Inoculation methods and agronomic efficiency of <i>Azospirillum brasilense</i> Strain Az39 for corn crop under different brazilian edaphoclimatic conditions

Abstract

In recent years, the research that look for biological technologies that guarantee sustainable agricultural production and application methods that maximize the benefits of adopting this practice has been increasing. This study aimed to assess, for the first time, the different application methods and agronomic efficiency of Azospirillum brasilense Az39 for corn cultivation in Brazil. Four trials were conducted under different soil and climate conditions in the 2017 - 2018 harvests (Santa Maria-RS and Ibirubá-RS, Brazil) and 2019 harvest (Londrina-PR and Primavera do Leste-MT, Brazil). The experimental design used was a randomized block, evaluating three inoculation treatments with 10 replicates each: control = non-inoculated ; TS =  inoculation with A. brasilense Az39 via corn seed; and Foliar500 = foliar application of A. brasilense Az39 at the V4 stage of corn. The A. brasilense Az39 strain was effective in Brazilian soils and increased corn grain yield in all evaluated areas. Furthermore, foliar application of this strain at a dosage of 500 mL ha^-1 resulted in greater increases compared to seed treatment. Thus, the A. brasilense Az39 strain is a promising bio-input technology for Brazilian agriculture.