Club root (crucifers)
Roots swollen into large distorted clubs so the plant wilts by day and stunts — a soil disease of acidic, wet crucifer land whose spores last years.
- Pathogen
- Plasmodiophora brassicae (soil organism)
- Spreads by
- Soil, water, tools & infected transplants
- Favoured by
- Acidic, wet/waterlogged, warm soils
- Main risk
- Clubbed roots; wilting, stunting, no head
Overview
Club root, caused by the soil-borne organism Plasmodiophora brassicae, is a serious disease of cabbage, cauliflower and other crucifers. It infects the roots and makes them swell into large, distorted, club- or spindle-shaped galls (very different from the small knots of root-knot nematode). With the roots turned into malformed clubs, the plant cannot take up water and nutrients properly, so it wilts during the heat of the day (recovering at night early on), yellows, stunts, and heads/curds poorly or not at all.
The clubs later rot, releasing enormous numbers of resting spores into the soil that survive for many years — up to a decade or more — so an infested field stays infested for a long time. Club root is strongly favoured by acidic soils, wet/waterlogged conditions and warm soil temperatures, and it is spread in soil, water and on infected transplants and tools. Because the spores are so persistent, management is preventive and long-term: raising soil pH with lime, improving drainage, long rotation, clean transplants and strict sanitation.
How to identify it
- Roots swollen into large, distorted, club- or spindle-shaped galls — quite unlike the small knots of root-knot nematode.
- Plants wilting during the heat of the day (recovering at night early on), yellowing and stunting.
- Poor or no head/curd formation, and patches that expand year to year in the field.
- Later the clubs rot, releasing spores — so the soil becomes heavily infested.
What causes it and when
- The soil-borne organism Plasmodiophora brassicae, whose resting spores survive in the soil for many years (up to a decade or more).
- Strongly favoured by acidic soils, wet/waterlogged conditions and warm soil temperatures.
- Spread in soil, water, and on infected transplants, tools and machinery.
- An infested field stays infested for years, and each crucifer crop revives and multiplies the organism.
Cultural & organic control
- Raise soil pH toward neutral/slightly alkaline with lime, which strongly suppresses club root in acidic soils.
- Improve drainage and avoid waterlogging, since wet soil favours the disease.
- Practise long rotation away from all crucifers (several years) and control cruciferous weeds.
- Use only clean, disease-free transplants; never carry infested soil or transplants into clean fields.
Chemical control
- There is no reliable chemical cure once roots are clubbed — control is preventive (liming, drainage, rotation, clean transplants).
- Where recommended, soil amendments/bio-agents can support management, but cannot rescue an infested crop.
- Raising pH with lime and improving drainage do more than any spray.
- Confirm the current liming and management package for your soil and crop with your local KVK.
Prevent it coming back
- Keep soil pH up with lime and drainage good in crucifer land, and use long rotation.
- Use clean transplants, control cruciferous weeds, and rogue and remove clubbed plants with their soil.
- Clean soil off tools and machinery and never move infested soil/transplants into clean fields.
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 cabbage/cauliflower roots are swollen into big distorted clubs and the plants wilt and stunt. What is it?
Roots swollen into large, distorted, club-shaped galls, with plants wilting in the day and stunting with poor heads, are club root (Plasmodiophora brassicae), a soil disease. Its spores survive for many years, so control is long-term and preventive: raise soil pH with lime, improve drainage, rotate away from all crucifers for several years, use clean transplants, and never carry infested soil into clean fields. There is no cure once roots are clubbed.
How is club root different from root-knot nematode galls?
Both swell the roots, but the galls look different and the causes differ. Club root makes large, distorted, club- or spindle-shaped swellings of the main roots, caused by the soil organism Plasmodiophora on crucifers, and is favoured by acidic, wet soil. Root-knot nematode makes smaller, bead-like knots along the roots of many crops. Club root is managed mainly by liming to raise pH, drainage and long rotation; root-knot by resistant varieties, solarisation and bio-agents. When in doubt, note the crop and the gall shape.
Why does liming the soil help against club root?
Because club root is strongly favoured by acidic soil, and raising the soil pH toward neutral or slightly alkaline with lime makes conditions much less suitable for the organism, sharply reducing the disease. Combined with better drainage (since the organism also loves wet soil), long rotation away from crucifers and clean transplants, liming is one of the most effective tools against club root — far more useful than any spray, since there is no cure once the roots are clubbed.
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.