Cooperative Second-Cycle Breeding and Testing of Coastal Douglas-fir in the US Pacific Northwest: Strategy, Implementation, and Operational Aspects

Abstract

Abstract The second cycle of cooperative breeding and testing of coastal Douglas-fir in western Oregon and Washington was started around 1992. By 2020 the bulk of testing is nearing completion, while the latest program in southern Oregon and NW California is scheduled to run through 2035. A total of 109 first-generation programs were consolidated into nine second- cycle breeding and testing cooperatives (with 15 testing zones); 136 tests are planned, of which 120 have already been established. Between five and eight tests are established per trial series. Trials established to date have contained from 50 to 283 full-sib crosses. In total, the Douglas-fir breeding effort will be comprised of over 2,900 crosses, of which 2,500 have already been established in the field. A total of about 349,000 test trees are to be planted, with over 310,000 already planted. Tests typically get three main measurements when the trees are 3 (or 4), 7 and 12 years old from seed. (1) Age-3 or 4: progression of budburst, on a 1 to 5 rating score, when roughly 50 % of the seedlings have broken bud, on one or two sites per trial series. (2) Age-7: height (height pole), dbh, stem sinuosity in the second internode from the top, number of incidences of stem forking, number of incidences of ramicorn branching and (3) Age-12: height (vertex), dbh, stem sinuosity in the second internode from the top, number of incidences of stem forking, number of incidences of ramicorn branching, second flushing yes\no in current year, and wood acoustic velocity (in some trial series).