Correcting Zinc Deficiency in Paddy: A Field Guide

Zinc deficiency is among the most common — and most frequently misdiagnosed — nutritional disorders in transplanted paddy. Because early symptoms resemble general stunting or discoloration, many farmers mistake it for a disease or simply attribute it to weather stress, delaying correction until yield loss has already set in.

The classic symptom pattern starts around 2–3 weeks after transplanting: interveinal chlorosis on the lower and middle leaves, followed by bronzing and stunted tillering. In severe cases, plants show a distinct 'khaira' disease appearance with brown blotches on leaves — a term many paddy-growing regions use specifically for zinc-deficiency-driven symptoms.

Soils with high pH, high phosphorus application history, or heavy waterlogging are particularly prone to zinc lock-up, making the nutrient unavailable to roots even when present in the soil. This is why a soil test showing 'adequate' zinc doesn't always translate to what the crop can actually absorb.

Correction is most effective when chelated Zinc (such as Zinc EDTA) is applied at the early tillering stage, either as a soil application at transplanting or a foliar spray once symptoms appear. Chelated forms remain plant-available even in higher pH soils, unlike zinc sulphate, which can bind quickly to soil particles. A single well-timed correction is typically enough to recover most of the yield potential lost to early-stage deficiency — but waiting until the boot-leaf stage significantly reduces how much recovery is possible.