Effect of Indole−3-butyric acid (IBA) concentrations and rooting media on the adventitious rooting and seedling vigor of Mango (Mangifera indica L.) cuttings

A controlled experiment was conducted at Arba Minch to evaluate the effects of Indole−3-Butyric Acid (IBA) concentrations (0, 4000, and 5000 ppm) and different rooting media [Soil+FYM+Sand (3:2:1), 100% Poultry Manure, and 100% Cotton Manure] on the rooting and growth of mango cuttings. The experiment followed a Completely Randomized Design with four replications. Data were collected on rooting percentage, root architecture, and vegetative growth parameters over a 120-day period. Analysis of variance revealed significant interaction effects between IBA levels and rooting media (P < 0.05). The combination of 4000 ppm IBA and Soil+FYM+Sand (3:2:1) yielded superior performance across all metrics. The highest rooting percentage reached 92.05%, whereas the rooting percentages for the control (0 ppm) treatment across media M1, M2, and M3 were 59.21%, 53.09%, and 55.80%, respectively. Cuttings in the 4000 ppm/Soil-Mix group also produced the highest number of roots (18.75) and the greatest root dry weight (6.14 g). Furthermore, seedling vigor was significantly enhanced, with plant height reaching 36.16 cm and leaf count averaging 15.24 per cutting (P < 0.05). Conversely, 100% cotton manure and untreated cuttings exhibited the lowest root-to-shoot ratios and biomass accumulation. The study demonstrates that 4000 ppm IBA paired with a balanced Soil+FYM+Sand (3:2:1) substrate provides the optimal physiological and physical environment for mango propagation. It is recommended that commercial nurseries adopt 4000 ppm IBA and the Soil+FYM+Sand (3:2:1) medium to ensure high survival rates and robust seedling growth.