Propagule and indole-butyric acid in mini-cutting rooting of Acacia mearnsii

Acacia mearnsii (black wattle) is one of the three most economically important species in southern Brazil and is used to produce chips, pellets, and tannins. This study evaluated the propagule type and indole-butyric acid (IBA) concentration in the roots of black wattle mini-cuttings. Mini-cuttings with one or two buds or apical mini-cuttings with multiple buds were treated with 2,000 mg L-1 of IBA. One-bud mini-cuttings were treated with 0; 1,000; 2,000; 3,000; or 4,000 mg L-1 IBA. Mini-cuttings were evaluated for survival and rooting percentages, number of roots, and mean length of the three largest roots after 30 days of cultivation in a humid chamber. Mini-cuttings with one bud and apical mini-cuttings with multiple buds treated with 1,000 mg L-1 IBA had the greatest rooting competence.