Evaluating IBA and NAA for improved rooting in pot mum cultivation (Dendranthema grandiflora Tzvelev.)

The present investigation was conducted from November 2023 to August 2024 under polyhouse conditions at the Department of Floriculture and Landscaping, College of Horticulture, Bengaluru, to evaluate the influence of plant growth regulators on the rooting of cuttings. The experiment was laid out in a Factorial Completely Randomized Design (FCRD) comprising seven treatments with different concentrations of Indole-3-butyric acid (IBA) and Naphthaleneacetic acid (NAA), across five varieties, with three replications. Significant differences were observed among the treatments and varieties for all rooting parameters studied. Early root initiation (7.33 days) was recorded in cuttings of the variety Camargo treated with IBA at 400 ppm (T₃V₅), which was statistically on par with NAA at 200 ppm (T₆V₅). The maximum number of roots (49.67) was also obtained in Camargo under IBA 400 ppm, indicating the effectiveness of this concentration in stimulating root proliferation. With respect to root length, the highest value (4.98 cm) was observed in Camargo cuttings treated with NAA at 250 ppm (T₇V₅). Further, the maximum percentage of rooting (98.10%) was achieved in T₃V₄, signifying varietal differences in response to treatments. The findings clearly demonstrate that both IBA and NAA significantly enhanced rooting attributes, though the magnitude of response varied with variety and concentration. Based on the results, the study recommended the application of IBA at 400 mg L⁻¹ or NAA at 200 mg L⁻¹ for achieving superior root initiation, higher root number, and enhanced rooting percentage in cuttings, thereby improving propagation efficiency in pot mums.