Associação de Azospirillum brasilense e de nitrogênio em cobertura na cultura do milho

Abstract

The bacterial Azospirillum brasilense also produce hormones to plants is also capable of fixing atmospheric nitrogen which corn when inoculated into the culture becomes a promising technique for the development of the plant and to increase productivity. Thus, the objective of this study was to evaluate the effects and ways of inoculation of A. brasilense (strain BR11005 - Sp 245) and doses of nitrogen topdressing in corn. The experiment was carried out in Guarapuava (PR) in the 2011/2012 season with a randomized block design with four replications in a factorial 3 x 5 with two ways of inoculation (seed and furrow) and noninoculated controls and use of 0, 75, 150, 225, 300 kg ha?¹ N in coverage, totaling 15 treatments. Were evaluated: height of insertion of spike, plant height, stem diameter, relative content of chlorophyll A, B and total leaf area index, index silking, number of rows per ear, number of kernels per row, number of grains per spike, thousand grain weight, incidence of grains and productivity. It was concluded that inoculation with A. brasilense regardless of the method of application (via seed or furrow) did not provide statistically significant increases in corn yield only in influencing plant height. The maximum efficiency of 11879 kg ha?¹ of corn grains would be achieved with a dose of 222 kg ha?¹ nitrogen. Inoculation with Azospirillum brasilense can generate savings in the use of broadcast coverage nitrogen.