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Eastern filbert blight
Anisogramma anomala
Synonyms
 
None

Plant hosts
 
Corylus avellana (European hazelnut or filbert), C. americana (American hazelnut), C. contorta (contorted hazelnut), C. maxima, and other Corylus species. The two native species C. cornuta var. cornuta and C. cornuta var. californica and the Turkish hazelnut (C. colurna) appear to be resistant.

Symptoms
 
About 12- to 15-months after infection, symptoms first appear on branches and twigs as sunken brown cankers. The cankers expand in all directions, but primarily along the length of the infected branch. Raised pustules form within the cankers starting in June and eventually mature into black stroma (fungal fruiting bodies) around August to October. The stroma are raised about 1/10th of an inch above the branch. Cankers enlarge and coalesce along infected branches, eventually girdling the limbs. If left unchecked and depending upon the susceptibility of the variety infected, the trees will die within 7- to 15-years of becoming infected.
 
Image of eastern filbert blight
Image by OSU Extension

Transmission
 
The fungal stroma release spores in a sticky, white ooze in response to wet weather. Wind-driven rain and splashing droplets spread the spores to young, developing shoots. Spores may travel several miles via this pathway. The disease may also be spread through the movement of infected plant materials, primarily the movement of infected ornamental contorted hazelnut.

Geographic distribution
 
The disease is native to the East Coast of the United States and to Canada. It was introduced in the early 1990's into Washington and Oregon. 

Applicable regulations
 
At the request of the hazelnut industry, the ODA recently established a control area order for eastern filbert blight. The order is designed to protect Oregon from new, more virulent strains of A. anomala present in the east.
 
 
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