Rocky Mountain Juniper Study: Preliminary Results
Rocky Mountain juniper (Jun perus scopulorum Sarg.) seed are hard to germinate in the nursery, containers, or laboratory because they have multiple dormancies. The seedcoat and prophylactic sheath surrounding the embryo impede water absorption. The embryo's epicotyl is not dormant; only the hypocotyl displays dormancy and requires cold stratification (Djavanshir and Fechner 1976). Stratification of dormant seed involves three stages (Nikolaeva 1969). During the first stage an initial vigorous swelling of seed take place. Following full imbibition the second stage ensues. Enzymatic activity and hydrolysis of proteins and fats begins. Products from the hydrolytic process prompt the beginning of embryo growth, which constitutes the third stage. Growth activation occurs during stratification in two periods. Mitoses occurs at the end of warm stratification when seed open; whereas, the second activation of growth happens at the end of cold stratification, prior to germination. This leads to a perennial nursery problem because germination cannot always be predicted. Weather patterns are not identical in every nursery that grows Rocky Mountain juniper. Southernmost nurseries may not receive enough cold weather to provide a sufficient cold stratification period for seed germination.
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Author(s): Jill Barbour
Publication: National Nursery Proceedings - 1999
Event:
Northeastern and the Western Forest and Conservation Nursery Associations Meeting
1999 - Ames, IA
