How to Identify Nutrient Deficiencies by Leaf Symptoms

Plants send visual signals when nutrients are short. Catching them early and correcting precisely is far cheaper than a season of slow, silent yield loss.

Reading the pattern

• •Old leaves yellow first → Nitrogen shortage (also Phosphorus, Potassium, Zinc, Magnesium)
• •New leaves yellow first → Iron, Sulphur, Calcium, Boron shortage
• •Yellowing between veins with green veins → Magnesium or Iron
• •Purple/red tinting → Phosphorus shortage

The golden rule

Symptoms on OLD leaves mean the nutrient moves within the plant; symptoms on NEW leaves mean the nutrient does not — it needed to arrive fresh.

Before spraying anything, rule out soil moisture stress, root damage, and disease — they mimic deficiencies. Confirm with a soil or tissue test when symptoms are uniform across the field.