Rooting of Cercis siliquastrum cuttings influenced by cutting position on the branch and indole-butyric acid

摘要

The effects of cutting position within the source shoot and concentration of lH-indole-3-butyric acid (IBA) or its potassium salt (K-IBA) on rooting in Cercis siliquastrum were assessed. Stem cuttings were taken from terminal or basal portions of theshoots in early spring, early summer, or winter and treated with 0, 24, 48, 72 or 96 mM IBA in 50% ethanol or K-IBA in water. Terminal cuttings were also treated with a commercial rooting powder containing 0.1, 0.3 or 0.8% IBA. Rooting was unsuccessful except when cuttings were taken in the summer. Percent rooting was not significantly affected by concentration of IBA, but terminal cuttings exhibited higher rooting (43%) than basal ones (13%). Length and dry mass of roots produced per rooted cutting were significantly increased with increasing concentration of IBA Basal cuttings performed poorly irrespective of K-IBA concentration, whereas terminal cuttings treated with the higher concentrations (72 and 96 mM) exhibited greater rooting than those treated with the lower concentrations (0^48 mM). The highest rooting percentage (80%) was obtained at 72 mM K-IBA, but the shape of the response curve suggests that the optimum concentration is probably slightly above 96 mM, the highest concentration tested.The quantity of roots produced per rooted cutting was not affected by cutting position or K-IBA concentration. Treating terminal cuttings with 0.3 or 0.8% IBA powder resulted in 60% or 73% rooting, respectively. The slope of the r esponse curve suggeststhat the optimum might be above 0.8%, the highest concentration tested. The quantity of roots was not affected by IBA powder concentration.