Date of sowing and nursery growth of provenances of Pseudotsuga menziesii given two fertilizer regimes.
Seed collected from natural stands of P. menziesii growing at (a) 250, (b) 520 and (c) 880 m alt. in Oregon, and from a cross between trees in (a) and (b), were sown between April and July 1974 and either fertilized with NPK or untreated; all plots were fertilized in 1975. Early sowing significantly increased stem ht. and diam., advanced budset and altered the elongation period (EL), extending it in 1974 and shortening it in 1975. Application of NPK increased EL for seeds sown early, and increased ht. and diam. of all seedlings. There were significant differences between provenances for stem diam., and for dates of budset and budflush. Interactions between provenances and dates of sowing were significant for dates of budset and budflush, and for stem form, ht. and diam. It is concluded that comparisons of young material from different provenances should take account of the effects of cultural conditions, particularly those which alter EL. From author's summary.