New hazelnut cultivars from Oregon State University

D.C. Smith, R.L. McCluskey, S.A. Mehlenbacher
The hazelnut breeding program at Oregon State University (OSU) is developing new cultivars with high nut yield, few defects, and good kernel quality. Every year, approximately 4500 seedlings are planted and evaluated for seven years. The very best of these seedlings are put through a second period of testing in replicated yield trials to determine their potential as cultivars. The fungal disease eastern filbert blight (EFB) is now widespread in the Willamette Valley, so current trials include only EFB-resistant selections. In this paper, we summarize data for three recent releases. ‘York’ (OSU 878.048) is a widely compatible mid-season pollinizer with nuts and kernels that blend well with other recent OSU releases. ‘Wepster’ (OSU 894.030) and ‘McDonald’ (OSU 880.027) were released as main crop cultivars. Trees of ‘Wepster’, ‘McDonald’, and ‘York’ have rounded, moderately upright growth habits, and mature nuts 7-14 days before ‘Barcelona’. ‘Wepster’ nuts and kernels are small, similar in size to ‘Yamhill’, and have very few defects. The percent kernel of ‘Wepster’ is only 44% on average, but total nut yields are very high. ‘McDonald’ nuts are medium to small in size and are suitable for the kernel market. Nuts and kernels of ‘York’ are of good quality, but trees yield less than what is desirable for a main cultivar. ‘York’ has incompatibility alleles S2 and S21, but only the uncommon S21 is expressed in the pollen. It is an excellent mid-season pollinizer, producing large quantities of highly viable pollen over a period of several weeks, and is compatible on most other genotypes. ‘Wepster’, ‘McDonald’ and ‘York’ are fully cross-compatible and are recommended to be planted together. All three are protected with US Plant Patents.
Smith, D.C., McCluskey, R.L. and Mehlenbacher, S.A. (2018). New hazelnut cultivars from Oregon State University. Acta Hortic. 1226, 47-52
DOI: 10.17660/ActaHortic.2018.1226.6
Corylus avellana, hazelnut breeding, eastern filbert blight, pollinizer

Acta Horticulturae