OREGON STATE UNIVERSITY
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EUGENE - Eastern filbert blight fungus was found by two hazelnut growers, one in north Albany on July 1, and another in south of Coburg on July 8.
"The discovery of this devastating disease is a shock and a blow to the hazelnut growers in the south valley," said Ross Penhallegon, horticulturist with the Lane County office of the Oregon State University Extension Service. "The growers have been diligently trying for years to prevent the disease from moving south."
The discovery of the blight (Anisogramma anomala), also known simply as EFB, has the potential to affect more than 28,000 acres of hazelnuts in Oregon, valued at more than $23 million.
The disease was first discovered in Oregon in the mid-1970s. In 1999 it was discover in north Keizer. Intensive control and monitoring efforts have been in place since then to keep track of the disease and quickly move to halt it if another outbreak occurred.
Since 1999, the disease seemed to have been thwarted, said Penhallegon, making the July discoveries all the more devastating.
"The Willamette Valley community has made a valiant effort in finding and destroying 21 infected contorted filbert trees since May 1990," said OSU's Penhallegon, who has worked with nut growers and home gardeners for more than two decades. "But with these new discoveries, growers in the south valley will have to take a new approach to the disease, including intensive monitoring, chemical control, and tree removal and replacement."
Eastern filbert blight has been in the orchards of western Oregon for at least five years, according to Jay Pscheidt, Extension plant pathologist in OSU's Department of Botany and Plant Pathology.
How did this disease get to western Oregon?
"So far, there are no good answers," said Penhallegon. "The (possible) transfer of the disease by birds, wind, rain, nursery stock and equipment have all been dismissed as being the reason for the spread of this fungal disease."
Commercial hazelnut growers will be most affected by the outbreak, he said. They are setting up an intensive monitoring program, especially of 'Ennis' and 'Daviana' cultivars, said Penhallegon. Orchards with disease-susceptible cultivars may be removing those trees after the end of the current nut season. The Oregon Department of Agriculture will be doing spot survey work for EFB this winter.
According to Penhallegon, control strategies include partial to complete tree removal, tree replacement, pollinizer replacement and chemical fungicide applications. Financial impacts to growers with infected trees may be serious and include costs for control, replacement and decreased yields, he warned.
Hazelnut growers without infected trees will also feel the impact, he said.
"They will need to continue to inspect and monitor orchards for disease, remove non-resistant trees and plant resistant cultivars," he said. "They will also need to spray fungicides one to three times per year."
The OSU/Lane County Extension Service, Oregon Hazelnut Commission and the Oregon Nut Growers Society will hold an information session on Friday, July 25, beginning at noon at the OSU/Lane County Extension office, 950 West 13 Ave. in Eugene to discuss the discovery of Eastern Filbert Blight in Lane and Linn counties. Hazelnut experts will be on hand to answer questions on potential industry consequences, control methods, options available to growers and the public and potential future EFB resistant nut tree varieties.
In addition, the Lane County office of the OSU Extension Service has planned two grower field tours for Aug. 20-21 to inform the growers about EFB and to teach them how to scout and identify the disease. Specimens with the disease, information and color photos will be available. Contact the Lane County office for more information, closer to the field day dates.
For more information, contact:
Ross Penhallegon, 541-682-4243
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