Sterility mosaic (pigeonpea)
A pale mosaic with bushy, small-leaved growth that makes the pigeonpea plant sterile — little or no flowering and no pods.
- Pathogen
- Virus (pigeonpea sterility mosaic virus)
- Spreads by
- Eriophyid mite (Aceria cajani)
- Favoured by
- High mite numbers; infected volunteers/ratoons
- Main risk
- Sterile plants; no flowering or pods
Overview
Sterility mosaic disease (SMD), often called the "green plague" of pigeonpea (arhar), is a serious viral disease spread by the eriophyid mite (Aceria cajani). Affected plants show a light-green to yellow mosaic or mottling on the leaves, along with reduced leaf size, excessive branching and a bushy, pale, stunted appearance. The defining feature is sterility: the plant produces little or no flowers and sets few or no pods, so it stays green and bushy but yields nothing.
The earlier a plant is infected, the more complete the sterility and the greater the loss — an early-infected plant is essentially a total loss, while late infection matters less. The virus is spread by the tiny eriophyid mites moving from plant to plant (and carried on the wind), not by seed. Because the virus cannot be cured, management relies on resistant varieties (the main defence), roguing out infected plants, managing the mite vector, and removing volunteer/ratoon pigeonpea that carries the disease over.
How to identify it
- A light-green to yellow mosaic or mottling on the leaves, with reduced leaf size.
- Excessive branching and a bushy, pale, stunted appearance.
- Sterility — little or no flowering and few or no pods — the defining feature.
- A plant that stays green and bushy but yields nothing; earliest-infected plants are total losses.
What causes it and when
- The pigeonpea sterility mosaic virus, spread by the tiny eriophyid mite (Aceria cajani), not by seed.
- Mites move plant to plant and are carried on the wind, so spread tracks mite numbers.
- Volunteer and ratoon pigeonpea and infected plants carry the virus and mites over between seasons.
- The earlier the infection, the more complete the sterility and the greater the loss.
Cultural & organic control
- Grow SMD-resistant varieties — the main and most effective defence in endemic areas.
- Rogue out and destroy infected plants early, before mites spread the virus from them.
- Remove volunteer and ratoon pigeonpea and infected plants that carry the disease over.
- Avoid a continuous overlap of pigeonpea crops that bridges the mite and virus between seasons.
Chemical (vector) control
- The virus cannot be sprayed — target the eriophyid mite vector to slow spread, especially early in the crop.
- Use a recommended acaricide/miticide for the eriophyid mite where advised, alongside roguing.
- Killing the mite does not cure an already-infected plant, so combine vector control with resistant varieties and roguing.
- Confirm the current mite-management and variety recommendation for your area with your local KVK.
Prevent it coming back
- Base the crop on SMD-resistant varieties and rogue infected plants promptly.
- Remove volunteer/ratoon pigeonpea and infected plants between seasons to cut the virus and mite reservoir.
- Manage the eriophyid mite and avoid a continuous pigeonpea overlap.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
My pigeonpea is bushy and green with a pale mosaic but has no flowers or pods. What is it?
A pale mosaic with small leaves, excessive branching and a bushy, stunted plant that stays green but produces little or no flowers and no pods is sterility mosaic disease (the "green plague" of pigeonpea), a virus spread by the eriophyid mite. It cannot be cured, and early-infected plants are a total loss. Grow an SMD-resistant variety, rogue out infected plants early, manage the mite vector, and remove volunteer/ratoon pigeonpea.
Why is sterility mosaic called the "green plague"?
Because an affected pigeonpea plant stays lush and green and bushy — it does not wilt or obviously die — yet it is sterile and yields nothing, flowering little or not at all and setting no pods. So a field can look green and healthy while producing almost no grain, a hidden but devastating loss. That deceptive green sterility is why it earned the name "green plague", and why resistant varieties and roguing, rather than waiting for obvious damage, are essential.
How does sterility mosaic spread if not by seed?
It is spread by a tiny eriophyid mite (Aceria cajani) that carries the virus from infected to healthy plants as it moves and is blown on the wind — not through the seed. So volunteer and ratoon pigeonpea and infected plants act as reservoirs that keep the virus and mites going between seasons. Control therefore focuses on resistant varieties, roguing infected plants, managing the mite vector, and removing those reservoir plants, rather than on seed treatment.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.