Effect of Indole-3-Butyric Acid (IBA) Concentrations and Cutting Lengths on the Vegetative Propagation of Dragon Fruit (Hylocereus undatus)

Abstract

Vegetative propagation through stem cuttings is important for rapid multiplication of dragon fruit (Hylocereus undatus), and establishment may be influenced by cutting length and indole-3-butyric acid (IBA) concentration. This study evaluated the interaction between three cutting lengths (20, 25, and 30 cm) and three IBA concentrations (5000, 6000, and 7000 ppm) under nursery conditions during 2023–24 and 2024–25. The treatments were arranged in a split-plot design with two replications, and shoot growth, root development, survival, root-to-shoot ratio, and related growth indices were assessed. The interaction between cutting length and IBA concentration significantly influenced the evaluated propagation traits. Among the tested combinations, 30 cm cuttings treated with 6000 ppm IBA showed the strongest overall performance. This treatment recorded the earliest first shoot initiation (31.58 days), a shoot length of 39.50 cm at 120 days after planting, 19.53 primary roots per cutting, a linear root length of 26.80 cm, and a root density of 1.97 mg/in³. It also produced the highest shoot fresh and dry weights at 120 days (140.73 and 27.40 g, respectively), together with 94.17% survival and a root-to-shoot length ratio of 0.88. The results indicate that the combination of 30 cm cuttings and 6000 ppm IBA was the most effective treatment under the experimental nursery conditions and may support efficient vegetative propagation of dragon fruit.