Evaluation and Utilization of Bacillus siamensis NKIT-9 for Sustainable Tomato Seed Bio-priming

Bio-priming using plant growth-promoting rhizobacteria (PGPR) is an eco-friendly technique to enhance seed performance and crop production. This experiment aimed at comparing the efficiency of the three different Bio-priming methods that are Overnight soaking, Agar plug and seed coating of Bacillus siamensis NKIT-9 at different concentrations (10 6 CFU mL -1 , 10 8 CFU mL -1 , and 10 10 CFUml -1 ), for optimal tomato seed germination and enhancement of seed vigor. Among all the three different biopriming techniques, overnight soaking proved to be the most effective for enhancing tomato seed performance, achieving 98.5 % germination, a germination index of 125.88 and high seed vigor indices (SVI-I: 2103.77; SVI-II: 4171.5) at a concentration 10 10 CFUml -1 . Optimal mean germination time was observed around 5 days for this method with fast and uniform emergence. The seed coating method provided moderately improved results with highest seed germination of 85 % and lowest seed vigor indexes compared to overnight soaking method suggesting limited bacterial interaction and slower physiological activation. The agar plug method showed moderate and inconsistent performance across storage periods, resulting in reduced seed germination and vigor compared with prolonged soaking at lower temperature. Thus, overnight soaking method in Bacillus siamensis NKIT-9 could provide good growth promotion and enhancement in seed vigor in tomato. Seed coating could provide moderate improvement, whereas the use of agar plugs method shows inconsistent performance across storage duration and temperature. The findings conclude that overnight Bio-priming with Bacillus siamensis NKIT-9 is an efficient and cost-effective method for enhancing tomato seed performance and early seedling establishment.