Seed maturity in white fir and red fir

Abstract

White fir and red fir seed collected over a 2-month period in northern California was tested for germination of fresh and stratified seed. Ratio of embryo length to embryo cavity length was found to be the most useful index of seed maturity for white and red fir. Cone specific gravity also was correlated with nearly all measures of seed germination. Data suggest that red fir cones should be collected as close to beginning of seed fall as possible. White fir cones should be collected within 3½ weeks of seed fall. White fir cones collected 4 weeks before seed fall can be artificially ripened, however. These cones yielded seed which germinated as completely and speedily as stratified seed from mature cones.

Citation

Oliver, William W. 1974. Seed maturity in white fir and red fir. Res. Paper PSW-RP-99. Berkeley, CA: Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture; 12 p