Response of common bean to Rhizobium reinoculation in topdressing

• Published in: Revista brasileira de engenharia agrícola e ambiental 2022-04, Vol.26 (4), p.274-282
• Main Authors: Teixeira, Itamar R., Lopes, Paulo R., Sousa, Westefann S., Teixeira, Gisele C. da S.
• Format: Article
• Language: English
• Subjects: AGRICULTURAL ENGINEERING; ENVIRONMENTAL SCIENCES
• ISSN: 1415-4366; 1807-1929; 1807-1929
• DOI: 10.1590/1807-1929/agriambi.v26n4p274-282

ABSTRACT The response capacity of the bean to fix atmospheric nitrogen is questionable, mainly due to its inability to supply all the nitrogen in the flowering and grain filling phases when the crop needs it most. Thus, a new application of inoculant can keep the population of rhizobia in the soil at adequate levels, meeting all the nitrogen demands of the plant. This study aimed to investigate the nodulation capacity and the production of beans submitted to doses and reinoculation of Rhizobium in topdressing under field conditions in two growth stages. For this, an experiment was conducted using a randomized block design with four replicates in a 4 × 2 + 2 factorial scheme. The treatments consisted of the application of four doses of liquid inoculant containing Rhizobium tropici (SEMIA 4088), in the concentration 2 × 109 CFU g-1, in topdressing (0, 100, 200 and 400 mL ha-1), in two development stages (V4 and R5) of plants, and two additional treatments (inoculation via seed at a dose of 100 g of the product per 50 kg of seeds and mineral nitrogen fertilization at a dose of 16 kg ha-1 applied at sowing and 60 kg ha-1 in topdressing, divided into two stages, with half being applied at the stage V3 and the other half in V4 stage).The inoculant application increased the nodulation rates of bean cultivar BRS Cometa and the dry biomass produced by plants, using doses of 232 and 221 mL ha-1, respectively. The dose of 257mL ha-1 of the liquid inoculant applied in topdressing at the V4 stage, and the inoculation via seed provide greater common bean yield without supplementing mineral nitrogen. RESUMO A capacidade de resposta do feijoeiro em fixar o nitrogênio atmosférico é questionável, principalmente devido à sua incapacidade de fornecer todo o nitrogênio nas fases de floração e enchimento de grãos, quando a cultura mais necessita. Assim, uma nova aplicação de inoculante pode manter a população de rizóbios do solo em níveis adequados, atendendo toda a demanda de nitrogênio da planta. Deste modo, o este trabalho tem como objetivo investigar a capacidade de nodulação e a produção de feijão comum, submetido a doses de reinoculação de Rhizobium em cobertura, em dois estádios fenológicos da cultura. Para tanto, foi conduzido um experimento no delineamento de blocos casualizados, em esquema fatorial 4 × 2 + 2, com quatro repetições. Os tratamentos consistiram na aplicação de quatro doses de inoculante líquido Rhizobium tropici (SEMIA 4088), concentração de 2 × 109 CFU