Azospirillum brasilense inoculation methods in corn and sorghum

ABSTRACT The Azospirillum brasilense inoculation is usually carried out via seed. However, this bacterium presents passive penetration in the plant, what makes it possible to inoculate the crops using other methods. This study aimed to evaluate the influence of A. brasilense inoculation methods on the emergence and initial growth of corn and sorghum, under greenhouse conditions. A randomized block design, with four replications, in a 4 x 2 factorial scheme, was used. The first factor consisted of a control treatment (without inoculation) and three inoculation methods: via seed, via sowing furrow and via leaf spray. The second factor was composed by two hybrids of corn and two of sorghum. The application of A. brasilense to the seed can reduce the emergence percentage and the emergence speed index of corn seedlings, depending on the genotype, but its application does not influence the initial growth of the plants. The A. brasilense inoculation via seed and via sowing furrow can reduce the emergence and increase the mean emergence time of sorghum seedlings, depending on the genotype. The A. brasilense inoculation via seed results in an increase in the dry mass of the root system of sorghum plants.