`Willamette' Hazelnut

Abstract

Willamette, released in 1990 for the blanched kernel market, resulted from a cross between Montebello and Compton (Barcelona X Daviana) made in 1973. Trees of Willamette are vigorous, upright and spreading, and similar in size and growth habit to Barcelona. Nuts are borne in clusters of 1-5 and on the ground are ready for mechanical harvesting 1 week later than Barcelona. Willamette has the incompatibility alleles S 1 and S 3. Negret is an adequate pollenizer but Tonda di Giffoni is the recommended pollenizer. Nut yields of Willamette are slightly higher than those of Barcelona in trials during 1985-90 (12.0 vs. 10.9 kg/tree). Nuts of Willamette are smaller (2.9 vs. 3.8 g) and have thinner shells (50 vs. 44% kernel) than those of Barcelona and are described as medium large. Shells are less pubescent than those of Barcelona, are a rich chestnut brown and very attractive. Pellicle removal rates are similar to those of Montebello and Tonda Gentile delle Langhe and kernel flavour and texture have been rated as very good. Brown stain disorder is rare in Willamette. Yield of good kernels is 50% higher for Willamette than for Barcelona. Willamette appears to have a moderate level of resistance to Anisogramma anomala.