Association of indolebutyric acid with rhizobacteria on the viability of herbaceous minicuttings of blueberry ‘Brite Blue’

Abstract

Plant regulators used alone or associated with rhizobacteria are alternatives that maximize the rhizogenic potential of cuttings that are difficult to root, such as the blueberry. Thus, the objective of this study was to investigate if concentrations of IBA in talc, associated or not with the rhizobacteria Azospirillum brasilense and Bacillus subtilis, interfere in the viability of blueberry mini cuttings, cultivar ‘Brite Blue’. The experimental design used was entirely randomized, with four repetitions. The treatments studied, designed in a bifatorial scheme (4 × 3), were concentrations of IBA (0, 500, 1,000, and 2,000 mg L^-1), applied as talc, associated or not with A. brasilense and B. subtilis. A significant interaction was observed between the factors IBA and inoculation with rhizobacteria regarding the presence of callus. In relation to the isolated effect of inoculation, B. subtilis proved to be superior to the treatments with application of IBA alone, also presenting the highest percentage of sprouted minestems. There was an isolated effect of IBA doses on the number of roots per minicutting, survival, and rooted minicutting. It is concluded that the treatments with IBA and rhizobacteria, especially B. subtilis, favor the viability of the ‘Brite Blue’ minicuttings.