ornamentals Research Site (NORS) at the Dominican University of California (DUC). Funding to set-up and run the research nursery was awarded in 2008 through congressionally approved, Farm-bill (Section 10201) funding. The site is designed to perform research on quarantine pests and pathogens while safeguarding plant health and the surrounding natural environment. Research initiatives on P. ramorum have commenced at the NORS-DUC. Research grants are awarded to undertake research at the NORS-DUC and proposals can be submitted through


Based on a paper presented at the fifth meeting of the IUFRO working party S07-02-09, Phytophthora Diseases in Forests and Natural Ecosystems, 7 – 12 March 2010, Auckland and Rotorua, New Zealand.


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