Alternaria Blight Management in Rapeseed and Mustard

Causal organism: Alternaria brassicae

Symptoms:

1. The pathogen perpetuates through seed and affected plant portion (refuse) in the soil.
2. Appearance of concentric black spots on leaves, stem and pods.
3. During severe outbreak, pods turn black in colour and may also rot. Such pods contain shriveled, undersized seeds.

Control Measures:

• Use of healthy seeds for sowing should be preferred.
• Spray Mancozeb 75 WP at the rate of 2 kg in 1000 litres of water per hectare at 10 days interval as soon as the symptoms start appearing on the plants.
• Collect and burn the affected plant portions after the harvest of the crop.