Biofilmed biofertilizer and phosphate in NK combined compound fertilizer to reduce basal rot severity and enhance garlic yield on andisol soil

Garlic (Allium sativum L.) is an important commodity in Indonesia, yet its production remains insufficient to meet market demand. One of the main constraints to garlic productivity is basal rot disease caused by Fusarium oxysporum f. sp. cepae, which reduces bulb yield and quality. The application of biofilmed biofertilizer (BiO₂) combined with phosphate in NK compound fertilization has the potential to suppress disease severity while improving plant growth and yield. This study aimed to evaluate the effectiveness of BiO₂ and potassium fertilization in controlling basal rot disease and enhancing garlic productivity on Andisol soil in Tawangmangu. The experiment was conducted from May to September 2024 using a Randomized Block Design with four treatments: P0 (100% NK, 0% P + BiO₂), P1 (100% NK, 50% P + BiO₂), P2 (100% NK, 100% P + BiO₂), and P3 (100% NP), each replicated six times. Observations included plant growth, disease incidence and severity, and yield components. The results showed that treatment P2 was the most effective in reducing disease severity while maintaining high yield performance. The application of BiO₂ also increased plant height and leaf number, indicating that integrating BiO₂ with balanced NK fertilization is an effective strategy to enhance garlic productivity on Andisol soils.