Partial “Rejuvenation” of 20-Year-Old Sitka Spruce by Lower Crown Pruning
Once trees have attained an age at which elite individuals can reliably be selected they are usually too old to be vegetatively propagated successfully, because of problems related to plant aging (Bonga, 1987). Close proximity to a root system or to the tree base has frequently been associated with the maintenance of juvenility. For example, hedging (Libby and Hood, 1976) or serial propagation of cuttings (St. Clair, Kleinschmit and Svolba, 1985) has been used to retain juvenile rooting potential, whilst pruning (Copes, 1983) or production of stump sprouts (Boulay, 1979) has been used to improve the rooting potential or cultural properties of tissues.
KeywordsGrowth Habit Stem Cutting Mother Tree Rooted Cutting Plant Maturation
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