How to identify bud initiation and count needle primordia in first-year spruce seedlings

Bud initiation and subsequent bud development are key steps in the nursery production of first-year temperate spruce seedlings for reforestation. An understanding of the bud initiation and development processes and monitoring methods are of vital importance to both tree seedling nursery workers and foresters. A review of bud morphology and the bud development process is given for spruce seedlings. The equipment required and techniques used in the determination of bud initiation, and estimation of the number of needle primordia are presented. When properly applied, the examination of spruce buds forms a cornerstone for successful nursery management using extended greenhouse culture. Key words: bud initiation, bud morphology, bud dissection, black spruce, Picea mariana, needle primordia, nursery management