TNAU Agritech Portal
Home | About Us | Success Stories | Farmers Association | Farmers' Innovation | Publications | Contact
Agricultural crops :: Cash crops :: Cotton

Grey or Areolate mildew : Ramularia areola


  • Irregular to angular pale translucent lesions bound by veinlets and grey powdery growth appear on lower surface of leaf
  • Correspondingly light green specks appear on the upper surface of leaves.
  • In severe cases whitish grey powdery growth appear on upper surface. The affected leaves dry up inward, turn yellow and fall prematurely.
Survival and Mode of Spread
  • The pathogen survives during summer in the infected crop residues. The perennial cotton plants and self-sown cotton plants also harbour the pathogen.
  • Primary spread is through conidia from infected plant debris.
  • Secondary spread is through wind, rain splash, irrigation water and implements.
Favourable Conditions
  • Wet humid conditions during winter cotton season
  • Intermittent rains during North-East monsoon season
  • Low temperature (20-30 0C) during October-January
  • Close planting
  • Excessive application of nitrogenous fertilizers
  • Very early sowing or very late sowing of cotton
  • Remove and burn the infected crop residues.
  • Remove the self-sown cotton plants during summer months.
  • Avoid excessive application of nitrogenous fertilizers/manures.
  • Adopt correct spacing based on soil conditions and varieties.
  • Spray Wettable sulphur @ 400 g /acre or Chlorothalonil@ 200 g / acre or Difenaconazole @ 100 ml or Kresoxim Methyl @ 200 ml/ acre or Tebuconazole @ 200 ml/ acre or Propiconazole @ 200 ml/acre or Metiram 55% + Pyraclostrobin 5% WG @ 200g/ acre or Azoxystrobin 18.2% + Difenoconazole 11.4% w/w SC 200ml/ acre at 60, 90 and 120 days after sowing.
Source of Information
  • Online resources
  • CPG 2020

Whitesh grey powdery growth

Updated on Apr 2023

Home | About Us | Success Stories | Farmers Association | Publications | Disclaimer | Contact Us

TNAU. All Rights Reserved © 2008 - 2023.