Rhipsalis grandiflora Haw. (Cactaceae) propagation by setem cuttings

Abstract

The genus Rhipsalis is being cultivated as a potted plant since the view of the pendant branches with coloured flowers and fruit is very appreciated. Considering that there is no information about the production of rooted propagules of these species, the goal of this work was to evaluate the development of stem cuttings, stimulated by the application of plant growth regulators. The indolebutyric acid (IBA) was tested at 0; 4.07; 5.81, and 11.63 mmol L-1 and the naphthaleneacetic acid (NAA) at 0; 4.53; 6.47, and 12.94 mmol L-1 for their activity in promoting roots on apical stem segments of Rhipsalis grandiflora Raw. The base of stem cuttings was dipped into auxin solutions mixed with talc and each one was partially embedded in fir bark (Pinus sp) and fern fiber (1:1) in polystyrene propagation flats, placed throughout the rooting period in a greenhouse (50% shading), at 60-90% of relative humidity and temperatures from 20 to 25ºC. The experimental design was a completely randomised with eight treatments (twelve replicates), with samplings at 0; 20; 50; 80, and 150 days. The results indicate no differences between IBA and NAA regarding the dry mass of roots, but an increase in for concentrations of 0 and 4.07 mmol L-1 of IBA and 0 and 4.53 mmol L-1 of NAA, in relation to treatments with auxins. Stem cuttings treated with 4.07 mmol L-1 of IBA and 4.53 mmol L-1 of NAA, had greater dry mass of shoot bud differentiation in relation to those treated with 0 mmol L-1.