Optimizing Biosaka Elicitor Concentration for Enhanced Growth and Yield of Cherry Tomato (Solanum lycopersicum L. var. cerasiforme).

<b>Background and Objective:</b> Prolonged utilization of chemical fertilizers can harm the soil and disturb the equilibrium of nutrients, resulting in a decline in cherry tomato yield. To enhance the growth of cherry tomato plants, it is necessary to add organic chemicals. The research aimed to determine the best elicitor biosaka concentration to apply to evoke the plant growth of cherry tomatoes (<i>Solanum lycopersicum</i> L. var. <i>cerasiforme</i>). <b>Materials and Methods:</b> This study employed a complete random design with four treatments of biosaka formula: B0 (control, water), B1 (1.5 mL/L), B2 (2.5 mL/L), B3 (3.5 mL/L) and B4 (4.5 mL/L). Twenty-day-old tomato seedlings were transplanted into polybags filled with a compost and husk charcoal mixture. Biosaka application was done every four days by spraying at a 0.5 m distance, starting from the first day after transplanting. Lycopene levels were measured using a UV-vis spectrophotometer at 417 nm after a series of solvent extractions. Data were analyzed using ANOVA for significant effects. <b>Results:</b> The biosaka concentration of 4.5 mL/L gives the highest results for the variables of treatments such as the plant height is up to 167.8 cm, the number of petioles is 62.8 petioles, the number of fruit is 19.6 and the age at flowering is 44.4 days. The biosaka concentration of 4.5 mL/L gave the highest yield for the variable plant height of 167.8 cm, the number of petioles 62.8, the number of fruits per plant 19.6, the initial flowering age of 44.4 days, the wet weight of the plant was 740 g and the dry weight of the plant was 125.1 g. <b>Conclusion:</b> The optimal concentration of biosaka (4.5 mL/L) significantly improved cherry tomato growth and yield, resulting in increased plant height, number of petioles and fruit count. It also accelerated the initial flowering age and enhanced both wet and dry plant weights. This indicates that 4.5 mL/L of biosaka effectively promotes the growth and productivity of cherry tomato plants.