Agronomic performance of wheat after seed inoculation with Azospirillum brasilense

Abstract

The objective of the study was to evaluate in field conditions the agronomic performance of wheat after seed inoculation with Azospirillum brasilense, isolated or associated with nitrogen levels. The experimental design was a complete randomized block in factorial scheme 4 x 3 with four replicates. In factor A the nitrogen levels were allocated (0.0, 67.5 and 135.0 kg ha -1) and in B the Azospirillum brasilense levels (0, 100, 200 and 300 mL ha -1 ). Before harvest the number of spikes m -2 and plant height were evaluated. In harvest it was determined the spikes length, number of filled grains, sterile and full spikes, thousand grain weight, grain yield and hectoliter weight. The results presented differential effects for the variables evaluated after application of A. brasilense with or without nitrogen levels. The positive effect of A. brasilense on variables is observed, in general, with the use of levels over 160 mL ha -1 and in absence of nitrogen application. The A. brasilense influenced negatively the plant height and the number of spikes. Reductions of hectoliter weight occurred with the increase of nitrogen levels. Grain yield was positively influenced by A. brasilense in certain levels. The association of A. brasilense and nitrogen fertilizer has a negative effect on grain yield and yield increased was observed only when the bacterium is applied in absence of nitrogen fertilizer. The spike length, number of total grains per spike, sterile and filled spike and thousand grain weight is not affected by treatments.