Enhancing Cutting Propagation in (Photinia x fraseri) Plant Through the Synergistic Effect of IBA, Glycerol, and Growing Media Mixture.

The experiment was performed on the red tip photinia plant inside a greenhouse at the College of Agricultural Engineering Sciences, University of Duhok, during the growing season of 2024. To investigate the effect of two growth mixtures; peatmoss + sand + soil and peatmoss + sand + clay, three levels (0, 3500, and 7000 mg. L-1) of indole-3-butyric acid (IBA), and four concentrations (0, 5, 15, and 30%) of glycerol solutions on cutting propagation of the (Photinia x fraseri) plant. The results show that peatmoss + sand + soil significantly enhanced branch number and chlorophyll content, while peatmoss + sand + clay significantly increased leaf dry weight. However, IBA at 7000 mg. L-1 significantly recorded maximum root number and root length, whereas the control and 3500 mg. L-1 of IBA significantly increased leaf fresh weight. The influence of glycerol at 15% significantly induced most study parameters such as rooting percentage, root number, root fresh weight, root dry weight, leaf fresh weight, and leaf dry weight. Despite that, photinia cutting at 5% or without glycerol applications significantly improved rooting percentage and leaf number. The interaction among peatmoss + sand + soil, 7000 mg.L-1 IBA, and 15% glycerol significantly enhanced rooting percentage and root number. Furthermore, the combination of peatmoss + sand + soil, 7000 mg.L-1 IBA and 5% glycerol significantly improved chlorophyll content and root fresh weight. Still, peatmoss + sand + soil, 3500 mg.L-1 IBA, and 5% or 30% glycerol significantly recorded higher leaf and branch numbers, respectively.