Formas de aplicação de inoculante Bradyrhizobium na cultura da soja

Abstract

Inoculation is one of the main cultural practices in legumes. The objective of this work was to verify if the different forms of application of liquid inoculant containing bacteria of the genus Bradyrhizobium have effects on soybean crop. The experimental design was a randomized complete block with 9 treatments with five replications. The treatments were composed by the application of liquid inoculant (B. japonicum and B. elkanii), at a concentration of 5x109 CFU mL-1 (4x the recommended dose), on the seeds, in the soil, application after seedling emergence by leaf. (4x the recommended dose), in the vegetative stages V1, V3, V5 and V8, besides the application of Nitrogen in the doses of 200 and 300kg / ha-1. Chlorophyll content, stem diameter, plant height, number of leaves and leaf area, number of viable and unfeasible total nodules, root dry mass and part area were determined. Based on the Scott-Knott test at 5% probability, significant differences were observed between treatments for the variables height, shoot dry mass, root dry mass, diameter, leaf area, number of nodules and number of viable nodules. Inoculation, soil and leaf application at stage V3 reached the highest averages compared to other treatments. For number of total nodules, treatments with seed inoculation and vegetative stages V1, V3, V5 and V8 presented higher means than the control. The stem diameter, as well as the height of the plants, was higher in the inoculation, seed inoculation via soil treatments, and in the V1, V3 and V5 stages, which obtained the highest averages in relation to the control. The variables, shoot dry mass, root dry mass, leaf area, number of viable and unfeasible nodules, leaf number and chlorophyll content did not differ significantly from the control.