Eastern Filbert Blight Management Program

The research blocks are being used to grow inoculum wood—infected branches that can be use in infection experiments.
The research blocks are being used to grow inoculum wood—infected branches that can be use in infection experiments.
Eastern Filbert Blight (EFB)
Eastern Filbert Blight (EFB)

Oregon is the largest producer of filberts in the world—except for the Mediterranean region. Eastern Filbert Blight is a disease that threatened to wipe out our industry in the 1980s and 90s. OSU's Eastern Filbert Blight Management program has worked to develop the tools needed to control this fungal disease in our state. In addition, researchers are trying to better understand the limitations of these tools and integrate them into an effective disease management program for hazelnut growers of the Pacific Northwest.

The Eastern Filbert Blight (EFB) project at NWREC started in 1987 when the disease first appeared in Oregon's main production areas. The location for the research and trials has changed several times from grower orchards in the north to OSU's experiment stations and farms to the south. The projects and activities have moved as the disease moved from north to south in the Willamette Valley. The NWREC project began in 2001 and has been there since. The research blocks at NWREC are being used to grow inoculum wood—in other words, infected branches than can be use in infection experiments conducted at the OSU Botany & Plant Pathology Research Laboratory in Corvallis. The NWREC project location has been a very useful location and critical for fine tuning the EFB management program. As new resistant cultivars are released by OSU's breeding program the need for this research will decline.

Annual testing of various chemical and biological fungicides has helped find cheaper and more effective products, avoided unnecessary applications of ineffective products and has generated data directly responsible for the successful application and generation of emergency use, special local needs and full use labels. Over 28 different fungicides are now labeled for use on hazelnuts to combat this disease.

At the request of growers, pruning recommendations were modified based on research into the severity of pruning cuts to rid trees of EFB cankers. An education program has incorporated 35 years of survey data into disease progress maps to help educate growers about disease spread.

Several ideas have been researched but proved ineffective for EFB control and thus have avoided unproductive disease management activities. Injection of infected trees with fungicides was one of these ineffective ideas. The development of a forecasting system, GrammaCast, helped time fungicide applications. Although the system saved fungicide applications over a multi year period, it resulted in increased disease levels over standard recommendations. Biological control of EFB may be possible, but not without many more years of development.

Details of EFB from life cycle, disease spread, to fungicide effectiveness can be found online at the Eastern Filbert Blight Help page.


Jay W. Pscheidt
OSU Extension Plant Pathology Specialist
Oregon State University, Corvallis, OR