Eficiência de bactérias promotoras de crescimento no desenvolvimento inicial do milho crioulo em Pedro II-PI

Abstract

The intensification of agriculture has demanded the increasing use of nitrogen fertilizers, raising production costs and generating considerable environmental impacts. In this context, the use of plant growth-promoting bacteria (PGPB) emerges as a promising and sustainable alternative to optimize plant nutrition. This study aimed to evaluate the agronomic performance of three varieties of creole maize inoculated with different bacterial strains, focusing on plant growth promotion and biological nitrogen fixation (BNF) under controlled greenhouse conditions. Two sequential trials were conducted. In the first, nine bacterial isolates were tested in a completely randomized design. The strains with the best performance in morphological variables were selected for the second trial, which was conducted in non-sterilized soil to assess the efficacy of the isolates in competition with the native microbiota. The evaluations included shoot and root length, stem diameter, number of leaves, root volume, and dry biomass. Data were subjected to analysis of variance, and means were compared using Tukey’s test (p < 0.05). The results demonstrated that inoculation with Enterobacter sp. and Bacillus subtilis led to significant increases in growth variables, surpassing the treatments with 100% nitrogen fertilization for some parameters. The variety × isolate interaction was significant for root growth and shoot dry mass, highlighting the importance of compatibility between plant genotypes and microorganisms. These findings reinforce the potential of these strains as bioinoculants, which can be incorporated into sustainable management strategies in smallholder farming systems, especially in regions with low soil fertility and limited access to conventional inputs.