Comparative evaluation of IBA and NAA effects on rhizogenesis and shoot morphogenesis in rose stem cuttings

This study was conducted atthe Floriculture Nursery, Faculty ofAgriculture and Natural Resources, Aswan University, Aswan, Egypt, during the 2021/2022 and 2022/2023 growing seasons. The experiment aimed toevaluate the effects oftwo plant growth regulators (PGRs), indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA), onthe root and shoot development ofrose, aspecies known for its poor rooting ability. Asplit-plot arrangement within arandomised complete block design was used, with PGR type assigned tothe main plots and concentrations (control, 500, 1 000, 1 500, and 2 000 ppm) allocated tothe sub-plots. Both IBA and NAA significantly improved plant height, root length, and potassium content. The application of500 ppm IBA and 1 000 ppm ofNAA produced the greatest increases inrooting percentage, number ofleaves and branches, shoot and root fresh and dry weights, and phosphorus content. Higher concentrations (1 500 and 2 000 ppm) reduced the time required for leaf sprouting and increased stem diameter aswell asnitrogen content. Overall, concentrations between 500 and 1 500 ppm enhanced both shoot and root growth. However, soaking stem cuttings ina2 000 ppm IBA solution for 30 minutes was the most effective for promoting root formation and improving overall plant growth.