Bacteria of the genera Azospirillum and Herbaspirillum have the ability to fix atmospheric nitrogen (N) and promote plant growth. The aim of this study was to evaluate the development and productivity of maize in response to inoculation with A. brasilense and H. seropedicae associated to N fertilizer. The experimental design was a randomized complete block with four replications and treatments arranged in a 4 x 5 factorial. The treatments consisted of inoculation of seeds (control, strain of A. brasilense - Ab-V5, strain of H. seropedicae - SmR1 and combination SmR1+Ab-V5) and N levels (0, 40, 80, 120 and 160 kg N ha-1). The basal diameter of stem, plant height, shoot dry weight and leaf area were evaluated at the vegetative and reproductive stages, and productivity. Nitrogen fertilization promoted the development of the crop until maximum nitrogen dose studied. The combined inoculation of strains of A. brasilense (Ab-V5) and H. seropedicae (SmR1) provided increments of 12% dry weight of shoot and 7% in grain yield compared to the control, indicating benefits of the combination of diazotrophic bacteria that interact differently with the plant.
Zea mays L.; diazotrophs; phytohormones
