Shallot Biofertilizer: POC Formula for Large Bulbs and Long Storage

Shallot farmers in Brebes know well that bulb quality—size, weight, and storage life—determines the selling price. So far, chemical fertilizers have been relied upon to boost growth, but they often leave residues that actually shorten bulb storage life. This is where shallot biofertilizer becomes a smart solution. With a biological approach based on microbes and organic compounds, biofertilizer not only increases bulb weight by 15–25% but also strengthens postharvest bulb resistance. This article thoroughly discusses the mechanism of action, application, and advantages of Biosolution's POC Bulb Quality Formula—the right choice for farmers who want abundant and long-lasting harvests.

Why Are Chemical Fertilizers Not Enough for Large Bulbs and Long Storage?

Chemical fertilizers indeed provide high amounts of macro nutrients such as nitrogen, phosphorus, and potassium. However, their continuous use without organic matter leads to soil degradation, decreased microbial activity, and salt accumulation. As a result, shallot bulbs are susceptible to bulb rot diseases (such as Fusarium spp.) and lose weight during storage. Moreover, chemical fertilizers do not stimulate the production of natural growth hormones necessary for uniform and large bulb formation. A biological approach through biofertilizer offers a more holistic solution.

What Is Shallot Biofertilizer and How Does It Work?

Biofertilizer is a formulation containing living microorganisms (such as Plant Growth Promoting Rhizobacteria/PGPR) or bioactive compounds beneficial to plants. Unlike chemical fertilizers that directly provide nutrients, biofertilizer works indirectly: producing growth hormones, increasing soil nutrient availability, and inducing plant resistance to stress. Biosolution's POC Bulb Quality Formula is a liquid organic fertilizer (POC) specifically formulated for the shallot bulbing phase.

Active Composition of POC Bulb Quality Formula

This formula contains three main components that work synergistically:

1. PGPR Consortium: A collection of rhizosphere bacteria such as Bacillus spp. and Pseudomonas spp. that produce auxin (IAA), gibberellin, and cytokinin hormones. These hormones stimulate bulb cell division and accelerate bulb formation.
2. Seaweed Extract: A source of natural cytokinin (zeatin) and micronutrients such as zinc (Zn), boron (B), and manganese (Mn). Cytokinin plays a role in cell division and delays leaf senescence, so photosynthesis lasts longer and more assimilates are allocated to bulbs.
3. Humic and Fulvic Acids: Organic compounds that act as nutrient carriers, increase soil cation exchange capacity, and stimulate root growth. Healthy roots absorb water and nutrients more efficiently, supporting optimal bulbing.

Mechanism of Action in Shallot Plants

When applied foliarly or as a soil drench, PGPR immediately colonize the leaf surface or rhizosphere. These bacteria produce hormones that are translocated to vascular tissues, triggering the expression of genes related to bulb enlargement. Seaweed extract provides cytokinin signals that strengthen bulb sink strength, so more photosynthates are diverted to bulbs. Humic and fulvic acids enhance the absorption of micronutrients essential for enzymes involved in starch and protein formation in bulbs. As a result, bulbs grow uniformly, weight increases, and total soluble solids (TSS) content is higher—correlating with longer storage life.

Advantages of POC Bulb Quality Formula for Brebes Farmers

Shallot farmers in Brebes face specific challenges: soil already saturated with chemical fertilizers, Fusarium wilt disease attacks, and price fluctuations that demand prime harvest quality. Here are the main advantages of POC Bulb Quality Formula:

• Yield per plant increases by 15–25%: Field trial data show a significant increase in fresh bulb weight compared to chemical fertilizer controls.
• Reduces flower/fruit drop by up to 30%: Natural hormones in the formula stabilize flowering and bulb formation, reducing drop.
• Easy application: Simply spray onto leaves (foliar) or drench into soil at a dose of 3–5 ml per liter of water, every 7–10 days in the morning before 10 AM.
• Organic and safe for certification: No harmful chemical residues, suitable for organic farming and environmentally friendly.
• Increases bulb storage life: Higher starch and antioxidant content makes bulbs less prone to rot during storage.

Proper Biofertilizer Application for Maximum Results

For optimal biofertilizer performance, follow these application guidelines:

Application Timing

Start application when plants are 21–25 days after planting (DAP), i.e., entering the bulb initiation phase. Continue every 7–10 days until 1 week before harvest. Avoid application during rain or direct scorching sun.

Dosage and Spray Method

Mix 3–5 ml of POC Bulb Quality Formula per liter of water. Stir well, then spray onto the entire lower and upper leaf surfaces until evenly wet. For 1 hectare of land, approximately 300–500 liters of spray solution is needed per application. If drenching, pour 200–300 ml of solution per clump.

Combination with Other Products

For more optimal results, combine with Complete Liquid Biofertilizer Formula as a basic nutrient during the vegetative phase. Use alternately: vegetative phase (0–20 DAP) with the 5-in-1 fertilizer, then bulbing phase (21 DAP–harvest) with POC Bulb Quality Formula.

Case Study: Field Trial in Brebes Farmer's Land

In the 2024 growing season, a trial was conducted in Kersana Village, Brebes, on 0.5 hectares of land. The farmer used POC Bulb Quality Formula (dose 4 ml/l, every 7 days) on the Bima Brebes variety. Results:

• Average bulb weight per clump was 125 grams, up 20% compared to the control (104 grams).
• Bulb diameter was more uniform (2.5–3 cm), meeting export standards.
• Bulb storage life at room temperature reached 3 months without rot, while the control only lasted 2 months.

Farmers also reported a decrease in Fusarium wilt attacks because PGPR induced systemic resistance in plants.

FAQ: Common Questions About Shallot Biofertilizer

Can biofertilizer completely replace chemical fertilizers?

Biofertilizer does not replace chemical fertilizers 100%, but it can reduce chemical fertilizer doses by up to 50%. For optimal results, combine with basic organic fertilizer and low-dose chemical fertilizers. This integrative approach maintains soil health and long-term productivity.

How long does it take to see the effects of biofertilizer on shallots?

Changes begin to appear after 2–3 weeks of application: leaves are greener, stems are sturdier, and bulbs start to enlarge uniformly. Significant increases in harvest weight are seen after 4–5 applications.

Is biofertilizer safe for young plants?

Yes, it is safe. POC Bulb Quality Formula is not phytotoxic. Even on seedlings, PGPR helps early root development. Start application when plants are 3 weeks old for best results.

How should diluted biofertilizer be stored?

The biofertilizer solution should be used within 24 hours after mixing with water. Store in a shaded, closed container. Do not store the solution for more than 2 days as microbes may die.

Can biofertilizer be mixed with chemical pesticides?

It is best not to mix directly because chemical pesticides can kill microbes. Apply biofertilizer first, then apply chemical pesticides 2–3 days later. For safe results, use organic pesticides.

Conclusion

Shallot biofertilizer, especially Biosolution's POC Bulb Quality Formula, offers an effective biological solution for producing large bulbs with long storage life. With a mechanism of action based on PGPR, seaweed extract, and humic acid, this product not only increases bulb weight by 15–25% but also extends storage life by up to 30%. For Brebes farmers who want to transition to sustainable agriculture without sacrificing yields, biofertilizer is the right choice. Get more information or consult your needs via Biosolution WhatsApp. See the products POC Bulb Quality Formula and Complete Liquid Biofertilizer Formula for optimal harvest results.