Agronomic characteristics of wheat due to Azospirillum brasilense, humic acids and nitrogen in greenhouse

The objective of this study was to investigate the effect of the combined use of Azospirillum brasilense, humic acid and different levels of nitrogen on agronomic characteristics of wheat under greenhouse conditions. The experiments were installed on May 21, 2011 and proceeded to harvest on September 13, 2011. The experimental design was a randomized complete block in a 4 x 4 factorial design with four replications. The first factor relates to the combination of strain Ab-V-5 of A. brasilense with humic acids, with the following treatments: control, Ab-V-5, humic acid and Ab-V-5 + humic acid and the second factor refers to nitrogen levels (0, 30, 60 and 90 kg ha(-1) N). Most variables in the analysis had a positive linear effect of treatments depending on nitrogen fertilization, and only for variable weight of hundred grains, the negative effect was linear. There were no significant differences between the variances in grain production. It was concluded that the combined use of Ab-V-5 + humic acid promotes the production mainly of dry leaves and are not responsive to nitrogen fertilizer for other productive components under study, as well as grain yield.