Comprimento de estacas e concentrações de ácido indolbutírico (AIB) na propagação vegetativa de pitaia

Abstract

Although there has been great expansion in the cultivation of pitaya both in Brazil and in other countries, scientific information is needed to help define production systems which are more suited to edaphoclimatic conditions in Brazil. This study therefore aimed to evaluate the effect of the application of indolebutyric acid (IBA) and of the length of cuttings on rooting in the pitaya. The experiment was conducted under greenhouse conditions. Four dosages of IBA were tested (0, 1500, 3000 and 4500 mg dm-3 IBA) and two sizes of cutting: small (5 to 14 cm) and large (17 to 26 cm); levels of both factors being arranged in a 4 x 2 factorial design in four randomised blocks. Eighty-five days after the experiment was set up, a phenological analysis of the plants was carried out, and the lateral cladodes collected. The following phenological characteristics were evaluated: length of the longest root (CR), root dry weight (MSR), shoot fresh weight (MFPA), shoot dry weight (SDM), total dry weight (TDM), number of lateral cladodes issued (NEL), sum of the length of cladodes (SCC) and shoot to root ratio (SRR). At the end of the study it was found that the size of cuttings and the application of IBA affect rooting in the pitaya. Plants propagated from large cuttings (17-26 cm) and treated with 3.000 mg dm-3 IBA show the best rooting.