Rejuvenation of mature black wattle (Acacia mearnsii De Wild.) trees is necessary as it is difficult to root from mature branches. Thus the aim of this paper was to determine the influence of stump height on promoting regrowth and the best period for cutting black wattle trees. The assays were installed in a 5 year-old, 1,0 x 1,3 m spacing black wattle plantation. A randomized block design with 6 replications and 6 plants per plot was used. Treatments constituted of various stump heights with cuttings at (a) 15 cm, (b) 30 cm, (c) 45 cm, and (d) 60 cm. The assays were installed in the autumn (March) and spring (September). The assessments were carried out in 45, 90 and 150 days, by counting stumps with sprouts and number of sprouts per stump. Tree cutting at 60 cm promoted a high regrowth rate, with approximately 90% of the stumps presenting new sprouts. Regrowth of mature black wattle obtained in the spring was better than in the autumn. These results indicated the influence of stump height and the time of the year on the regrowth ability of mature Acacia mearnsii individuals.
genetic development; stump shoots; cloning
