Grey or Areolate mildew of cotton

Grey or Areolate mildew: Ramularia areola

Symptom:
  • Irregular to angular pale translucent lesions on lower surface, bound by veinlets and grey powdery growth
  • Light green specks on upper surface
  • In severe cases whitish grey powdery growth on the upper surface.  Affected leaves dry up inward, turn yellow and fall prematurely
  • Growing the resistant varieties like Sujatha and Varalakshmi.
Management:
  • Remove and burn the infected crop residues.
  • Rogue out the self-sown cotton plants during summer months.
  • Avoid excessive application of nitrogenous fertilizers/manures.
  • Adopt the correct spacing based on soil conditions and varieties.
  • Spray the crop with Carbendazim at 250-375g or wettable sulphur at 1.25-2.0 kg/ha, repeat after a week.

 

Source-

  • TamilNadu Agritech Portal