Boron 20% – Uses, Dosage & Application

Boron 20% is a straight micronutrient fertilizer registered under India's Fertilizer (Control) Order, 1985 (FCO). It supplies boron in a water-soluble form for soil and foliar application. Since fertilizers fall under the FCO rather than the Central Insecticides Board (CIB), the crop, symptom and dosage information on this page is drawn from agricultural-university (PAU/ICAR-aligned) package-of-practices guidance on boron deficiency management, along with the product's own FCO label application rate.

Which Deficiency Symptom Is This For? (Symptom Guide)

Boron deficiency is common on light, sandy and calcareous soils, especially after heavy rain or irrigation leaches boron out of the root zone. It affects growing points and reproductive structures first. The table below lists crops where this deficiency is typically seen and its field symptoms.

Mode of Action

Boron is required for the synthesis and stability of plant cell walls and membranes, and it plays a central role in pollen tube growth, flower and fruit set, and the movement of sugars from leaves to developing reproductive structures. Because boron is largely immobile within the plant once absorbed, deficiency symptoms appear first and most severely at growing points, flowers and young fruit/curd tissue rather than on older leaves. This is why boron deficiency causes distinctive structural disorders — hollow stems, cracked petioles, and heavy flower/boll shedding — rather than simple leaf yellowing.

Features & Benefits

• Corrects boron deficiency responsible for hollow stem and brown curd in cauliflower, boll/flower shedding in cotton, and sterility in wheat and mustard.
• Supports pollen viability, flower retention and fruit/seed set across a wide range of crops.
• Improves cell wall strength, reducing stem cracking and hollowing.
• Water-soluble form suitable for both basal soil application and corrective foliar spray.
• A single, targeted application at the right growth stage (flowering/curd initiation) is often enough to prevent yield loss from boron deficiency.
• Complements general NPK and other micronutrient fertilizer programmes on boron-deficient soils.

Recommended Usage

Most agricultural-university boron recommendations for micronutrient correction are given as a soil (basal) rate per hectare or as a percentage foliar-spray concentration rather than a fixed per-acre figure; both formats are shown below.

Where the source recommendation is given per hectare (e.g. 20 kg borax/ha for cauliflower, 5–10 kg borax/ha as a general basal rate), the per-acre figure shown is derived using 1 hectare ≈ 2.47 acres. Foliar rates are given directly as a percentage solution, since this is how boron corrective sprays are conventionally recommended — mix the stated percentage (e.g. 0.2% = 2 g per litre of water) and spray to the point of leaf run-off. Basal rates are based on agricultural-university package-of-practices guidance for boron-deficient soils; confirm with a soil test and your local agricultural extension office before repeat applications, since excess boron can be toxic to crops.

How to Use

1. Confirm boron deficiency before use — look for hollow stems, flower/boll shedding or poor grain set, and where possible confirm with a soil test, since the gap between deficient and toxic boron levels is narrow.
2. For basal soil application, broadcast the required quantity evenly and incorporate into the soil before sowing or transplanting; do not place in direct contact with seed.
3. For foliar correction, dissolve the required quantity completely in the specified water volume and spray using a knapsack or power sprayer with a fine nozzle for even coverage.
4. Time foliar sprays to precede the sensitive stage — pre-flowering or curd/boll initiation — since boron mainly protects the current reproductive structures rather than correcting long-standing damage.
5. Apply during the cooler part of the day (early morning or evening) to reduce evaporation and leaf scorch risk.
6. Do not repeat basal doses every season without a fresh soil test — boron toxicity from repeated over-application can damage crops and reduce yield.

Precautions & Safety

• Wear gloves and a mask while handling, mixing and applying, as a routine precaution for any fertilizer input.
• Do not exceed the recommended dose or concentration — boron has a narrow safety margin between deficiency and toxicity for most crops.
• Avoid foliar spraying during peak heat, bright sunshine or before rain.
• Keep away from direct contact with eyes and skin; wash immediately with water if contact occurs.
• Store in the original, tightly closed pack in a cool, dry place away from moisture, and out of reach of children and livestock.
• Wash hands, face and any exposed skin thoroughly with soap and water after handling or spraying.

Brand names mentioned on this page are registered trademarks of their respective owners and are referenced here for identification purposes only; FarmMate is not affiliated with or endorsed by these brands. This page is for general information only — always consult your local agricultural extension office and confirm the current product label before use.