Eastern Filbert Blight

Eastern Filbert Blight Help Page

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Helping farmers find, destroy, and manage EFB

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Below you will see two different maps showing the progress of eastern filbert blight through the main hazelnut production areas of the Pacific Northwest from 1958 to 2005. The survey map on the right shows the location of infected orchards or nursery stock as they were actually discovered. The biology map on the left shows the same information but modified to when we think infection occurred. The location of infected orchards is displayed as red dots while the location of infected ornamental or orchard stock is shown as blue dots which disappear.
Map by Jay Pscheidt and Pat Grimaldi, 2006.

The animated maps will play automatically for just under 2 minutes once this page is displayed. (It may not play correctly if you do not have the latest version of "flash payer" installed. You may also need to restart your browser after the download is complete.) The animation will stop when it reaches 2005. You may play the animation again by clicking on the "Restart maps" button. You can pause the animation at any time by clicking on the "Stop" button. Then you can resume the animation by clicking on the "play" button or move backward or forward in time one year by clicking on the "Back 1 year" or "Forward 1 year" buttons.
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Notable events concerning Eastern Filbert Blight in the Pacific Northwest.
It was thought that EFB was imported from the eastern USA on infected nursery stock (Dr. Ron Cameron, Personal Communication).
Based on disease severity, it was thought EFB started in commercial trees about this time (4).
EFB subsequently spread to other commercial orchards but went unnoticed for several years and unrealized for many more.
Washington state hazelnut grower first noticed EFB in his orchard but took no action for 2 years (3).
Independently, county agents from Oregon and Washington send a canker disease from infected commercial hazelnut orchards to OSU and WSU plant clinics. Samples were correctly identified by both institutions but overall importance not realized by anyone (1, 12).
Using a few twig samples collected by the local county agent, it was realized that EFB was new to the PNW and reported in a scientific journal by WSU's Dr. Arlen Davison and Dr. Roy Davidson, Jr. (3, 12).
Hazelnut USDA researcher Dr. Harry Lagerstedt found EFB well established in Washington orchards (1, 12). Big bud mite found associated with EFB cankers and experiments were begun late that year to see if there was a connection (1). Oregon Dept. of Ag. inspections found two infected orchards in Columbia County Oregon west of St. Helens, OR. On 22 Nov 1974, Oregon's quarantine was amended to include Washington State and Columbia County (1).
Surveys showed that EFB was well established over a 200 square mile area and that eradication would be impossible. Field observations found that the pollenizer 'Daviana' was very susceptible while the main nut producing cultivar 'Barcelona' was much less susceptible. The poor nut producing pollenizer 'Gasaway' appeared resistant (1).
'Ennis' was determined to be susceptible to EFB (12). At this time there have been 36 commercial orchards found with EFB.
Trying to make sense of field data, graduate student Tim Gottwald and OSU Professor Dr. Ron Cameron realized that the EFB fungus has a two year life cycle (5).
A total of 49 commercial orchards have been found with EFB and 9 have been removed. Experimental data confirmed that EFB has a two-year life cycle. It was further concluded that buds blasted by the big bud mite are the site of ascospore infection. It was also stated that no chemical measure has been found for the control of this canker disease (5).
Recommendations based on trials from mature 'Daviana' trees called for the use of the copper -based fungicides bordeaux or Kocide during late November or early December and again before March 1st for control of this disease. Also recommended for EFB control was the use of Thiodan against big bud mite (2, 13). It was reported at a National APS Meeting that a combination of canker removal and the application of mancozeb 5 times each year reduced EFB in a small orchard in Virginia. This abstract seemed to go unnoticed in the PNW for almost a decade (11).
