Stratification Period and Germination of Douglas-Fir Seed from Oregon SeedOrchards: Two Case Studies

摘要

Effect of stratification period (S) and incubation temperature (T) on germinationbehavior were tested by using two groups of Douglas-fir orchard seedlots that had given low germination percentages in standard tests. Seedlots with poor or slow germination in standard tests germinated completely, quickly, and uniformly at 15 and 25 C if stratified for 12 weeks. Six-week stratification was insufficient for complete germination of some seedlots at 15 C incubation. Method of cone drying, year of collection, and orchard block influenced germination behavior.