Sterility Mosaic Disease of Pigeonpea Control

Symptoms

Affected plants show a light and dark green mosaic mottling and ringspots on leaves, much smaller pale leaves, and excessive bushy vegetative growth giving a dense green appearance. The most striking sign is partial to complete failure of flowering, so the plant sets few or no pods and looks green and healthy but is sterile. Symptoms often appear on one branch first and then spread.

Damage

Sterility mosaic is a major disease of pigeonpea in the Indian subcontinent and can cause yield losses up to 100 percent because affected plants flower poorly or not at all. It is called the green plague of pigeonpea because diseased plants stay green and bushy but produce no grain. Early infection before flowering causes the heaviest loss.

Organic & cultural control

The virus is spread by a microscopic eriophyid mite, not by seed or sap, so management targets the mite and the sources. Rogue out and destroy infected plants early, including self-sown and ratoon pigeonpea that carry the disease between seasons. Avoid planting near old infected pigeonpea fields. Maintain a gap between successive pigeonpea crops to break the green bridge for the mite. Conserve predatory mites and natural enemies.

Chemical control

There is no cure for the virus, so chemicals are used only to reduce the eriophyid mite that spreads it. A recommended acaricide or wettable sulphur may be sprayed to lower mite numbers in nurseries and young crops where pressure is high. Removing infected plants matters more than spraying. Always follow the product label for dose and pre-harvest interval and consult your KVK or an agronomist before use.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Grow resistant or tolerant pigeonpea varieties recommended for your region as this is the best protection against sterility mosaic. Use clean fields away from old infected pigeonpea and destroy ratoon and volunteer plants. Sow at the recommended time so the crop is not young and tender when mite populations peak. Rogue infected plants regularly and keep a rotation gap.