Effects of Cone-Picking Date on Douglas-Fir Seed Quality

Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) cones were picked on four dates between July 23 and September 4, 1958, and stored up to 14 weeks before seed extraction. Cones picked July 23 were not mature but ripened after 2 weeks in storage; germination tests were normal but X-ray examination showed that embryo and endosperm development was incomplete. Cones picked later produced mature seeds by all tests, with maturity attained when the reducing sugar levels dropped to 14 mg/g. Early picking had no adverse effect on seed extraction, although seedlings from early picked seeds weighed less than seedlings from more mature seeds. No loss in viability occurred in either early picked or mature seeds after storage for 8 years.