TNAU Agritech Portal
Home | About Us | Success Stories | Farmers Association | Farmers' Innovation | Publications | Contact

Agricultural crops :: Pulses :: Blackgram

Powdery Mildew: Erysiphe polygoni
Field diagnostic symptoms
  • Powdery spots/patches on leaves, petiole, stem and pods
  • Diseased leaves turn black and finally shed
  • Malformed pods with few ill filled seeds

Powdery mildew infected plants


Causal agent

Erysiphe polygoni
  • Fungus: Oidium type and ectophytic
  • Condiophores - simple, erect, bear chained conidia
  • Conidia - hyaline, thin walled, elliptical/ barrel shaped/ cylindrical and single cell
  • Chasmothecia contain 4-8 asci and each ascus contains 3-8 ascospores
   
Conidiophores and conidia
Survival and mode of spread
  • Survival: Chasmothecia in the infected plant debris
  • Primary spread: Ascospores from perennating chasmothecia
  • Secondary spread: Air-borne conidia
  • Rain splash
Favourable conditions
  • Temperature: 22 to 26°C
  • Warm humid weather
  • Relative humidity: 80 – 88 %
  • Severe during late kharif and rabi seasons
Integrated disease management
  • Remove and destroy infected debris
  • Spray NSKE @ 5% or neem oil @ 3% twice at 10 days interval
  • Spray Eucalyptus leaf extract @ 10% at initiation of disease and 10 days later
  • Spray any one of the following fungicides at initiation of disease and second spray at 15 days later.
    1. Carbendazim 50 WP @500g/ha
      Wettable sulphur 80 WP @ 1500g/ha
      Propiconazole 25% EC @ 500ml/ha
      Azoxystrobin 5.1%w/w +Tebuconazole 9.1% w/w+ Prochloraz 18.2 % w/w EC @ 1250ml/ha
      Captan 70% + Hexaconazole 5% WP @ 750ml/ha
      Sulphur 85% DP @ 15-20 kg/ha

Updated on Jun 2023

Home | About Us | Success Stories | Farmers Association | Farmers' Innovation | Publications | Contact Us

© 2008 - 2023 TNAU. All Rights Reserved.