Vegetative rescue and ex vitro system production of Tibouchina sellowiana clonal plants by cutting and mini-cutting

ABSTRACT: We aimed to evaluate the rooting potential of Tibouchina sellowiana through the experiments: I - Cuttings from current-year shoots and epicormic shoots were submitted to IBA concentrations: 0, 500, 1000, 1500 and 2000mg L-1, in a factorial arrangement 2 x 5 (two types of cuttings x five IBA concentrations), with four replicates and 20 cuttings each; II - mini-stumps of Tibouchina sellowiana were submitted to successive shoots collecting during the four seasons, in a split-plot design, with five replications of ten mini-stumps per experimental unit. From the shoots of mini-stumps, mini-cuttings were produced, which were initially kept in greenhouse and later transferred to full sun, in a 4 x 5 factorial arrangement (four seasons x five collections per season), with four replicates of 12 mini-cuttings. Superiority of epicormic shoots cuttings was reported when compared to the current-year shoots, which showed the highest rooting and leaves maintenance (42.50% and 55.00%, respectively), eliminating the use of IBA. High survival of mini-stumps (over 80%) and the mini-cuttings production (170mini-cuttings m-2 month-1) in clonal mini-garden and the mini-cuttings survival (above 80%) in the greenhouse demonstrated the technical feasibility, with summer as the most appropriate time to collect mini-cuttings.