Rooting and early shoot characteristics of Picea abies (L.) karst. cuttings originating from shoots with enforced vertical growth

Abstract

Picea abies mother‐plants from 10 serially propagated clones (14 years old, chronologically) were treated in four different ways: (1) control with intact, non‐manipulated plants; (2) like (1) but with the leader cut off; (3) intact plants but with all branches of the upper two whorls forced to grow in a vertical way; and (4) like (3) but with the leader cut off. Cuttings from four positions (cutting‐types) on the mother‐plants were collected, rooted and evaluated for rooting %, number of main roots, number of lateral roots, plagiotrophy, needle symmetry on leader and growth of leader. Treatments 3 and 4 resulted in cuttings with more plagiotropic growth but with better rooting, more lateral roots and better growth than did cuttings from treatments 1 and 2. The genotype had a significant influence on rooting. Number of main roots was significantly influenced by the genotype and the cutting‐type, but not of the mother‐plant treatment. Symmetry of needles on the leader was fairly weakly influenced by genotype and cutting‐type yet not influenced by mother‐plant treatment. Clone effect was significant for leader growth.