Productivity of polyclonal minigarden and rooting of Handroanthus heptaphyllus Mattos minicuttings

Resumo

Aiming the improvement of the quality of techniques related to the growth of “ipê-roxo” cuttings, this study had as objective to evaluate the productivity of Handroanthus heptaphyllus Mattos ministumps and the rooting capacity of the minicuttings in successive collections in the presence and absence of exogenous auxin. Seedlings were grown in 280 cm3 tubes with selected different sources of seeds. At 141 days after the sowing, seedlings were pruned at 8 cm from the collar with the goal to establish the minigarden. The productivity of ministumps over successive collections as well as the need to apply indol-3-butiric acid on the roots of the minicuttings were evaluated. Eight collects of minicuttings were carried out, at three, five, six, seven, eight, nine, 10 and 11 months after the pruning. In each of those cycles the number of minicuttings were quantified per mini-stump. Before their staking in 180 cm 3 tubes, half of the minicuttings from each cycle were treated with 8000 mg L-1 of Indole-3-Butiric Acid (IBA) (2 seconds). The ministumps tolerated the pruning (with 100% survival); over 70% of the ministumps produced minicuttings along all the time in each collection cycle. A cyclical behavior in the minigarden was observed with higher productivities of the ministumps at 8 and 11 months after pruning of seedlings. The use of IBA stimulated more robust root systems of the cuttings, although this was not a condition for rooting.