Nitrogen Fertilization and Inoculation of Seeds with Rhizobium tropici on the Agronomic Performance of Common Beans

Aims: This study aimed to evaluate the influence of nitrogen fertilization and inoculation of seeds with Rhizobium tropici on the agronomic performance of common bean (Phaseolus vulgaris L.).

Study Design: The experimental design consisted of a randomized block in a 4x2 factorial layout, with 4 replicates, the first factor referring to inoculant doses (0, 50, 100 and 200 mL for each 25 kg of seed), while the second refers to nitrogen fertilization (0 and 40 kg ha of N).

Place and Duration of Study: The study was conducted to the field in a no-till system area, in the southwestern region of Paraná, Brazil. The soil is classified as a Purple Latosol, with a clayey texture.

Methodology: The adopted spacing was 0.45 m between rows, and the seeding density used was 12 seeds per furrow meter. The inoculants NITRO 1000 Rhizobium tropici SEMIA 4077 and SEMIA 4088 were applied, varied according to the treatments. The cultivar used was IPR – Tangará.

Results: As for grain yield, it was observed that nitrogen fertilization did not contribute to the increase in grain yield, and higher productivity was obtained in the absence of N. This was probably due to the high content of organic matter present in the soil.

Conclusion: Nitrogen fertilization at sowing and seed inoculation with Rhizobium tropici did not influence the plant population and the 1000-grain mass. In the absence of nitrogen fertilization at sowing, pods with a longer length and higher grain yield were obtained. Inoculation of the seeds with Rhizobium tropici exerts a positive influence on plant height, number of nodes of the main stem, number of pods per plant, and number of beans per pod, the dose recommended by the manufacturer (100 mL) being efficient, with the possibility of applying a dose of 50 mL, to satisfactory results.