Enhancing Eggplant Yield Through Fertilizer Application Supplemented with Micronutrients and Plant Growth Regulator

Aim: This study aimed to evaluate the effect of micronutrients and plant growth regulator, in combination with the recommended rate of Nitrogen (N), Phosphorous (P) , and Potassium (K), on the growth and yield of eggplant.Methodology: The experiment was conducted in a farmer's field located at Barangay Guayabal, Cauayan City, Isabela, where the soil analysis had a pH of 6.15 (slightly acidic) 0.55% organic matter, 11.33 ppm Phosphorus and 210.15 ppm available Potassium and a fertilizer recommendation of 90-40-30 kg NPK ha.Treatments included the application of micronutrients Zinc Sulfate (ZnSO), Borax, Ferrous Sulfate (FeSO), Black Soldier Fly (BSF) frass, a combination of Zinc Sulfate + Borax + Ferrous Sulfate and gibberellic acid (GA), all combined to the recommended NPK rate laid out in a Randomized Complete Block Design (RCBD) with three replications.Results: Results of the study showed that treatments involving NPK + GA (T7) and NPK + ZnSO + Borax + FeSO (T6) significantly enhanced plant height at 90 days after transplanting (DAT), number of branches, fruits per plant, fruit diameter, and fruit weight.Although fruit length was not significantly affected, these two above -mentioned treatments (T6 and T7), closely followed by BSF frass (T2), produced the highest yields per sampling area.Likewise, the marketable fruit yield per 1000 m with increased by 59.23% (T6), 47.31% (T7) and 14.23% (T2) over the sole application of NPK.This emphasizes the effectiveness of micronutrient combinations and GA in improving eggplant yield. Conclusion:The supplementation of NPK with specific micronutrients significantly enhances both vegetative growth and yield in eggplant, particularly resulting in a return on investment of 65.69% with the application of 90-40-30 kg NPK ha -1 + Zinc sulfate + Borax + Ferrous sulfate).