Common Crop Diseases in India and How to Identify Them

Blights, including early and late blight, show up as brown or black spots on the leaves that spread quickly, especially in humid weather. They are common in tomato and potato. Late blight in particular can devastate a crop in just a few days, so it demands immediate action.

Rusts appear as orange, brown or yellow powdery pustules on the leaves. Yellow rust in wheat is a well-known example. Rusts are favoured by cool, moist conditions and can spread rapidly across a field, so regular scouting and resistant varieties are key.

A wilt makes plants droop and die even though the soil is moist — a sign the problem is in the roots or stem, not the water supply. Wilts are soil-borne fungal or bacterial diseases common in tomato, brinjal, cotton and pulses. Crop rotation and resistant varieties are the main defences.

Viral diseases like leaf curl show as curled, crinkled, yellowing leaves and stunted plants, common in chilli and tomato. Viruses are spread by insects such as whitefly and thrips, so controlling the insect is the way to control the disease — there is no cure once a plant is infected.

Powdery mildew appears as a white powdery coating on the leaf surface, while downy mildew shows yellow patches on top with fuzzy growth underneath; both are common in cucurbits. Fruit rots such as anthracnose cause sunken dark spots on the fruit in humid weather.

Look closely at leaf tops and undersides, stems and fruit. Note the pattern: spreading spots suggest fungal blight or rust, curling leaves suggest a virus, and sudden wilting despite moist soil suggests a soil-borne disease. Act early by removing infected parts, improving airflow and drainage, and treating at the first symptom. When you are unsure, a clear photo compared against known symptoms — or a diagnosis app — can confirm the problem quickly.