Morphophysiological response of Urochloa brizantha hybrids (Sabiá and Cayana) to inoculation with Azospirillum brasilense and Pseudomonas fluorescens

The objective was to evaluate forage production and the morphogenetic and structural characteristics of grass species from the genus Urochloa (Sabiá and Cayana), using co-commercial biofertilizers composed of Azospirillum brasilense (strains Ab-V5 and Ab-V6) and Pseudomonas fluorescens (strain CNPSo 2719), along with nitrogen fertilization using three doses (0, 25, and 50 grams/dm³) of urea as the nitrogen source, corresponding to 0, 50, and 100 kg/ha. The experiment was conducted in a greenhouse, and the grasses were harvested during the spring and summer of 2023, divided into four production cycles, with data collected every 28 days. A completely randomized design (CRD) with three replicates was used. The results were subjected to analysis of variance (ANOVA). Significant differences were observed in cycles 1, 3, and 4 for the variables Green Mass (GM), Stem Length (SL), and Stem Elongation Rate (SER). For the variables Phyllochron (PHYL), Leaf Appearance Rate (LAR), and Number of Live Leaves (NLL), statistical differences were found only in cycle 4. However, for the characteristics Dry Mass (DM) and Number of Dead Leaves (NDL), no significant differences were observed for any of the treatments or cultivars used. It was concluded that inoculation and co-inoculation with Azospirillum brasilense and Pseudomonas fluorescens, combined with nitrogen fertilization, proved effective in improving the morphogenetic and structural characteristics of the Urochloa hybrids cvs. Sabiá and Cayana.