Spring Barley Resistance and Tolerance to the Cereal Cyst Nematode Heterodera avenae

This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The American Phytopathological Society and can be found at: http://www.apsnet.org/publications/plantdisease/Pages/default.aspxHeterodera avenae is a cereal cyst nematode that reduces wheat yields in the Pacific Northwest\ud USA. Barley is also susceptible but there were no previous reports of resistance or tolerance to H.\ud avenae in the USA. Spring barley cultivars were assayed in H. avenae-infested fields over two\ud years. Cultivars were planted in plots treated or not treated with aldicarb. Forty-five cultivars were\ud evaluated for the market classes of 2- and 6-row feed barleys and 2- and 6-row malt barleys. One\ud 2-row feed barley (Lenetah) was ranked as resistant and four were tolerant or very tolerant. One 2-\ud row malt barley (Odyssey) was very resistant and 10 were tolerant or very tolerant. Two 6-row\ud feed and two 6-row malt barleys were tolerant or very tolerant but none were resistant. Seven feed\ud barleys were ranked as having a balance of at least moderate resistance plus moderate tolerance;\ud Champion, Lenetah, Xena, Idagold II, Transit, Millenium and Goldeneye. This is the first report of\ud resistance and tolerance of barley in H. avenae-infested fields in the Pacific Northwest. Barley\ud productivity can be improved by planting resistant plus tolerant cultivars or by using highly\ud resistant and highly tolerant cultivars as parents in barley improvement programs