Substratos e ácido indol-3-butírico na produção de mudas de pitaia vermelha de polpa branca1

Abstract

Dragon fruit is a fruitful cactus originating in the tropical rainforests of South and Central America. It produces unconventional fruits that are much appreciated, with great potential for diversification of the sector. It is propagated preferentially by cutting, providing increase in the precocity and uniformity of the orchards. In order to maximize the production of seedlings, the objective was to evaluate different concentrations of indole-3-butyric acid (IBA) and three types of substrates in the production of dragon fruit seedlings ((Hylocereus undatus). The experiment was conducted in experimental design in a completely randomized block design with factorial 5 × 3 (IBA concentrations: 0, 1000, 2000, 3000, and 4000 mg L-1 × substrates: sand, sand + soil, and soil) with three reapplications. After 120 days, the following characteristics were evaluated: number of lateral cladodes, length of cladodes, fresh root biomass, dry root biomass, fresh shoot biomass, and dry shoot biomass. The results of the variables were subjected to analysis of variance and the substrates were compared by Scott-Knott and the effect of the IBA was evaluated by regression. There was a significant effect of the interaction between IBA doses and substrate types only for the variable number of cladodes. The immersion of the cuttings in solution with IBA resulted in significant differences in the phytotechnical characteristics: number and length of the cladodes, fresh root and fresh shoot biomass. The significance of the substrates occurred for the fresh and dry biomass of the roots. The range between 1776.33 and 2299 mg L-1 of IBA provides greater growth of dragon fruit seedlings. The substrate sand promotes greater rooting of the seedlings.