Impact of the application of rhizobacteria in bean cultivars: potential for sustainable management

Abstract

The use of bacterial inoculants has great potential to improve yield and sustainability; however, application forms still face bottlenecks, such as the standardization of methods and compatibility with different varieties of bean. The objective of this study was to evaluate the growth and yield of bean cultivars subjected to inoculation and co-inoculation with rhizobacteria. The experiments were carried out using a randomized block design, with three replicates. Treatments consisted of four bean cvs. (BRS FC 402, BRS Estilo, BRS Pitanga, and BRS Esteio), subjected to inoculation with Rhizobium and co-inoculation with Azospirillum, applied to seed or soil, plus eight additional treatments with a mineral N source and its absence (control) for each cvs. The use of co-inoculation of R. tropici with A. brasilense promoted an improvement in the morphophysiological and agronomic characteristics, attributed to the ability of rhizobial bacteria to supply nitrogen to plants and to Azospirillum through hormonal action. The cvs. BRS Estilo and BRS Esteio had the best grain yields when co-inoculated via soil, 2049 and 1831 kg ha−1, respectively. Co-inoculation with R. tropici + A. brasilense applied to the soil can be used as an exclusive source of N supply in the bean, contributing to lower costs and more sustainable production.