Effects of indolebut yric acid on rooting of leaf and stem cuttings of pariparoba (Piper umbellatum L.)

Abstract

Piper umbellatum L. is a Brazilian native species whose medicinal properties confer it with potential for economic exploitation. The study of propagation methods for this species is fundamental to avoid its exploitation from being restricted to extractivism. The objective of the present research was to evaluate the propagation of P. umbellatum by leaf and stem cuttings and the effect of indolebutyric acid (IBA) on their rooting. The experimental design consisted of a 2x3 factorial scheme, with two types of cuttings (leaf and stem) and three IBA treatments (0, 2000, 4000 mg. L-1). Leafless stem cuttings were prepared at a length of 15 cm. Leaf cuttings comprised leaf petiolo and limbo, reduced to a fifth of its original area. After 50 days from planting, in treatment without AIB, leaf cuttings had the greatest rooting percentage (22.5%) when compared to stem cuttings (7.5%). At the concentration of 2000 mg.L-1, there was an increase in rooting percentages for both types of cuttings, with higher rates for leaf cuttings (40%). At the concentration of 4000 mg.L-1, stem cuttings had a better rooting performance, whilst rates of leaf cuttings decreased. On average, leaf cuttings had a greater number and length of roots than stem cuttings. Leaf cuttings demonstrated little developed and small-sized sprouts at all treatments. The use of this type of propagule should be restricted to conditions where there is a limitation in the availability of stem cuttings for the propagation of P. umbellatum.