Productivity and nodulation of promising lineages of the Carioca bean group inoculated with Rhizobium tropici or supplemented with nitrogen fertilizer

Abstract

The aim of this study was to evaluate the nodulation and productivity of lineages of the bean group Carioca inoculated with Rhizobium tropici or fertilized with nitrogen. The experiments were conducted in Dourados, MS, Brazil, in 2008 (experiment 1) and 2009 (experiment 2). The experiment was performed in randomized blocks in triplicate in a 2 x 14 factorial, in which the factors were two different forms of nitrogen supply (mineral N or Rhizobia inoculation). We used 14 different bean lineages. The seeds were inoculated with a mixture of the R. tropici strains CIAT 899 (SEMIA 4077) and PRF 81 (SEMIA 4080). For the majority of the new strains tested, the grain productivity of the common bean were similar for plants inoculated with R. tropici and those fertilized with 80 kg N ha-1. The different nodulation and phytotechnical parameter behaviors of some strains demonstrated that the source of N (inoculation of Rhizobium or nitrogen fertilization) in studies on breeding for the selection of bean cultivars can directly affect their yield potential.

Keywords

• Phaseolus vulgaris; Biological fixation of nitrogen; Genotypes.