Oregon State University's integrated pest management program for the oregon hazelnut industry

Oregon State University (OSU) developed an integrated pest management (IPM) program for hazelnut (Corylus avellana.) in the early 1980s, through a USDA grant. Sampling schemes and action thresholds were refined over a period of 4 years for the filbertworm (Cydia latiferreana), filbert aphid (Myzocallis coryli), filbert leafroller (Archips rosanus.), and obliquebanded leafroller (Choristoneura rosaceana), which are the most important insect pests in Oregon hazelnuts. A classical biological approach was employed in the mid-1980s when the filbert aphid parasitoid, Trioxyspallidus, was imported from Europe. Grower survey results for 1981 and 1997 showed that the amount of pesticides applied for filbert aphid control has declined by 93%. The registration of synthetic pyrethroids; for filbertworm control and the use of pheromone trapping have reduced the amount of active ingredient applied in the industry by 96%. The annual cost savings to Oregon hazelnut growers due to use of the OSU IPM program are estimated at $0.5 million. Current research focuses on the use of less toxic insecticides, such as insect growth regulators for filbertworm and leafroller control. The most serious hazelnut disease, eastern filbert blight (EFB) caused by the fungus Anisogramma anomala was first reported in the Pacific northwestern U.S. in 1973. It has spread its way through two thirds of the hazelnut acreage. Current OSU IPM recommendations include preventative fungicide sprays in spring, scouting for and cutting out infections, and replacement of the most susceptible cultivars when possible. The long-term approach to EFB control is the development of EFB immune varieties.