Efficacy of Biocontrol-Based Foliar Elicitors in Reducing Disease Incidence, Severity, and Enhancing Survival in Tomato (<em>Solanum lycopersicum</em> L) Varieties

Solanum lycopersicum L. production is frequently challenged by complex bacterial, fungal, and viral pathogens, leading to significant yield losses. This study evaluated the efficacy of three foliar elicitor treatments, Activane®, Micobiol®, and Stemicol®, in reducing disease incidence, severity, and improving plant survival in two tomato varieties, Saladette (Potosí) and Bola (Arameo), under greenhouse conditions. A completely randomized design with four treatments and four replications per variety was implemented. Disease incidence and severity were monitored using standardized scales, while pathogen identification was conducted through morphological observations and molecular methods, including 16S rDNA, ITS region sequencing, and PCR/RT-PCR assays for begomoviruses. Elicitor applications consistently reduced pathogen frequency and severity across bacteria (Enterobacter cloacae, Pseudomonas syringae, Xanthomonas euvesicatoria), fungal (Oidiopsis taurica, Alternaria solani, Fusarium oxysporum, Botrytis cinerea), and viral (Tomato yellow leaf curl virus, Tomato mottle virus) species. Among treatments, Micobiol® and Stemicol® achieved the greatest reductions in disease metrics and enhanced cumulative plant survival, reaching up to 94% in Saladette and 92% in Bola. Correlation analyses revealed differential suppression of specific pathogens, indicating that elicitor-induced priming selectively enhances plant defenses. The results demonstrate that biocontrol-based foliar elicitors are effective tools for integrated disease management, offering a sustainable alternative to chemical pesticides while promoting plant resilience and productivity.