INFLUENCE OF PLANTING ANGLE ON THE SHOOTING AND ROOTING OF CUTTINGS OF Phyllanthus sellowianus MÜLL. ARG.

Abstract

The stabilization of natural or artificial slopes of land and shores of water courses is possible with the application of some techniques, proposed by natural engineers and soil bioengineers, which use vegetation alone or in combination with inert materials. For this reason, the vegetation to be employed needs to meet some requirements related to ecological, phytosociological and reproduction aspects.  Techniques of natural engineering use plants in different positions in relation to the horizontal line. Thus, this study aims to evaluate the effects of different planting angles of cuttings of Phyllanthus sellowianus Müll. Arg. on slope stabilization. With these results the most appropriate form of planting this species can be proposed, ie, in which biotechnical practices it can be best used. The experiment was carried out at the Forest Nursery, at the Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul. The study was done from August to November of 2007. Treatments consisted of planting cuttings of Phyllanthus sellowianus Müll. Arg. at three different angles (10°, 30° and 90°). Cuttings were 30 cm long (± 1 cm of variation), with an average diameter of 1.9 cm, and were collected in the central region of the state of RS. Two-thirds of their base were inserted into inert substrate (sand). The experimental design was completely randomized, with 30 repetitions (cuttings) for each treatment. After 90 days, the following features were analyzed: cutting survival, number, length and diameter of shoots and primary roots besides the dry mass of roots and shoots. The data were analyzed using statistical programs. The species had high values of survival, with a tendency for very positive results for stem cuttings planted at angles of 10° and 90°. Planting at an angle of 90º also provided the highest values of the sum of the length and dry mass of shoots, while the diameter and number of shoots showed no significant differences between the angles of planting. The number, the sum of the length and dry mass of roots were significantly higher in cuttings planted at a 90° angle. The diameter of the longest root presented the highest average in cuttings planted at a 10° angle, while the average length of the longest root per cutting was not statistically different between the three angles of planting.