Response of two cowpea cultivars to inoculation with nitrogen fixing bacteria in protected environment

Abstract

Due to the diversity of soil and climatic conditions of the Brazilian agroecosystems it is of great importance to select rhizobia strains efficient in nitrogen fixation and adapted to local conditions. This study aimed to evaluate in a protected environment at the Southwest of Piaui the response of two cowpea cultivars to inoculation with rhizobia strains selected and the in selection phase. The experimental design was completely randomized with four replications and treatments arranged in a 2 x 7 factorial scheme: two cowpea cultivars (BR 17 Gurgueia and BRS Guariba) and seven treatments consisting of two pre-selected strains (UFLA 3-164 and UFLA 3-154), four strains authorized by Ministry the Agriculture, Livestock and Supply (INPA 3-11B, UFLA 3-84, BR 3267 and BR 3262) and a control without mineral nitrogen and without inoculation. The nodulation, shoot dry mass and nitrogen accumulation in the shoot and nodule efficiency were evaluated. The nodulation of cultivars was influenced by treatments. Strains UFLA 3-164 and BR 3262 showed higher biomass production and nitrogen accumulation in shoots when inoculated on BRS Guariba.