University of Missouri Extension

MX934, New April 2004

Sudden Oak Death

Editor's note
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The causal agent of sudden oak death (SOD, also known as Phytophthora canker disease), Phytophthora ramorum, was first identified in 1993 in Germany and the Netherlands on ornamental rhododendrons. P. ramorum was isolated in June 2000 from dying trees in California. Since its discovery in North America, P. ramorum has been confirmed in forests in California and Oregon and in nurseries in California, Oregon, Washington, and British Columbia.

SOD is not involved in the oak decline event that is currently being observed in Arkansas and Missouri. To date, no positive SOD samples have been confirmed in Missouri.

Foliar lesions Foliar lesions on Rhododendron vaseyi infected by P. ramorum.



MX934 Sudden Oak Death | University of Missouri Extension

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