Effects of Rootstock Source on the Size, Cone Production, and Compatibility of Douglas-Fir Grafts

Abstract

Abstract Scions of coastal Douglas-fir (Pseudotsuga menziesii) were grafted on rootstock from coastal, northern interior and southern interior origin. Data on ramet size, cone production, and graft compatibility were collected. Twelve years after grafting significant differences for most crown and stem traits were found among the rootstock sources, with coastal rootstock resulting in the fastest scion growth. Northern interior rootstock sources produced larger grafts than southern interior rootstock. Significant graft union appearance and cone production differences were not detected, but coastal sources consistently had higher graft compatibility and healthier unions. It is concluded that, for coastal Douglas-fir, the use of a vigorous coastal rootstock source that promotes fast growth in the scion, and has high graft compatibility potential, is the most desirable for coastal locations. This will result in fewer losses due to graft incompatibility, faster crown development, more options for crown management and increased cone production potential. West. J. Appl. For. 7(3):73-77.