<p>It's a little known fact that Oregon is the US's main source of hazelnuts.</p> <p>It is estimated that 99% of the entire national crop is produced in the Willamette Valley. Yet just a few years ago the entire industry was threatened by Eastern filbert blight. Thankfully, years of dedicated research have ensured a supply of resistant varieties."It's just like cancer for trees, there's no real answer to it yet," says Tanner Koenig, a young farmer who grew up fighting blight. "It's just some of them have a 20-year lifespan left, some of them, it's five. Some orchards, we're taking trees out already."</p> <p>Growers initially struggled with the disease. For example, naturally enough, they cut out infected growth. All this did was sponsor new growth, which is more susceptible to infection than older wood.</p> <p>While farmers struggled to keep trees alive, researchers struggled to find a solution that would save the industry: a blight-resistant hazelnut. Shawn Mehlenbacher, professor of horticulture at Oregon State University, has been working on developing the resistant hazelnuts for more than 25 years.Developing new breeds is a long process and each new variety much pass several generations of crossing before being ready to test. After this it takes even longer to establish whether or not a variety is resistant.</p> <p>Mehlenbacher didn't start his work from scratch. The first cross-pollination to develop trees with blight resistance happened in the late 1970s. Scientists happened upon a blight-resistant pollinator in the fields, with a gene they named gasaway, and began the slow process of breeding trees that shared that resistance, as well as producing prolific, tasty nuts. By the time farmers were really hurting, OSU could offer plants that were not perfect, but had at least some resistance, taking longer to become stricken with blight.</p> <p>"The first release by the OSU breeding program that really had an impact on the industry was the Lewis breed, in 1997," Mehlenbacher says. "It was planted quite widely and kept the industry alive for another decade."</p> <p>The semi-resistant varieties served as a bridge for growers, keeping the industry ticking over until such a time as a completely resistant variety could be developed.Now, those trees are all over the Willamette Valley. Growers are putting their hope in them, replacing blighted trees with these new varieties.But some, like Rich Birkemeier, are just cutting the expense. This winter he's pulling up about 1,500 of the semi-resistant Lewis trees that have finally gone under and planting the new, fully resistant trees in their place.Birkemeier expects to see these new, blight-resistant trees still bearing nuts by the time his grandchildren are working the farm.</p>