Optimisation of Propagation Structures and Indole-3-Butyric Acid Concentrations for Large-Scale Clonal Multiplication of Hibiscus rosa-sinensis Culture AccHR1

Abstract

Effective vegetative propagation is essential for rapid multiplication and maintenance of genetic fidelity in ornamental crops such as Hibiscus rosa-sinensis. The success of clonal propagation through stem cuttings is strongly influenced by the propagation environment and the application of rooting hormones. The present investigation was conducted to standardise suitable propagation structures and identify an effective concentration of indole-3-butyric acid (IBA) for improving rooting and establishment of Hibiscus rosa-sinensis culture AccHR1 under protected conditions. The study was carried out during 2022-2023 at the Department of Floriculture and Landscape Architecture, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India. Semi-hardwood cuttings of H. rosa-sinensis culture AccHR1 were treated with IBA at 1000, 2000, 3000 and 4000 ppm and maintained under three propagation structures: mist chamber, shade net and poly tunnel. The experiment was laid out in a factorial randomised block design comprising eighteen treatments with three replications. Significant treatment effects were observed for all measured traits. The earliest sprouting was recorded in cuttings treated with 3000 ppm IBA under mist chamber conditions. However, superior vegetative growth and rooting characteristics were recorded in cuttings treated with 4000 ppm IBA under mist chamber conditions. This treatment combination produced greater plant height, higher leaf production, larger leaf area, improved root traits and better establishment of cuttings. Based on these findings, treatment of semi-hardwood cuttings with 4000 ppm IBA under mist chamber conditions may be recommended as an effective propagation strategy for rapid rooting and large-scale clonal multiplication of H. rosa-sinensis culture AccHR1.