Possibilities of influencing the rooting quality of Norway spruce (Picea abies [L.] Karst.) cuttings

The influence of the date of cutting collection and cutting position in the crown on rooting quality was evaluated in cuttings taken from seven-year ortets. The evaluation of various dates of cutting collection in spring demonstrated a possibility of successful propagation by cuttings during a relatively long period from full bud dormancy to flushing onset. The relationship between the development of aboveground parts (flushing, shoot and bud formation) and rooting quality was not established. The exposure of cuttings in the crown of parent tree with respect to the cardinal points did not influence rooting percentage and quality. A somewhat higher rooting ability was observed in cuttings from lower parts of the crown in comparison with cuttings taken from the highest whorls. Differences were more perceivable in generally weak-rooting clones. The comparison of rooting quality in cuttings from seven- and eight-year mother plantations with cuttings from a sixteen-year mother plantation confirmed that not only the rooting of cuttings collected from older mother plantations is weaker but also their growth is slower and their plagiotropic growth continues for a longer time.