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CORVALLIS - Researchers from Oregon State University are spearheading a new nationwide effort to limit the spread of sudden oak death in nurseries across the country.

The U.S. Department of Agriculture announced this week the formation of a Rapid Response Project to coordinate research and extension activities among several of the nation's universities and agencies.

Jennifer Parke, plant pathologist at Oregon's Agricultural Experiment Station, and C.Y. Hu, assistant director of the station, proposed the project in conjunction with colleagues at the University of California. The project connects researchers in several states for more rapid progress in managing the disease in nurseries.

The pathogen that causes sudden oak death affects far more than just oaks. Dozens of plants that define Oregon landscapes can harbor the pathogen, including rhododendron, madrone, camellia, viburnum, and huckleberry. Parke and her colleagues at OSU have found hundreds of other plants that are potentially susceptible, native as well as ornamentals. It is the threat to horticultural plants that has prompted creation of the Rapid Response Project by the USDA.

The United States is the world's largest producer and market for nursery and greenhouse crops, and the nursery and greenhouse industry is the fastest growing segment of U.S. agriculture, according to the USDA Economic Research Service. In terms of economic output, nursery and greenhouse crops represent the third most important sector in U.S. crop agriculture. Oregon's greenhouse and nursery industry is the state's largest grossing agricultural industry, and is second in the nation in the production of woody plants.

In March, 2004, several nurseries in southern California were found infested with the pathogen. Although the infected plants were destroyed at a cost of several million dollars, hundreds of thousands of plants potentially infected with the pathogen had already been shipped from the California nurseries to 39 other states. The pathogen has now been detected in several states. A federal quarantine has been put in place to prevent further shipments of infested nursery stock from California.

In addition to severe economic losses to the nursery industry due to crop losses and quarantines, the shipment of contaminated plants could transmit disease to gardens, parks and native vegetation throughout the U.S., according to Parke.

The pathogen that causes sudden oak death was first identified in 1993 in nursery plants in Germany and the Netherlands. It is now widespread in Europe, according to Parke.

OSU forest pathologist Everett Hansen discovered sudden oak death in forests in southwest Oregon in 2001 and since then has led an aggressive program to eradicate the disease. Hansen, Parke and fellow plant pathologist Bob Linderman, from the USDA Agriculture Research Service, have developed methods of diagnosis to understand more about this pathogen, how it spreads, how it infects plants, and how it can be controlled.

Working with researchers from the University of California, USDA and Oregon departments of agriculture and forestry, the OSU scientists created their own rapid response to sudden oak death. In California, where the disease first surfaced in 1995, the pathogen was too widespread to contain or eradicate by the time it was identified. By contrast in Oregon, rapid identification has made it possible to contain the disease and limit new cases, according to Parke.

The Rapid Response Project will bring researchers together from across the country to focus on ways to contain further spread of the pathogen and prevent its movement from nurseries to native vegetation.