Chemical control trials from 1976-1982 on mature 'Daviana' trees showed that only copper-based fungicides (mostly bordeaux) applied during the dormant season and early spring provided significant and consistently fewer EFB cankers (unpublished data by Dr. Ron Cameron (see letter to Lorna Youngs).
Gassaway was shown to have a single dominate gene for resistance against EFB by OSU Assistant Professor Dr. Shawn Mehlenbacher and Professor Dr. Maxine Thompson (14).
In late 1986, EFB was found in an orchard near Gresham, OR in northern Clackamas County several miles south east of the original Washington State infection area (17).
Surveys by ODA found EFB in 37 commercial orchards, 36 unmanaged orchards and 217 residential trees in Northern Clackamas County, Oregon (17). Analysis of several orchards showed that secondary disease spread in an orchard occurred to the north-northeast of initially infected trees (16, 17, 18).
Nov 1987, a new fungicide trial established in Zimmerman's orchard by OSU Washington County Extension Agent Craig Riggert and Dr. Ron Cameron using young healthy trees was sprayed during the dormant season with various fungicides with the last spray before budbreak 1988 (23). ODA surveys from 1988-1990 showed 326 sites with EFB widely scattered through Washington, Multnomah and Clackamas Counties (about 2,300 square miles including Clark County Washington). The greatest concentration and most severely diseased orchards were in northern Clackamas county.
So many EFB cankers developed in the new fungicide trial that most people considered it a failure. However, OSU Assistant Professor Dr. Jay Pscheidt noticed that the best trees were all treated with Bravo. Subsequent data analysis shows that only Bravo significantly reduced cankers (23). OSU Professor Dr. Dick Smiley found an EFB canker in his home grown contorted filbert near Pendleton, OR. Subsequent trace backward inspections by ODA found that this tree originated from a commercial whole sale nursery near Portland, OR and trace forward inspections found shipments of infected trees into Eugene, OR. (19).
Experiments by OSU's Dr. Ken Johnson and Dr. Jeff Stone proved that hazelnuts are infected by the fungus through juvenile tissues during bud break and early shoot growth (7, 25). First emergency label (section 18) for use of Bravo 720 (chlorothalonil) was granted by EPA for control of EFB on hazelnut (8).
Formal release of 4 hazelnut pollenizers, the VR series, that had the Gassaway gene for resistance (15).
Growers in all areas were encouraged to scout for the disease but growers south of an east-west line at Woodburn, OR were not encouraged to use fungicides based on survey results to date (24).
Several fungicides were effective against EFB and programs have been established for its control (6, 9, 10).
First emergency label (section 18) for use of Rubigan (fenarimol) for control of EFB on hazelnut, however, before growers could it they had to sign a Waiver of Liability. Emergency use of Bravo also still granted annually (8).
Dr. Pscheidt predicts continued spread into the southern Willamette Valley based on grower survey results showing 25% of the growers who said they did not have EFB also did not do any scouting (21). Due to continued discovery of infected contorted filberts south of the generally infested area, an emergency quarantine was issued by Oregon restricting retail sales of Corylus sp. within the state (19).
Discovery of EFB around Woodburn, OR moved the area thought of as generally infested to north of Salem, OR. Growers south of this area were still not encouraged to use fungicides (24).
Many fungicides have been found to be effective against EFB with registration the only limitation for commercial use (20, 22).
Discovery of EFB near Keiser, OR prompted a recommendation for all growers, especially of the highly susceptible cultivar 'Ennis' to use fungicides (24).
Application for use of the fungicide Orbit (propiconazole) denied but use of Rubigan still granted.
First emergency label (section 18) for use of Elite 45 DF (tebuconazole) granted by EPA for control of EFB on hazelnut. EFB found in an orchard adjacent to the USA, Canadian boarder near Lynden, WA.
Application for use of the fungicide Procure (triflumizole) denied but use of Elite still granted.
Application for use of the fungicide Elite denied but use of Procure granted. EFB found in non-orchard hazelnuts in southern British Columbia, Canada.
First emergency label (section 18) for use of Orbit (propiconazole) granted by EPA for control of EFB on commercial orchards of hazelnut.
Formal release of the cultivar Santiam, a commercial quality hazelnut that had the Gassaway gene for resistance.


