Using Bacterial Bioagents as an Effective Alternative to Pesticides in Managing Plant Diseases

This review uses a critical lens on the possibilities of bacterial bioagents as sustainable and ecologically friendly substitutes for chemical pesticides in plant disease management. Using peer-reviewed studies released between 2000 and 2025, it compiles the present understanding of the genera Bacillus, Pseudomonas, and Streptomyces - the most researched groups for their antagonistic action against phytopathogens. To assess experimental techniques, modes of action, and performance results under laboratory, greenhouse, and field settings, a structured literature review was carried out. Special consideration was paid to the biochemical and molecular routes underlying bacterial antagonism, including antibiotic synthesis, hydrolytic enzyme secretion, nutrient rivalry, niche exclusion, and the induction of systemic resistance in plants. Evidence points toward these genera's broad-spectrum activity against fungal, bacterial, viral, and nematode pathogens; their lipopeptide synthesis and sturdy spores characterize Bacillus species; Pseudomonas and Streptomyces by their strong antifungal chemicals and strains by their metabolic variety and rhizosphere ability; and, despite significant advancement, environmental and formulation elements continue to affect variable field performance. Future studies should focus on formulation improvement, symbiotic microbial consortia, and long-term field validation. Progress in omics technologies are expected to accelerate the development of next-generation, stable biocontrol agents for food security and organic agriculture.