Jay W. Pscheidt, Extension Plant Pathologist
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 for early detection is our most
important activity for ALL hazelnut growers. Growers from
Eugene to Salem must be as vigilant as growers in the
greater Portland area. 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 has a medium risk with 'Daviana' pollinizers in
'Barcelona' orchards. Reduce your risk even more by
replacing those 'Daviana' 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.
Fungicides protect healthy tissue and are
recommended for all orchards in the Willamette Valley. A total of 4
fungicide applications are needed starting at budbreak
(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
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
Resistance 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' and 'Jefferson' have a single dominant resistance gene
'Gasaway'. Resistant pollinizers are also available for these new releases.
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