Biofertilizer for Citrus: 5-in-1 Liquid Application Schedule per Growth Phase

Cultivation of siam oranges and pomelo oranges in Indonesia faces challenges of declining soil fertility due to excessive use of chemical fertilizers. Biofertilizer for citrus emerges as an innovative solution to restore soil vitality while increasing crop yields. Biosolution presents the 5-in-1 Liquid Biofertilizer Formula, a consortium of five superior microbes capable of fixing nitrogen, solubilizing phosphate, producing phytohormones, and controlling soil pathogens. With the right application schedule, farmers can reduce chemical fertilizers by up to 50% and increase citrus yields by 20–30%. This article guides you in applying this biofertilizer at every growth phase of citrus.

Why Siam and Pomelo Oranges Need Biofertilizer?

Siam and pomelo oranges are leading commodities that require balanced nutrition throughout their life cycle. Unfortunately, conventional fertilization practices often lead to salt accumulation, decreased soil microbial populations, and nutrient imbalance. This is where the role of biofertilizer becomes crucial.

Role of Microbes in Increasing Nutrient Availability

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

• Rhizobium sp. – Symbiotically fixes atmospheric nitrogen on legume roots, but also provides rhizosphere effects on non-legume plants like citrus through the release of nitrogen compounds.
• Bacillus subtilis – Solubilizes bound phosphate in the soil into forms available to plants, and produces the phytohormone IAA that stimulates root growth.
• Azospirillum sp. – Associatively fixes nitrogen around the root zone, providing an additional N supply.
• Pseudomonas fluorescens – Produces siderophores that bind iron, inhibiting soil pathogens such as Fusarium and Pythium, while increasing Fe uptake by plants.
• Trichoderma sp. – Controls soil-borne fungal pathogens and decomposes organic matter into humus.

This combination makes the soil looser, rich in microbes, and capable of sustainably providing macro (N, P, K) and micro (Fe, Zn, Mn) nutrients.

Positive Impact on Fruit Quality

Regular use of biofertilizer has been shown to increase fruit size, flesh thickness, and sugar content (Brix) in siam and pomelo oranges. Additionally, plant resistance to drought and root diseases increases significantly.

Application Schedule of 5-in-1 Liquid Biofertilizer on Citrus

To be effective, biofertilizer application must be adjusted to the citrus growth phase. Here is the recommended application schedule:

Nursery Phase (0–3 Months)

In this phase, the main goal is to build a strong root system and microbial colonization in the rhizosphere.

• Dosage: 5 ml per liter of water.
• Application method: Drench 200 ml of solution per seedling into the root zone every 10 days.
• Frequency: 3 times during the nursery phase.
• Time: Morning before 10 AM or afternoon after 4 PM.

Vegetative Phase (4–8 Months)

Citrus plants begin to form canopies and productive branches. Nitrogen and phosphorus requirements increase.

• Dosage: 7 ml per liter of water.
• Application method: Drench 500 ml of solution per plant into the root zone.
• Frequency: Every 14 days, total of 4 applications.
• Tips: Combine with POC Formula for Flower & Fruit Trigger to stimulate generative growth.

Early Generative Phase (9–12 Months / Pre-Flowering)

Critical phase for flower initiation. Microbes producing phytohormones play a key role.

• Dosage: 10 ml per liter of water.
• Application method: Spray onto the soil around the base of the stem or drench 1 liter per plant.
• Frequency: 2 times with a 10-day interval.
• Note: Avoid application during heavy rain to prevent microbial washout.

Flowering and Fruiting Phase (13–18 Months)

Plants require high phosphate and potassium for fruit formation. Bacillus subtilis and Pseudomonas fluorescens help solubilize P and control pathogens.

• Dosage: 8 ml per liter of water.
• Application method: Drench 1.5 liters per plant every 14 days.
• Frequency: 3 times during this phase.
• Benefits: Reduces flower and young fruit drop.

Fruit Maintenance Phase (19–24 Months)

Fruits develop and require balanced nutrition. Microbes continuously provide nutrients gradually.

• Dosage: 5 ml per liter of water.
• Application method: Drench 1 liter per plant every 21 days.
• Frequency: 2 times.
• Results: More uniform fruit size and sweeter taste.

Post-Harvest and Rest Phase

After harvest, plants need to recover. Biofertilizer application helps improve soil and prepare plants for the next cycle.

• Dosage: 10 ml per liter of water.
• Application method: Drench 2 liters per plant, once.
• Purpose: Restore soil microbial population and decompose root residues.

Proper Application Techniques

To keep microbes alive and active, consider the following:

1. Application time: Do it in the morning or afternoon to avoid UV rays that damage microbial cells.
2. Water quality: Use clean water without chlorine. Let tap water sit overnight before use.
3. Mixing: Do not mix with chemical fertilizers or pesticides in the same tank. Allow at least 3 days interval.
4. Storage: Store the product in a cool place (15–25°C) away from direct sunlight.

Case Study: Increased Yield of Siam Oranges in East Java

A trial in a siam orange center in Batu Regency, East Java, showed that application of the 5-in-1 Liquid Biofertilizer Formula according to the above schedule increased harvest yield by up to 28% compared to the control (100% chemical fertilizer). Additionally, chemical fertilizer use was reduced by 50% without compromising fruit quality. Farmers reported greener leaves, more roots, and sweeter fruit.

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

This product has advantages:

• 5 strains in 1 bottle with a minimum density of 10⁸ CFU/ml per strain.
• Synergistic consortium covering N-fixers, P-solubilizers, PGPR, and biocontrol agents.
• Easy to apply via drenching or soil spraying.
• Compatible with organic farming systems and Good Agricultural Practices (GAP).

For more information about this product, visit the Complete Plant Nutrition Formula page.

Conclusion

Biofertilizer for citrus from Biosolution, especially the 5-in-1 Liquid Biofertilizer Formula, is the right solution to increase the productivity of siam and pomelo oranges sustainably. By following the per-phase application schedule outlined above, farmers can optimize growth, reduce chemical fertilizer costs, and improve soil health. Do not hesitate to adopt this microbiological technology for better and environmentally friendly harvests.

If you wish to discuss the specific needs of your citrus field, the Biosolution team is ready to help through free consultation. Contact us on WhatsApp for more personalized recommendations.

FAQ

1. Is the 5-in-1 liquid biofertilizer safe for citrus plants that are fruiting?

Yes, very safe. This product is based on natural microbes and leaves no chemical residues. Application during the fruiting phase actually helps improve fruit quality and reduce fruit drop.

2. How many applications of biofertilizer are ideal for citrus in one season?

For one citrus growing cycle (about 2 years until first harvest), 3–5 applications per phase are recommended, totaling about 15–20 applications. Frequency can be adjusted based on soil and plant conditions.

3. Can this biofertilizer be mixed with manure?

Yes. Mature manure (compost) can be applied together. However, avoid mixing directly in the spray tank; it is better to apply separately with a 1–2 day interval.

4. How to know if the biofertilizer is still active?

Check the expiration date on the packaging. A good product has a characteristic fermentation smell (not rotten) and does not clump. Store in a cool place to maintain viability.

5. Is this product registered with the Ministry of Agriculture?

Yes, the 5-in-1 Liquid Biofertilizer Formula is registered and meets the quality standards for biofertilizers in Indonesia. You can check the registration number on the packaging.