Plasmodiophora brassicae

Fungal Disease

Clubroot is a serious disease affecting cruciferous crops, caused by the soil-borne pathogen Plasmodiophora brassicae. It leads to gall formation on plant roots, impacting water and nutrient absorption.

Symptoms:

Formation of galls or swollen structures on roots

Wilting of plants under warm conditions

Stunted growth and yellowing of leaves

Check for root galls by uprooting suspected plants

Pathogen Characteristics:

Plasmodiophora brassicae is a soil-borne pathogen. Thrives in cool, moist environments. Can persist in soil and water for many years

Environmental Conditions Favoring Disease:

Temperature:

Optimal range: 20 to 26°C

Reduced infection below 17°C

Inhibited activity at extremely high temperatures

Moisture:Requires high humidity and moist soil for infection and sporulation

Soil pH:Prefers low soil pH, which increases pathogen activity

Management Tips:

1. Soil pH Adjustment: Apply lime to raise soil pH to above 7.0.

2. Crop Rotation: Rotate with non-host crops to reduce pathogen build-up.

3. Soil Drainage: Improve soil drainage to reduce moisture levels.

4. Hygiene: Remove and dispose of infected plants to prevent spread.

5. Resistant Varieties: Use clubroot-resistant cultivars where available.

Note: Ensure accurate diagnosis, as root-knot nematodes can cause similar galls on roots. Proper identification is key to effective management.