Douglas-fir (Pseudotsuga menziesii) is a commercially and ecologically important tree species native to western North America. The foliar pathogens Phaeocryptopus gaeumannii, the causal agent of Swiss Needle Cast, and Rhabdocline species, the causal agents of Rhabdocline needle cast, are two important pathogens specific to Douglas-fir. These pathogens are highly influenced...
The main objective of this study was to evaluate the interaction between
herbaceous competition, fertility, and seed source on Douglas-fir survival and
growth. A secondary objective was to evaluate the effect of these various factors
on the production of lammas shoots and the selectivity of deer browse. Finally,
the role...
The effects of clonal variability, crown position of cones, and top-pruning of ramets to reduce height growth, on 1) the proportion of viable self-fertilized progeny (s) and 2) the proportion of filled seeds (PF), were investigated in a 20 year-old Douglas-fir (Pseudotsuga menziesii [Mirb.1 Franco) seed orchard. Cones were collected...