Stratification of Seeds of Western and Utah Juniper

Washington D.C.

1988

S. 1059-1066

4 Tab., 19 Lit. Ang.

Bandaufführung

16082

Seeds of western juniper (Juniperus occidentalis subsp. occidentalis Hook.) and Utah juniper (J. osteosperma (Torr.) Little) are highly dormant when freshly harvested. Cool-moist stratification at 5C for 14 weeks invermiculite enhanced subsequent emergence of seedlings of both species, but to tal emergence was still low. The year of seed production greatly influences theviability of seedlots. Dry storage for 1 to 4 years at room temperatures did n ot enhance germination. Outdoor stratification, overwinter, in sand, enhances subsequent emergence depending on the environment of the stratification site. The year of seed production also interacts with outdoor situations. Repeat stratification treatments, interrupted by 8-week continuously wet-emergence-assay periods in the greenhouse and dry storage during the summer were cumulative for increased seed germination of both species. Interrupted treatments were more effective than continous stratification in excess of the optimum duration to enhance germination. Stratification in aqueous solutions with near saturation of the solution with oxygen increased subsequent emergence of seedlings of westernand Utah juniper to about 50%. Similar treatments using aqueous solutions of 0.289 m mol L-1 gibberelin (GA3) enhanced subsequent emergence of seedlings of western juniper to better than 80%.