Clubroot

fungus

Plasmodiophora brassicae

Soilborne slime mold causing grotesque root swelling in brassicas. Extremely persistent in soil.

Identification

Swollen, distorted, club-shaped roots. Wilting in heat despite moist soil. Stunted, off-color plants.

Swollen roots that cannot absorb water/nutrients. Wilting. Stunting. Crop failure. Resting spores persist 20+ years.

Raise soil pH to 7.2+ with lime. No effective organic treatment. Remove and destroy infected plants.

Fluazinam preplant treatment (limited availability). Calcium cyanamide.

Raise pH above 7.2. 7+ year rotation for brassicas. Resistant varieties. Do not transplant from infested soil. Clean boots and tools.

Data confidence: medium | Source: curated_ipm