Qualidade de sementes de milho em resposta à adubação nitrogenada e à inoculação com bactérias diazotróficas

Abstract

In the search for elevating high current levels of productivity and reduction in production costs of corn seeds in Brazil, new technologies are being incorporated into the production system. The aim of this study was to evaluate the physiological quality of seeds of maize in response to nitrogen fertilization and inoculation with Azospirillum brasiliense and Herbaspirillum seropedicae. Two experiments were installed, and in the first the design adopted was a randomized block, and in the second experiment, the design used was a completely randomized, both with nine treatments (control without N and without inoculation, control without N and with A. brasilense, control without N and with H. seropedicae, 30 kg N ha-1 in sowing, 30 kg N ha-1 in sowing + A. brasilense, 30 kg N ha-1 in sowing + H. seropedicae, 30 kg N ha-1 in sowing + 90 kg N ha-1 in topdressing, 30 kg N ha-1 in sowing + A. brasilense + 90 kg N ha-1 in topdressing; 30 kg N ha-1 in sowing + H. seropedicae + 90 kg N ha-1 in topdressing) and four replications. The variables evaluated were: percentage and first count of germination, dry mass and length of seedling, accelerated aging, cold test and electrical conductivity. The dry mass production are affected by inoculation with diazotrophic bacteria in association with nitrogen fertilization. Inoculation of corn seeds with A. brasilense, H. seropedicae and the use of nitrogen fertilizer promotes increase in productivity of corn seed to the extent of 4.73; 5.17 to 8.90%, respectively. The use of A. brasilense improves the physiological quality of seeds of maize by cold test without soil.