EX VITRO SYSTEM FOR Acer palmatum PLANTS PROPAGATION BY MINI-CUTTINGS TECHNIQUE

This study presents an efficient system with high productivity and quality for Acer palmatum propagation. We evaluated the efficiency of mini-cuttings technique, management of mini-stumps, production of shoots, rooting and root vigor of mini-cuttings on two seasons. The mini-stumps were planted in pots of two liters, put up in two environments (full sunlight area and shade house) and submitted to weekly fertigation. Over six collections, we evaluated the survival and productivity of clonal mini-garden (Experiment I). From these, we performed two experiments with mini-cuttings: Experiment II - mini-cuttings originated from two environments, with 8 +/- 1 cm, put to root in two seasons (Spring and Summer); Experiment III -mini-cuttings originated from full sunlight area, with 4 +/- 1, 6 +/- 1, 8 +/- 1, 10 +/- 1 cm, put to root in Summer. The mini-cuttings planting was made in plastic tubes of 55 cm 3, filled with fine vermiculite and carbonized rice hulls (1: 1 v/v), in a greenhouse with intermittent irrigation system. The high rooting (95.0%), mini-stumps survival (100%) and mini-cuttings production (217.5 mini-cuttings m(-2) month(-1)) in clonal mini-garden conducted in full sunlight area shown the technique viability for the species. Mini-cuttings of 8 +/- 1 cm favored rooting (96.3%). The mini-cuttings technique is viable for Acer palmatum propagation.