Causal Agent: 

Fungus (Plasmodiophora brassicae)

Characteristic Symptoms:

Common symptoms are swelling and injury of roots and hypocotyl

The pathogen infects taproots and secondary roots
Roots of infected plants  form galls which varies with plant age and root morphology and eventually result to root clubbing
Plants becomes yellow and stunted due to root clubbing and eventually wilt
Infected plants have fewer, smaller and blue-green leaves.
Conditions for Disease Development
The disease is favoured by high soil moisture, soil temperature at above 20° C and soil acidity
Contaminated transplants are the primary way of long -range spread
The pathogen can survive dormant in soil  for decades and can be spread by irrigation water, infested roots and wind-borne soil particles
Management and Control:
Use of  resistant variety (if available)
Use pathogen-free transplants.
Avoid acidic soil.
Crop rotation with non-host crop for at least 3 years to reduce the amount of primary inoculum.
Increase  soil pH  to above 7.0 by lime application to reduce symptom severity or root clubbing.
Calcium and Boron application can also reduce root clubbing.
Avoid furrow irrigation.

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