How to diagnose and correct micronutrient deficiency

Find the problem before you spray: observe where and how the symptom appears, rule out pests, disease and water, and confirm with a soil or leaf test. Then correct the cause, choose soil, foliar or seed treatment as the situation needs, apply at the right stage, and build soil organic matter so the shortage does not keep coming back.

By Gafar Laiya and the Gujarat Bio Organics team. Updated November 2026.

Step 1: observe

• Note which leaves show it, the pattern and colour.
• Note where in the field: patches, low spots, edges, or everywhere.
• Note the stage of the crop and recent weather, irrigation, fertilizer and sprays.
• Use the symptom guide.

Step 2: rule out other causes

• Check for pests and disease on both sides of the leaves and on the roots.
• Check drainage and soil moisture.
• Ask whether a herbicide or spray could have drifted.

Step 3: test

• Get a soil test before the season; the Soil Health Card scheme tests sulphur, zinc, iron, manganese, copper and boron.
• Use a leaf test for orchards and high-value crops.
• See how to take a soil sample.

Step 4: fix the cause

• Correct drainage and over-irrigation.
• Correct soil pH: lime for acid soils, gypsum for sodic soils, organic matter for all.
• Balance phosphorus, potash and nitrogen to the soil test.

Step 5: choose the method

Step 6: time it right

• Before or at sowing for soil application.
• Before flowering for boron and zinc in fruit crops.
• At early symptoms on new growth for foliar sprays.
• Avoid spraying in hot midday sun.

Step 7: apply safely

• Take the dose from the soil test report, the label or your agriculture officer.
• Never double a dose; boron, copper, nickel and cobalt are harmful in excess.
• Do a jar test before mixing products in one tank.
• Do not mix zinc sulphate with phosphate fertilizers in one bag.

Step 8: build the soil

• Add farmyard manure, compost or green manure every season.
• Return crop residues instead of burning them.
• Rotate crops, including legumes.
• Keep records and test every two to three years.

Doses depend on the crop, soil and product, so this page gives methods, not amounts. Take the dose from your soil test report, the product label or your local agriculture officer or KVK. Results differ from farm to farm with soil, weather, crop and management. Farmer experiences on this site are their own reports, not a promise of results.