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Agricultural crops :: Cash crops :: Cotton

Alterneria leaf blight: Alternaria macrospora


  • The disease may occur in all stages but more severe when plants are 45-60 days old.
  • Small, plate to brown, irregular or round spots, may appear on the leaves.
  • Each spot has a central lesion surrounded by concentric rings.
  • Several spots coalesce together to form blighted areas.
  • The affected leaves become brittle and fall off.
  • Sometimes stem lesions are also seen.
  • In severe cases, the spots may appear on bracts and bolls.


  • Remove and destroy the infected plant residues.
  • Spray Mancozeb or Copper oxychloride at 2kg/ha at the intimation of the disease.
  • Two to three sprays may be given at 15 days interval. 

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