Development of an efficient method for mini kiwi (Actinidia arguta Planch.) propagation in georgia using hardwood cuttings

Mini kiwi (Actinidia arguta) is an emerging high-value minor fruit crop with increasing global prominence and market demand, However, its commercial propagation remains a significant challenge due to the complexity of vegetative reproduction. This study aimed to establish a scientifically validated, efficient protocol for propagating mini kiwi via hardwood cuttings under Georgian agroclimatic conditions. The research was conducted between 2021 and 2023 at the LEPL Scientific-Research Center of Agriculture (SRCA), located in Jighaura Village, Mtskheta-Mtianeti, Georgia. The study systematically evaluated the influence of different rooting hormone treatments - including indole-3-butyric acid (IBA; Dushefa-Biochemie) and powdered Kornevin (0.5% IBA) - alongside substrate composition and controlled environmental parameters on rooting success, survival rate, and shoot emergence in mini kiwi cuttings. Dormant hardwood cuttings were treated with five IBA concentrations (Control - water, 1,000 ppm, 2,000 ppm, 3,000 ppm, and 0.5% Kornevin powder) and planted into four distinct substrates: perlite with peat moss, coco coir with sand, vermiculite with peat moss, and commercial potting mix. Environmental conditions were optimized throughout the rooting period, maintaining a soil temperature of 18–22°C, relative humidity of 80–90%, a 12-hour photoperiod, and intermittent mist irrigation. The results demonstrated that IBA treatment significantly enhanced rooting percentage, root length, and survival rate compared to the untreated control. Among the tested concentrations, 2000 ppm IBA combined with a perlite-peat moss substrate yielded the highest rooting performance - achieving a rooting percentage of 72.7%, mean root length of 7.1 cm, and survival rate of 87.7 %. Analysis of variance (ANOVA) confirmed statistically significant differences among treatments (p < 0.001), while post-hoc comparisons identified the perlite–peat moss mixture as the most effective substrate for root development. Notably, shoot emergence was also maximized under these optimized conditions. These findings align with international studies and provide the first comprehensive, locally validated propagation protocol for mini kiwi in Georgia. In conclusion, the application of 2000 ppm IBA and perlite + peat moss substrate is recommended for commercial-scale propagation of mini kiwi via hardwood cuttings in Georgia. This protocol will enable nurseries and growers to efficiently produce high-quality, genetically uniform planting material, supporting the expansion and sustainability of mini kiwi cultivation in the region. Further research should investigate seasonal and genotype-specific responses to optimize propagation strategies.