PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

Maize is a global staple food widely used as animal feed, biofuel, and a raw material in various industries. Gibberellic Acid 3 (GA3) is crucial in regulating plant growth. This study aimed to evaluate the impact of GA3 concentrations and planting distances on maize productivity, providing insights to optimize production for quality and profitability. The experiment was conducted at the ISU Compound, Cabagan, Isabela, from March to July 2023. It is a 4 × 2 factorial in a Randomized Complete Block Design (RCBD) with eight treatment combinations and three replications. Factor A consisted of four GA3 concentrations (control, 175 mL, 200 mL, and 225 mL), while Factor B included two planting distances (20 cm × 20 cm and 20 cm × 25 cm). Data were analyzed using two-way ANOVA and Tukey’s LSD at a significance level of P < 0.05. Results indicated that GA3 application significantly influenced plant height (PH), demonstrating that higher concentrations of GA3 promoted greater vegetative growth, while the other parameters were not significantly affected. Meanwhile, the computed yield (CY) was significantly affected by planting distance and the interaction effect between GA3 concentration and spacing. The combination of 175 mL GA3 application with a 20 cm × 25 cm planting distance resulted in the highest yield, suggesting that this treatment enhances maize productivity while maintaining efficient plant spacing. Thus, it is recommended for optimizing maize production, ensuring better growth performance, and higher economic returns.