EFB Killing Hazelnut Tree

Hazelnuts have been commercially produced in Oregon since the early 1900s when they were called “filberts.” In 1981, Oregon “filbert” growers began referring to their crop as “hazelnuts” to be consistent with the rest of the world. Oregon’s hazelnut orchards, concentrated in the Willamette Valley, account for 99% of US production and 5% of world production. Eastern filbert blight is a destructive disease of hazelnut trees that is only present in North America. The disease is known as eastern filbert blight because a shrub harbors the disease in the eastern US. In the 1920s, growers tried to start a hazelnut industry in New York. Filbert blight destroyed the trees. In 1974, the disease was found for the first time in Oregon and has spread throughout the Valley. Without fungicide sprays, the blight would kill the hazelnut trees.

“Eastern filbert blight (EFB) is caused by the fungus Anisogramma anomala…it causes severe perennial cankers, branch die-back, and eventual death of nearly all cultivars of the commercially important European hazelnut, C. avellana. …The pathogen was inadvertently introduced into southwestern Washington in the 1960s and devastated commercial hazelnut orchards because control measures were lacking at the time. It is now widespread across the Willamette Valley of Oregon, where 99% of the U.S. hazelnut crop is produced. Diligent scouting for cankers, extensive pruning, and copious fungicide applications are necessary to continue production in the presence of the fungus.”

Authors: Molnar, T. J., et al.
Affiliation: Department of Plant Biology and Pathology, Rutgers University.
Title: A real-time PCR assay for early detection of eastern filbert blight.
Source: Plant Disease. June 2013. 97[6]:813-818.