Microorganisms promoting plant growth in Eucalyptus urograndis

Currently, methods to enhance seedling and forest species production in plant nurseries include the use of bacterial species that promote plant growth, which may lead to the development of bioproduct formulations. This study evaluates the effect of plant growth-promoting inoculants in Eucalyptus urograndis seedlings. The products utilized were AzotoBarvar N, Potabarvar K, Phosphorbarvar P (products containing bacteria that fix nitrogen and solubilization phosphate and potassium, respectively), Bacillus subtilis and Trichoderma asperellum. The experiment was conducted by completely random design with eight repetitions, with three evaluations at 40, 70, and 90 days after sowing (DAS). Results showed that the inoculation of different plant growth-promoting microorganisms interfered with E. urograndis biomass increase compared to the control treatment. At 40 DAS, biomass and Dickson Quality Index results were superior for PotaBarvar K, T. asperellum and B. subtilis treatments. By day 70 T. Asperellum treatments proved to be more effective while AzotoBarvar N treatments were superior, by day 90. These effects are likely related to the faster action of microorganisms in PotaBarvar K, T. asperellum, and B. subtilis during early seedling development, followed by the nitrogen solubilization capacity of AzotoBarvar N at 90 DAS. In conclusion, the use of these microorganisms effectively promoted plant growth in Eucalyptus urograndis.