Effects of Tree Spacing and Height Reduction on Cone Production in Two Douglas-Fir Seed Orchards

Abstract

Abstract Two treatments involving tree spacings (12 and 24 ft) within rows spaced 24 ft apart and height control (topped or not topped at 20 ft) were evaluated in 17- and 22-yr-old coast Douglas-fir (Pseudotsuga menziesii var. menziesii) seed orchards. Treatment differences for cone production were not significant because of the large tree-to-tree variation in cone production and, at one orchard, the confounding of location with treatment. Cone production in 1990 averaged slightly more than 2 bushels per tree (range 0 to 11.7 bushels). Average production per 96 linear ft of orchard row was 14.8 bushels. West. J. Appl. For. 9(1):5-7.