  1. Cameron, H. R. 1976. Eastern filbert blight established in the Pacific Northwest. Plant Dis. Rep. 60:737-740.
  2. Cameron, H. R. and Gottwald, T. R. 1978. Progress report on Eastern filbert blight. Proc. Nut Growers Soc. of OR, WA & BC 63:522-523.
  3. Davidson, A. D. and Davidson, R. M. 1973. Apioporthe and Monochaetia canker reported in Western Washington. Plant Dis. Rep. 57:522-523.
  4. Gottwald, T. R., and Cameron, H. R. 1980. Disease increase and dynamics of spread of canker caused by Anisogramma anomala in European filbert in the Pacific Northwest. Phytopathology 70:1087-1092.
  5. Gottwald, T. R., and Cameron, H. R. 1980. Infection site, infection period, and latent period of canker caused by Anisogramma anomala in European filbert. Phytopathology 70:1083-1087.
  6. Johnson, K.B. and Pscheidt, J.W. 1993. Development of a control program for eastern filbert blight. Proc. Nut Growers Soc. of OR, WA & BC 78:84-87.
  7. Johnson, K.B., Pinkerton, J.N., Gaudreault, S.M., and Stone, J.K. 1994. Infection of European hazelnut by Anisogramma anomala: Site of infection and effect of host developmental stage. Phytopathology 84:1465-1470.
  8. Johnson, K.B., Pinkerton, J.N., Mehlenbacher, S.A., Stone, J.K, and Pscheidt, J.W. 1996. Eastern filbert blight of European Hazelnut: It's becoming a manageable disease. (feature) Plant Dis. 80:1308-1316.
  9. Johnson, K.B., Pscheidt, J.W., and Pinkerton, J.N. 1993. Evaluation of chlorothalonil, fenarimol, and flusilazole for control of eastern filbert blight. Plant Dis. 77:831-837.
  10. Johnson, K.B., Pscheidt, J.W., Theiling, K.M., and Pinkerton, J.N. 1991. Systemic fungicides for control of eastern filbert blight, 1990. Fungicide and Nematicide Tests 46:96.
  11. Kosztarab, M., Roane, M.K., and Drake, C.R. 1980. Reduction of eastern filbert blight on Corylus avellana. (abstract) Phytopathology. 70:690.
  12. Lagerstedt, H.B. 1979. A review of observations and research on eastern filbert blight in the Pacific Northwest. Ann. Rpt. No. Nut Growers Assoc. 70:22-30.
  13. MacSwan, I. C. and Koepsell, P. A. Senior editors. 1980. Pacific Northwest Plant Disease Management Handbook. Oregon State Extension Service.
  14. Mehlenbacher, S. M., Thompson, M.M. and Cameron, H.R. 1991. Occurrence and inheritance of resistance to eastern filbert blight in Gasaway hazelnut. HortScience 26:410-411.
  15. Mehlenbacher, S.M. and Thompson, M.M. 1991. Four hazelnut pollenizers resistant to eastern filbert blight. HortScience 26:442-443.
  16. Pinkerton, J.N. 1999. Eastern Filbert Blight: Spore dispersal and spread. Proc. Nut Growers Soc. of OR, WA & BC 84:33-39.
  17. Pinkerton, J.N, Johnson, K.B., Theiling, K.M., and Griesbach, J.A. 1992. Distribution and characteristics of the eastern filbert blight epidemic in western Oregon. Plant Dis.76:1179-1182.
  18. Pinkerton, J.N., Johnson, K.B., and Stone, J.K. 1998. Maturation and seasonal discharge pattern of ascospores of Anisogramma anomala. Phytopathology 88: 1165-1173.
  19. Pscheidt, J. W. 1996. Contorted Filberts: A Threat to Oregon's Hazelnut Industry! Digger 40(4):13.
  20. Pscheidt, J. W. 1999. Eastern Filbert Blight: Fungicides for control. Proc. Nut Growers Soc. of OR, WA & BC 84:47-56.
  21. Pscheidt, J. W. and Cluskey, S. 1996. Eastern filbert blight management survey. Proceedings of the Nut Growers Society of Oregon, Washington and British Columbia. 81:53-60.
  22. Pscheidt, J. W. and Cluskey, S. 2001. Fungicide Control of Eastern Filbert Blight. Acta Horticulturae 556:411-417.
  23. Pscheidt, J.W., Johnson, K.B., and Cameron, H.R. 1990. Comparison of fungicides for control of eastern filbert blight, 1989 season. Fungicide and Nematicide Tests 45:86.
  24. Pscheidt, J.W. and Ocamb, C. M. Senior editors. Pacific Northwest Plant Disease Management Handbook. Oregon State Extension Service.
  25. Stone, J.K., Johnson, K.B., Pinkerton, J.N., Pscheidt, J.W. 1992. Natural infection period and susceptibility of vegetative seedlings of European hazelnut to Anisogramma anomala. Plant Dis. 76:348-352.
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