Use of Trichoderma and Bacillus in Sustainable Biological Management for the Production of Sunflower (Helianthus annuus L.) in the Amazon

Objective: This study aimed to evaluate the effects of the combined application of the microorganisms Trichoderma asperellum and Bacillus subtilis on the development of sunflower (Helianthus annuus L.), aiming at sustainable alternatives to the use of chemical fertilizers. Theoretical Framework: The research is based on the potential of plant growth-promoting microorganisms, such as Trichoderma and Bacillus, which act in nutrient solubilization, phytohormone production, and biological control of phytopathogens. These microorganisms contribute to agricultural sustainability by reducing dependence on chemical inputs. Method: The experiment was conducted in a randomized block design with four treatments and three repetitions in Tomé-Açu (PA), from May to August 2023. Seeds were treated with commercial microorganisms and evaluated for plant height, stem diameter, leaf area, and fresh mass of stem, leaf, and capitulum. Results and Discussion: The co-inoculation of Trichoderma + Bacillus showed better results in variables such as stem diameter, leaf area, and fresh mass of vegetative and reproductive parts. The control treatment stood out in height during the early stages, but the microbial combination outperformed the others at the end of the cycle, demonstrating synergy between the bioinoculants. Research Implications: The joint application of these microorganisms shows promise for sustainable sunflower management, with potential for increased productivity and reduced use of chemical fertilizers. Originality/Value: The study contributes to the literature by demonstrating the positive impact of co-inoculation of bioinoculants in Amazonian conditions, promoting gains in productivity and sustainability in sunflower cultivation.