Throughout September, if you drive the back roads of northwest Oregon you might see giant sweepers lumbering down the rows of hazelnut orchards, marshalling the nuts into long windrows then scooping them into bins. The nuts cooperate in their harvest by simply falling off the trees. Oregon produces 99 percent of hazelnuts grown in the United States. Oregon hazelnuts, among the largest of the world’s varieties and loaded with nutritious oils, are in demand throughout the U.S., Europe, and China.
But more than 20 years ago, the future of Oregon’s hazelnuts looked bleak. A fungal disease called eastern filbert blight had appeared in a few orchards in Washington and the northern Willamette Valley. Soon spores were blowing southward from infected areas, wiping out entire orchards and threatening the entire industry.
The disease is lethal to hazelnut trees and difficult to contain. Searching for a remedy, Oregon State University tree nut researchers set to work crossbreeding tree varieties for resistance to the disease. Breeding new tree varieties takes years, patience, and perseverance. Growers helped fund the research with more than $2 million through the Oregon Hazelnut Commission. The work paid off. All new varieties of hazelnuts that OSU has released since 2005 have genes that are resistant to the blight. And Shawn Mehlenbacher, head of OSU’s hazelnut breeding program, continues to develop new varieties with an even broader base of disease resistance.
“Eastern filbert blight has not been stopped,” said Jeff Olsen, an OSU Extension horticulturist who is helping hazelnut growers design and manage efficient orchards. “But we’ve kept production at a steady level by managing older susceptible varieties with pruning and fungicide sprays and by planting new orchards with new blight-resistant trees.”
In addition, growers are actively adopting pest management strategies that reduce the need for chemical applications. A successful strategy has been to import a wasp that controls filbert aphid populations, according to Polly Owen of the Hazelnut Marketing Board.
Healthy hazelnut trees can produce for 80 years or more, and sustainable agricultural practices can keep orchards in the family through generations. And now hazelnuts are becoming even more popular with consumers, especially with new evidence that their high antioxidant composition is similar to dark chocolate and grape juice.
In fact, chocolate and hazelnut would seem to be the candy lover’s dream combination. “We saw confection sales of hazelnuts go up 13 percent from 2007 to 2008,” Owen said. “And hazelnuts have cornered one-fifth of the nation’s gourmet chocolate market.” Sweet.