PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Dragon fruit (Hylocereus costaricensis) is a high-value, drought-tolerant cactus fruit whose commercial expansion in India is presently constrained by the poor and inconsistent availability of quality planting material. Since the crop is propagated almost entirely through stem cuttings, a field-cum-nursery experiment was conducted during 2025–26 at the Department of Fruit Science, College of Horticulture, C.S. Azad University of Agriculture and Technology, Kanpur (U.P.), to determine a reliable auxin schedule for rooting. Thirteen treatments, comprising three levels each of Indole-3-butyric acid (IBA at 1000, 2000 and 3000 ppm) and Naphthalene acetic acid (NAA at 100, 200 and 300 ppm), six IBA × NAA combinations, and an untreated control, were laid out in a Randomised Block Design with three replications. Cuttings treated with IBA at 3000 ppm consistently gave the quickest and most vigorous response, with root initiation in 16.53 days and sprouting in 9.39 days, compared with 22.90 and 17.33 days, respectively, in the control. The same treatment produced the highest rooting (53.20% at 60 days after planting), the longest roots (20.13 cm) and greatest root number (40.95) at 90 days, the tallest shoots (14.20 cm), and the best survival of rooted cuttings (90.12%), and remained statistically on par with IBA at 2000 and 1000 ppm across most parameters. NAA alone was distinctly less effective than IBA, and the IBA + NAA combinations did not improve upon IBA used alone. On the basis of these results, a quick-dip treatment with IBA at 3000 ppm (or, where cost is a constraint, 1000–2000 ppm) can be recommended for the commercial nursery propagation of dragon fruit through stem cuttings.