Association of phosphates and inoculation with Bacillus subtilis and its effect on the growth and productive performance of common bean

ABSTRACT The common bean crop is responsive to phosphorus (P) fertilization, and studies are needed to identify supply managements that minimize the dependency of soluble phosphates, which are costly and have low residual effect. The aim of the study was to evaluate the growth and productive performance of the common bean crop as affected by sole or associated applications of soluble and rock phosphates, in the presence and absence of Bacillus subtilis inoculation. The experiment was carried out in pots in a greenhouse, using a Red Latosol with an initial concentration of 6.61 mg P dm-3. The experimental design was completely randomized in a factorial scheme 6 × 2, in which the sources of phosphorus were studied, at a dose equivalent to 120 kg P2O5 ha-1: ‘triple superphosphate’ (TSP, soluble), ‘Itafós’ (ITA, rock), ‘Gafsa’ (GAF, rock), TSP + ITA, TSP + GAF, and one control (no P fertilizer) - with and without inoculation of Bacillus subtilis and four replications. Better results for shoot and root growth, besides productive performance, were obtained with the application of TSP, solely or combined with ITA and GAF. For the soluble source, the inoculation with B. subtilis also promoted higher growth, although not influencing the grain yield, which was only increased by inoculation when ITA was solely used.