Biofilmed Biofertilizer and Potassium Ferilizer in Reducing Basal Rot Severity and Increasing Garlic Yield on Andisol Soil

Garlic ( Allium sativum L.) is an important horticultural crop cultivated in Indonesia, domestic production remains insufficient to meet increasing demand. One major constraint in garlic cultivation is basal rot caused by Fusarium oxysporum f. sp. cepae , which significantly reduces yield and bulb quality. Environmentally friendly management practices, such as biofilmed biofertilizer (BiO 2 ) and balanced potassium fertilization, offer potential solutions to suppress disease intensity while enhancing plant growth. This study aimed to evaluate the effectiveness of the balance of BiO 2 and potassium fertilizer in controlling basal rot and increasing garlic yield on Andisol soil in Tawangmangu. The experiment was conducted from May to September 2024 using a Randomized Block Design (RBD) with four treatments: P0 (100% K (Without BiO 2 )); P1 (0% K + BiO 2 ); P2 (50% K + BiO 2 ), and P3 (100% K + BiO 2 ), each replicated six times. Data on plant growth, disease intensity, and yield components were analyzed using analysis of variance (ANOVA), followed by Duncan’s Multiple Range Test (DMRT) at a 5% significance level. The results demonstrated that BiO 2 increased K effectiveness on garlic planted in Andisol soils. The combination of 50% K+ BiO 2 was most effective in reducing basal rot severity, improving growth, and yield of garlic.