Nov 22

Hazelnut breeding for disease resistance and climate adaptation

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Oregon produces 99% of US commercial hazelnuts, with farmgate sales at $60-75 million. Oregon hazelnuts attract a premium price for large nuts compared to any other production area. Commercial plantings began in 1905; the area planted to hazelnuts reached 29,000 acres in 1986 when eastern filbert blight (EFB) was found in Clackamas County, OR.

Chemical control of EFB costs $160/acre/year. Scouting and removal of infected branches is an additional $150/acre/year. Infected trees experience dramatic yield reduction as they gradually die. From 1986 to 2010, new orchards were planted (mostly ‘Lewis’) and old diseased orchards were removed, and the total acreage remained at 29,000 acres. About 70% of orchards are infected, or are close to diseased orchards.

The goal of this SCRI-funded project is to develop disease-resistant hazelnuts, develop varieties adapted to nut production in eastern North America, and develop varieties providing Midwestern growers with an additional biofuel enterprise. The ‘Gasaway’ gene confers resistance to EFB. It is fully mapped and characterized, although work continues to refine our understanding of its function. Cultivar ‘Jefferson,’ EFB resistant and valued for its large nuts, is being readily adopted.

Beginning in 2010, plantings have expanded at a rate of 3000 acres per year with availability of new resistant cultivars. Continued research will identify and study new sources of resistance, and use them to develop new cultivars with stable resistance. Hazelnuts provide an alternative enterprise to the Willamette Valley’s grass seed growers, who continue to suffer from stagnant markets since the fall of the housing market in 2008. In a fully establishment orchard, EFB resistant trees return $1,940 per acre over cash costs to the grower, as compared to -$3,014 for the EFB susceptible planting, a difference in cumulative cash flow of $4,954 per acre. China is the principal export market for US hazelnuts.