Effects of Different Concentrations of Exogenous Auxins (IAA, IBA, and NAA) on Growth and Rooting Ability of Philodendron hederaceum var. oxycardium (Schott) Croat Stem Cuttings

Background and objective: This study aimed to investigate the effects of different types and concentrations of exogenousauxins on growth and rooting ability of Philodendron hederaceum var. oxycardium stem cuttings. Methods: Auxins used included indole acetic acid (IAA) at concentrations of 80, 160, and 320 mg·L-1, and 3-indolebutyricacid (IBA) and 1-naphthylacetic acid (NAA) at concentrations of 250, 500, and 1000 mg·L-1, respectively. Results: The application of auxins significantly improved the mean survival rate to 97.4%, compared to 91.4% in the control. The mean rooting rate also increased with auxin treatments, to 94.5% compared to 85.4% in the control. Additionally, shootlength, width, and both fresh and dry weights peaked at an IAA concentration of 320 mg·L-1, while leaf length and widthwere optimal at an IAA concentration of 160 mg·L-1. In contrast, the best results for root length and biomass, both freshand dry weights, were observed with an IBA concentration of 250 mg·L-1. The Commission Internationale de l'EclairageLab (CIELAB) color space analysis showed that the control had higher L*(lightness) and b*(yellowness) values, indicatinga lower ornamental value. Conclusion: The findings confirm that auxins effectively enhance the stem-cutting propagation of P. hederaceum var. oxycardium, regardless of type and concentration. For optimal shoot growth, an IAA concentration of 320 mg·L-1 isrecommended, while an IBA concentration of 250 mg·L-1 is most effective for root growth.