Biofertilizer for Citrus: Field Trial Results of 5-in-1 Formula on Siam and Pomelo Oranges

Citrus cultivation in Indonesia, especially siam and pomelo oranges, faces challenges of declining productivity due to soil degradation and dependence on chemical fertilizers. Biofertilizer for citrus is an innovative solution to restore soil health while sustainably increasing yields. This article presents field trial results of the 5-in-1 Liquid Biofertilizer Formula on citrus plantations, complete with technical data and application guidelines.

Why is Biofertilizer Important for Citrus?

Citrus plants require balanced macro and micronutrients, especially nitrogen, phosphorus, potassium, and micronutrients such as zinc and boron. Chemical fertilizers provide instant nutrients, but continuous use without organic matter can lower soil pH, kill beneficial microbes, and increase attacks from soil-borne pathogens like Fusarium and Phytophthora.

Biofertilizers work synergistically with plant roots to provide nutrients naturally. The microbial consortium in the 5-in-1 Formula not only fixes nitrogen and solubilizes phosphate but also produces phytohormones that stimulate root growth and enhance resistance to abiotic stress.

Field Trial: Methodology and Location

The field trial was conducted at two locations: (1) a siam orange plantation in Selorejo Village, Malang, and (2) a pomelo orange plantation in Magetan Regency. Each location used 0.5 hectares of land divided into treatment plots (biofertilizer + 50% chemical fertilizer) and control plots (100% chemical fertilizer).

Parameters Measured:

• Plant height and stem diameter
• Number of productive branches
• Number of fruits per tree and fruit weight
• Leaf chlorophyll content (SPAD)
• Incidence of root and wilt diseases

Biofertilizer application was done by drenching the root zone with 5–10 ml per liter of water every 14 days, starting from the vegetative phase until fruit formation. A total of 5 applications per growing season.

Field Trial Results: Data and Analysis

Yield Increase

For siam oranges, the treatment plots produced an average of 28.5 kg of fruit per tree, while the control only yielded 22.8 kg — a 25% increase. Meanwhile, pomelo oranges showed a 22% increase with an average fruit weight of 1.8 kg per fruit (control 1.5 kg).

Reduction in Chemical Fertilizer

With a 50% reduction in chemical fertilizer dosage, plant growth remained optimal. In fact, leaf chlorophyll content in the treatment was 15% higher than the control, indicating better photosynthetic efficiency.

Disease Suppression

The incidence of Fusarium wilt disease in the treatment decreased by up to 70% due to the antagonistic activity of Trichoderma sp. and Pseudomonas fluorescens. Plant roots were also denser and healthier.

Mechanism of the Microbial Consortium in Enhancing Citrus Production

The 5-in-1 Formula contains five superior microbial strains that work synergistically:

• Rhizobium sp. : Fixes nitrogen from the air and provides it to plants through root nodules. Although citrus is not a legume, Rhizobium also produces growth-promoting compounds.
• Bacillus subtilis : Solubilizes bound phosphate in the soil into forms available to plants, stimulates root branching by producing the phytohormone IAA.
• Azospirillum sp. : Fixes nitrogen associatively around the root zone, supplying additional N throughout the growing cycle.
• Pseudomonas fluorescens : Produces siderophores that bind iron, inhibiting pathogen growth, while also triggering systemic resistance in plants.
• Trichoderma sp. : Colonizes the rhizosphere, decomposes organic matter, and directly combats soil-borne fungal pathogens.

This combination ensures the availability of macro and micronutrients, along with natural protection against diseases. As a result, citrus plants are more vigorous, fruits are larger, and taste quality improves.

How to Apply Biofertilizer on Citrus

Dosage and Frequency

• Dosage: 5–10 ml per liter of water (1 bottle cap for 1 liter).
• Method: Drench the root zone with 200–300 ml per tree (depending on age).
• Frequency: Every 10–14 days, starting 2 weeks after planting until harvest. At least 3–5 applications per season.
• Best time: Morning (before 10 AM) or afternoon (after 4 PM) to avoid direct UV rays that can kill microbes.

Tips for Success

• Ensure the soil is moist before application.
• Do not mix biofertilizer with chemical fungicides simultaneously; allow at least 3 days interval.
• Store the product in a cool, shaded place (temperature <30°C).

Advantages of the 5-in-1 Formula Compared to Other Biofertilizers

This product has a microbial density of 10⁸ CFU/ml per strain, well above the minimum standard for biofertilizers (10⁷ CFU/ml). The consortium of five strains ensures complete functions: N fixation, P solubilization, root stimulation, and biocontrol. Field trial results show a 20–30% increase in yield for various crops, including citrus. Additionally, using biofertilizer can reduce chemical fertilizer usage by up to 50%, saving farmers' production costs.

Farmer Testimonial

Mr. Sukirno, a pomelo orange farmer in Magetan, reported that after two seasons using this biofertilizer, his fruits were larger and sweeter. "I used to use a lot of chemical fertilizer, and the soil became hard. Now the soil is loose, roots are abundant, and yields have increased. I save almost half on fertilizer costs," he said.

Conclusion

The 5-in-1 Liquid Biofertilizer for citrus has proven effective in increasing the productivity of siam and pomelo oranges, while reducing chemical fertilizer use and disease incidence. With a comprehensive microbial consortium mechanism, this product is the right solution for farmers who want to transition to sustainable agriculture without sacrificing yields.

For more information and free consultation, contact the Biosolution team via WhatsApp. Also get Flower & Fruit Trigger POC Formula as an organic nutrient supplement for the generative phase of your citrus plants.

Visit the product page to see full specifications and ordering instructions.