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Little information is available regarding vegetative propagation of the species Piper nigrum L. to generate technical recommendations for the production of seedlings on a commercial scale. The purpose of this study was to investigate the rhizogenic behavior of cultivars of this species regarding indol-3-butyric acid (IBA). The experiment was performed at a vegetation house equipped with an intermittent nebulization irrigation system. The experimental site was located in the University Center of Northern Espírito Santo (CEUNES) of the Federal University of Espírito Santo (UFES), Brazil. The experimental design consisted of randomized blocks arranged in a 3 x 5 factorial scheme: three cultivars (Bragantina, Iaçará and Guajarina) x five IBA concentrations (0; 1,500; 3,000; 4,500 and 6,000 mg kg-1), with four repetitions of 16 cuttings each. Total immersion of the cuttings in IBA is recommended for the Iaçará and Guajarina cultivars, and immersion of only the basal region is recommended for cv. Bragantina. The recommended IBA concentration for these cultivars is 4,000 mg kg-1.

The tissue culture can contribute to the propagation of several economic species, such as the bromeliads. This research aimed at evaluating the auxins type and concentration in the in vitro and ex vitro rhizogenesis of Neoregelia concentrica bromeliad. N. concentrica shoots were induced in a growth medium with 15.0 µM of 6-benzylaminopurine, for 80 days, followed by sub-cultivation in phytoregulator-free medium, for 45 days. In the in vitro rhizogenesis, the shoots grew in a medium supplemented with indole-3-butyric acid (IBA) or naphthalene-acetic acid (NAA), at the concentrations of 0.0 µM, 1.0 µM, 2.0 µM, 3.0 µM and 4.0 µM. In the ex vitro rhizogenesis, the bases of shoots were immersed, for 60 minutes, in IBA or NAA solutions, at the concentrations of 0.0 µM, 5.0 µM, 10.0 µM and 15.0 µM. After immersion, the shoots were planted in plastic trays with vermiculite. At the end of each rhizogenesis method, the phytotechnical parameters analysis was carried out. For the in vitro rhizogenesis, a higher number of roots were observed when the shoots were cultivated in concentrations higher than 1.0 µM of NAA, when compared to the IBA. However, the rooting rate differed only at 30 days after the in vitro growth, with a higher root induction in the shoots grown with NAA. At 60 days, the rooting rate was higher than 90% and statistically similar in all treatments. In the ex vitro rhizogenesis, a better formation of the rooting system was observed when 5.0 µM of IBA was applied, with higher rooting averages and number of roots.