Organic seed treatment formulations enhance biotic stress tolerance in brinjal cv. CO 2

Seed enhancement technologies provide eco-friendly alternatives to synthetic protectants for improving crop establishment under stress. In the present study, organic seed pelleting and coating formulations were developed using volcanic ash (as a silicon-rich mineral source), biochar and a microbial consortium. These formulations were evaluated in brinjal (Solanum melongena L.) cv. CO 2 under biotic stresses imposed by Fusarium oxysporum and Pythium aphanidermatum. Results revealed that both pelleting and coating significantly improved seed germination, seedling vigor, root and shoot growth and biomass accumulation compared to the untreated seeds (control). Among various seed treatments, seed pelleting mixture at 500 g kg-1 seed and seed coating formulation at 4 g kg-1 seed consistently outperformed others, recording higher emergence, leaf area and chlorophyll content even under pathogen pressure. The superior performance of these treatments is attributed to the synergistic effects of silicon-mediated structural defense, nutrient mobilization by biochar, phytohormone stimulation and pathogen suppression by microbes and biocontrol agents. This study demonstrates the potential of integrating mineral-based carriers with microbial inoculants in organic seed enhancement technologies to strengthen seedling establishment and resilience against biotic stresses. Thus, eco-innovative formulations provide a sustainable strategy to reduce pesticide dependence and enhance crop productivity in solanaceous vegetables.