EFFECT OF TREE FLOWERING AND CROWN POSITION ON ROOTING SUCCESS OF CUTTINGS FROM 9-YEAR-OLD BLACK SPRUCE OF SEEDLING ORIGIN

Cuttings were taken at different levels in the crown of both flower-be aring and sexually immature 9-year-old black spruce seedlings (Picea m ariana (Mill.) B.S.P.). We obtained satisfactory rooting success, desp ite the relatively old age of the trees. The rooting percentage of the cuttings taken from the lower third of the crown was significantly hi gher (p < 0.01) than that of the cuttings originating from the middle and top thirds of the crown (53%, 36%, and 29%, respectively). Cutting s from the upper portion of the crown showed persistent signs of advan ced maturation, while those from the bottom of the crown regained an a lmost juvenile appearance after rooting. Surprisingly, the cuttings ta ken on flower-bearing trees rooted better (p < 0.10) than those taken on sexually immature trees (48% vs. 30%). Large and significant differ ences were also recorded between individuals of both groups. No signif icant interaction was found between sexual maturity and crown position of the cuttings for rooting percentage. The effects of maturation on the rate of rooting and the relevance of replacing grafting by rooting for certain purposes are discussed.