Interactions Among Rooting Substrate, Phenological Stage of Cuttings, and Auxin Concentration Impact in In Vivo Rooting of Cotinus obovatus

Abstract

A study was conducted to determine the effects of substrate, phenological stage of cuttings, and auxin concentrations on the rooting of Texas smoke tree (Cotinus obovatus Raf.). Softwood, semi-hardwood, and hardwood cuttings were treated with either a 0, 5,000, 10,000, or 15,000 mg·L-1 (ppm) potassium salts of indolebutyric acid (K-IBA) and placed in either 50% peat: 50% perlite or 100% perlite rooting substrates. Cuttings were places under an intermittent mist system in a greenhouse for 8 weeks. Softwood cuttings rooted in both substrates, but the 50% peat: 50% perlite substrate produced better-quality rooted only in the 100% perlite substrate. In 100% perlite substrate, the optimal concentration for semi-hardwood cuttings was ≈12000 mg·L-1 (ppm) K-IBA, while hardwood rooting was maximized at 15000 mg·L-1 (ppm) K-IBA or more.