Assay of IAA Activity in Biofertilizer Formulations with Vermicompost Tea Adition on Maize (Zea mays L.) Growth

A biofertilizer formulated by PT Great Giant Pineapple and enriched with vermicompost tea has the potential to produce the plant growth hormone indole-3-acetic acid (IAA), which is essential for supporting plant growth and development. This study evaluated changes in IAA activity in biofertilizer formulations during a four-week storage period and examined their effects on the vegetative growth of maize (Zea mays L.). The experiment was conducted using a completely randomized design (CRD) with three treatments consisting of vermicompost tea to water ratios of 1:3, 1:5, and 1:10, each aerated for 96 hours. IAA activity was measured using UV–Vis spectrophotometry based on absorbance values and quantified using a standard curve. Plant growth data were analyzed using analysis of variance (ANOVA), followed by the Honest Significant Difference (HSD) test at a 5% significance level. Observed growth parameters included plant height, number of leaves, stem diameter, fresh weight, and dry weight, with five replications per treatment. The results showed that IAA activity in vermicompost tea-based biofertilizers increased progressively during storage. In addition, biofertilizer application significantly enhanced maize vegetative growth, with the 1:10 formulation producing the most optimal results by promoting higher IAA activity, leaf development, and biomass accumulation in both fresh and dry weights.