Wart disease (potato)
Rough, cauliflower-like warty growths on the tuber, mainly around the eyes — a soil-borne quarantine fungus whose spores can survive in soil for decades.
- Pathogen
- Synchytrium endobioticum (soil fungus)
- Spreads by
- Infected soil, tubers, tools & manure
- Favoured by
- Cool, moist soil; infected planting stock
- Main risk
- Unsellable warty tubers; decades-long soil infection
Overview
Wart disease of potato is caused by the fungus Synchytrium endobioticum, which raises rough, cauliflower-like warty growths (galls) on the tuber, mainly around the eyes — sometimes as large as the tuber itself. Similar warty galls can appear on the stem base and stolons near the soil line. Galls start creamy-white and turn brown-black and rot as they age, and affected tubers are unfit for sale or table use.
The fungus lives in the soil as extremely long-lived resting spores that can stay infective for 20-40 years, and spreads through infected seed tubers, contaminated soil clinging to tools, footwear or manure, and irrigation water carrying infected soil. Because of this, wart is treated as a notified, quarantine disease in India rather than an ordinary field problem — once confirmed in a field, containment is handled at the regulatory level, and the most reliable control for growers is planting a wart-resistant variety and never moving soil, tubers or tools out of an affected field.
How to identify it
- Rough, cauliflower-like warty growths (galls) on the tuber, mainly around the eyes — sometimes as large as the tuber itself.
- Similar warty galls can appear on the stem base, stolons and sometimes leaf axils near the soil line.
- Galls start creamy-white and turn brown-black and rot as they age; the plant often shows little above-ground symptom otherwise.
- Affected tubers are unfit for sale or table use; a heavily infected field can lose much of its saleable crop.
What causes it and when
- Caused by the fungus Synchytrium endobioticum, which lives in the soil as extremely long-lived resting spores.
- Spreads through infected seed tubers, soil clinging to tools, footwear or manure, and irrigation water carrying infected soil.
- Favoured by cool, moist soil conditions.
- It is a quarantine (notified) disease in India — once a field is confirmed infected, its soil can stay infective for 20-40 years, so it is treated as a regulatory problem, not just a field one.
Cultural & organic control
- Grow a wart-resistant/immune variety if you are in or near a known-affected area — several released Indian varieties carry this trait; check current options with your KVK or state horticulture department.
- Never bring seed tubers, soil or manure from a wart-affected area into a clean field.
- If wart is confirmed in your field, do not move soil, tubers, farm tools or vehicles from it to any other field without cleaning them thoroughly.
- Report suspected wart symptoms to your local agriculture department — containment is handled at the area level, not just the farm level.
Chemical / seed treatment
- There is no practical chemical cure for wart disease once soil is infested — fungicides do not clear the resting spores from soil.
- Management rests on resistant varieties and strict quarantine of infected soil/tubers, not on spraying.
- Regulatory authorities may advise a long rotation away from potato (many years) in a confirmed-infected field, alongside resistant varieties where potato must still be grown.
- Follow your state agriculture department's specific containment protocol if your field is confirmed positive — this is not a do-it-yourself spray decision.
Prevent it coming back
- Always source seed tubers from a certified, wart-free supplier, never from a known-affected pocket.
- Grow resistant/immune varieties as routine practice in or near any area with a wart history.
- Keep soil, tools and vehicles from an infected field away from clean fields at all times.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Varieties to consider
Named seed varieties whose resistance or susceptibility to this problem is documented on their own variety page.
Frequently asked questions
My potato tubers have rough, cauliflower-like growths near the eyes — what is this?
This is likely wart disease (Synchytrium endobioticum), a soil-borne quarantine fungus. Affected tubers are unfit for sale, and the fungus's spores can survive in soil for decades once a field is infected. It is a notified disease in India, so report suspected symptoms to your local agriculture department rather than treating it as an ordinary field problem.
Can I spray or treat my soil to get rid of wart disease?
No — there is no practical chemical treatment that clears wart disease from soil once it is infested; the resting spores can stay infective for 20-40 years. The real control is growing a wart-resistant variety and strictly not moving soil, tubers or tools out of an infected field into a clean one.
Which potato varieties resist wart disease?
Several released Indian varieties carry resistance or immunity to wart disease — Kufri Jyoti, Kufri Pukhraj and Kufri Bahar are all noted as immune on our variety pages. Confirm the current recommended resistant varieties for your area with your local KVK, especially if you farm in or near a known wart-affected pocket.
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.