Moinha de carvão como substrato alternativo na produção de mudas de azaléia

Abstract

The azalea (Rhododendron simsii planch) is an ornamental plant widely used in gardens. Its most common form of propagation is through cuttings, which is influenced per many factors, both endogenous nature as exogenous. The objective of this study was to evaluate the different seasons effect, substrates and concentrations of phytoregulator IBA (Indolebutyric acid) in the seedlings azalea production. The study was conducted in the city of Formiga - MG, in September 2011 (spring), January 2012 (summer), April 2012 (autumn) and June 2012 (winter), in a greenhouse. Cuttings of azalea were used (Rhododendron simsii Planch) with 12 cm length of the part sub-apical plant, with a bevel cut on the basal part, leaving a pair of leaves at the top. After collecting the cuttings were immersed or not in solution IBA (1.500 mg L-1) for 15 seconds and placed for rooting in polystyrene trays of 128 cells containing substrates, being kept in a humid chamber. The experimental design was completely randomized in a factorial 4x3x2 (4 seasons, 3 substrates - pure ground charcoal, 50% of ground charcoal + 50% sand substrate commercial Bioplant, IBA: 0 and 1500mgL-1) with three replications and eight cuttings per plot. After 120 days, were evaluated the percentage of root cutting, shoots number and the length of the largest root. Data were subjected to variance analysis with a using of the SISVAR software (Statistical computing system) and averages compared by Tukey test at 5% significance level. According to the results, the substrate ground charcoal showed satisfactory results for these variables, making possible its use as an alternative substrate for the azalea seedlings production (Rhododendron simsii Planch.). Not necessary to use the IBA phytoregulator for the seedlings production by cutting of that species. The best time to perform the azalea cuttings, according to the obtained results was the summer