The 2012 ASHS Annual Conference

The European hazelnut (Corylus avellana) has a large nut and has potential as a new crop for small farmers in Kentucky for both in-shell nut sales at farmers’ markets and shelled nuts in value-added products. Susceptibility to eastern filbert blight (EFB) has limited the past use of European hazelnut cultivars in this region. Recently released hazelnut varieties from Oregon State University have high resistance to EFB and could serve as potential new cultivars for the region. The objective of this study was to examine regional suitability of five EFB resistant hazelnut cultivars, Jefferson, Yamhill, Gamma, Eta, and Theta in Kentucky plantings. Jefferson and Yamhill are main crop cultivars, whereas the other selections are mainly considered pollinizers. The cultivars Jefferson, Eta, and Theta have late blooming characteristics and may avoid late season frost and freeze events in our region. These trees were selected in the Willamette Valley in Oregon and were not specifically selected for winter hardiness in the Kentucky region; therefore, the critical winter temperatures for tree damage are not known. Additionally, it is not known if these varieties will flower early in the spring and be damaged by frost events. In 2010, plants of the five hazelnut cultivars that were produced via tissue culture by a nursery in Oregon and were shipped to Kentucky State University (KSU). Trees were grown in one gallon tree pots in the greenhouse and overwintered outside the greenhouses in a cold frame and straw. In Spring 2011, replicated trials of the five EFB resistant cultivars were established at three locations: 1) University of Kentucky (UK)-Quicksand station at Jackson, in Eastern Kentucky; 2) KSU in Frankfort, located in Central Kentucky; and 3) Western Kentucky University (WKU) in Bowling Green, located in Western Kentucky. The KSU trial was established in a randomized complete-block design with four blocks and two replicates of each cultivar per block, whereas the UK and WKU plantings had three replicate blocks. Smaller grower trials which included all five cultivars were also established at eight grower sites in Kentucky in April 2011. Irrigation was provided as needed and weeds controlled at KSU, UK, and WKU plantings. First year survival rate was excellent, at approximately 90%, and plant vigor was high for all cultivars. Winter survival, pest and disease incidence, as well as any breakdown of EFB resistance by the cultivars in the spring of 2012 will also be reported.