Rust: Puccinia arachidis

Symptoms:

• Reddish brown raised pustules on lower leaf surface
• Severe defoliation

Pathogen:

• Uredospores pedicellate, unicellular, yellow, oval or round and echinulated
• Teliospores two celled and dark brown

Uredospores

Favourable conditions:

• High relative humidity (> 85%)
• Heavy rainfall
• Low temperature (20-25 ⁰C)

Mode of Spread and Survival:

• Survives as uredospores on volunteer plants
• Uredospores spread through wind
• Rainsplash and implements also help in dissemination

Management:

• Avoid monoculturing
• Remove volunteer plants and reservoir hosts
• Spray mancozeb @ 1000 g/ha or chlorothalonil @ 1000 g/ha or wettable sulphur @ 2500 g/ha. If necessary, repeat the spray after 15 days