The utilization of beneficial endophytic microorganisms presents a promising and innovative strategy for attaining environmental sustainability and fostering development. The majority of microbial bioagents are unsuitable for preparation in a suitable granular formula, and few are prepared in complicated formulas. In this work,Trichoderma viridewas simply prepared in a marketable granular formula to manageRhizoctonia solaniand improve common bean growth. The GC-MS analysis showed several antimicrobial compounds in the fungal filtrate.T. viridewas able to suppress the phytopathogenicR. solaniin the laboratory. The formula had up to 6 months of shelf-life viability. Under greenhouse conditions, the formula improved plant resistance againstR. solani. Moreover, the vegetative plant growth and physiological performance (peroxidase, polyphenol, total phenols, phenylalanine ammonia-lyase, and photosynthetic pigments) of the common bean showed obvious promotion. The formula reduced the disease incidence by 82.68% and increased the yield by 69.28%. This work may be considered a step in the right direction for producing simple bioactive products on a large scale. Moreover, the study’s findings suggest that this method can be considered a novel approach to enhancing plant growth and protection, in addition to reducing costs, improving handling and application, and maintaining fungal viability for enhancing plant growth and protecting against fungal infections.