Effect of different hormone doses on propagation by softwood cutting of Magnolia kobus

Magnolia kobus native to Japan is a small tree-shaped plant from the Magnoliaceae family, which sheds its leaves in winter, about 10 m tall and has a round form. It is one of the plants preferred in Landscape Architecture planting designs with its form, aromatic leaves, abundantly blooming pinkish-white flowers and fruit beauty. It is very effective in groups or solitary use. It is resistant to urban climate and cold. In this study, our aim is to encourage the use of this plant, which is valuable with its aesthetic properties, by propagation with cutting production in the urban landscape. Within the scope of the study, the production technique with mild cutting, which is one of the vegetative production techniques, was used. In this current study, the effect of different hormone applications on the rooting success of softwood cuttings of Magnolia kobus was investigated. 0 (control), 3000, 5000 and 8000 ppm doses of hormones IBA (Indol-3-butyric acid), IAA (Indole-3-acetic acid) and NAA (Naphthalene acetic acid) were applied to the cuttings. Cuttings were planted in perlite medium under greenhouse conditions (20±2 ºC air temperature, 25±2 ºC rooting table lower temperature, 70±2% humidity). After about 4 months, the cuttings were removed and the rooting rate (%) and root lengths (cm) were determined. As a result of the study, the highest rooting percentage (60%) was seen in cuttings treated with 8000 ppm dose of IBA hormone. The highest root length values in cuttings were determined in cuttings treated with IAA 3000 ppm and 5000 ppm doses. According to the results of analysis of variance, it was determined that hormone applications had a significant effect on rooting (P: 0.000 ˂ 0.05). This study was supported by Karadeniz Technical University Scientific Research Projects Unit (Project no: 9733).