e course

GREEN GRAM ::MAJOR DISEASE :: ANTHRACNOSE

 


 

 

Anthracnose - Colletotrichum lindemuthianum - (Sexual stage: Glomerella lindemuthianum)
Symptoms
            The disease appears on all aerial part parts and at any stage of plant growth. Circular, black, sunken spots with dark center and bright red orange margins on leaves and pods. In severe infections, the affected parts wither off. Seedlings get blighted due to infection soon after seed germination.
Pathogen
The Disease appears on fungus mycelium is septate, hyaline and branched. Conidia are produced in acervuli, arise from the stroma beneath the epidermis and later rupture to become erumpent. A few dark coloured, septate setae are seen in the acervulus. The conidiophores are hyaline and short and bear oblong or cylindrical, hyaline, thinwalled, single celled conidia with oil globules. The perfect stage of the fungus produces perithecia with limited number of asci, which contain typically 8 ascospores which are one or two celled with a central oil globule.
Favourable Conditions

  • The disease is more sever in cool and wet seasons.

Disease cycle
The fungus is seed-borne and cause primary infection. It also lives in the infected plant tissues in soil. The secondary spread by air borne conidia produced on infected plant parts. Rain splash also helps in dissemination.
Management

  • Hot water treatment at 54º for 10 min.
  • Use disease free seed.
  • Follow crop rotation
  • Remove and destroy infected plant debris in soil.
  • Treat the seeds with Carbendazim at 2 g/kg.
  • Spray Carbendazim 500g or Mancozeb 2kg/ha soon after the appearance of disease and repeat after 15 days.