Managing Eastern Filbert Blight

Jay W. Pscheidt, Extension Plant Pathologist

When you first discover Eastern Filbert Blight (EFB) in your orchard it can be overwhelming. The disease typically has already been there for several years. What you see today is only the tip of the iceberg since there are many more infections that will not show up until the next year. Management of eastern filbert blight will require the use and integration of many tools by the hazelnut industry including scouting, spraying and pruning.

Scouting

Scouting for early detection is our most important activity for ALL hazelnut growers. Growers throughout the PNW must be as vigilant as growers in the Willamette Valley. It works! Scout your orchards at least twice a year. Even scout new resistant trees the year after planting.

Replace Pollinizers

Reducing the amount of susceptible tissue will reduce your EFB risk. Most of the industry had a medium risk with 'Daviana' pollinizers in 'Barcelona' orchards. Reduce your risk even more by replacing those susceptible trees. Don't wait for EFB to start. 'Ennis' orchards have the highest EFB risk because they are so susceptible. Removing wild seedlings and suppressing suckers early will also reduce your risk.

Apply Fungicides

Protecting healthy tissue is recommended for all orchards in the Willamette Valley. A total of 4 fungicide applications are needed starting at bud break (early to mid-march) and continuing at regular intervals (every 2 weeks depending on the weather and material used) for an 8 week period (until early May). This is the minimum spray requirement to consistently reduce the disease spread in orchards with established infections. Less than four applications increase the risk of continued spread of the disease. Fungicides are also recommended for resistant trees the first spring after planting.

Remove Cankers

Pruning is the ONLY way to remove EFB from the tree. Susceptible trees with many cankers MUST be removed. Resistant trees with one or two cankers can be lightly pruned (be sure to cut 1 to 3 feet below the visible canker).

Resistant Cultivars

Planting resistant cultivars is the easiest means of disease management. It does take some advanced planning, but is well worth the effort. Resistant selections are available from various nurseries. The cultivars 'Lewis', 'Clark', 'Gem' and 'Sacajawea' have quantitative resistance, while 'Santiam', 'Yamhill', 'Dorris', 'Wepster', 'McDonald', 'PollyO' and 'Jefferson' have a single dominant resistance gene from 'Gasaway'. Resistant pollinizers are also available for these new releases.