Enhancing the rooting of Canada yew stem cuttings with IBA treatments

Studies on rooting stem cuttings of Taxus canadensis Marsh., a shrub containing an anti-cancer chemical, paclitaxel, are reported. Dipping the stem base in a powder (0.8% IBA) improved neither the rooting nor the growth of adventitious roots (compared with controls) regardless of predetermined clone rooting abilities. Quick dips in concentrated IBA (0, 0.5, 1.0 1.5 and 2.0% in 50% ethanol) stimulated rooting, with 0.5% and 1.0% producing the best survival, while the 2% dip gave the best root growth. Clone ortets classified as good or recalcitrant (difficult to root) did not differ significantly in their Ingestad nutrient ratios and in foliar macronutrient concentrations, except for Ca, which had a greater concentration and larger ratio in the recalcitrant category. Concentrations of N and P were positively correlated with the rooting percentage, whereas K and Mg concentrations were negatively correlated.