<![CDATA[Background: Cacao (Theobroma cacao L.) is an economically important plantation crop in Indonesia, but its growth is constrained by seedling quality and the acidic, nutrient-poor conditions of Red-Yellow Podzolic (RYP) soil. Therefore, appropriate fertilization is essential to support seedling growth. Objective: This study aimed to evaluate the interaction between GDM liquid organic fertilizer (LOF) and NPK 16-16-16 fertilizer, as well as their individual effects, on the vegetative growth of cacao seedlings. Methods: The experiment was arranged in a 4 x 4 factorial Completely Randomized Design with three replications using four GDM LOF concentrations and four NPK 16-16-16 application rates. Plant height, leaf number, stem diameter, root length, root volume, fresh weight, and dry weight were measured and analyzed using analysis of variance followed by Tukey’s Honestly Significant Difference test at the 5% level. Results: The results showed that the interaction between GDM LOF and NPK 16-16-16 significantly affected all growth parameters except root length, which was influenced only by the individual effects of each treatment. The combination of 25 mL L-1 GDM LOF and 12 g polybag-1 NPK 16-16-16 consistently resulted in the best overall growth performance of cacao seedlings. Conclusions: Overall, combined organic and inorganic fertilization improved cacao seedling growth on RYP soil, indicating that GDM LOF and NPK 16-16-16 can serve as an effective and cost-efficient fertilization strategy.]]>
