BLACKGRAM :: MAJOR DISEASES:: LEAFSPOT

BLACKGRAM :: MAJOR DISEASES:: LEAFSPOT

Leaf spot - Cercospora canescens
Symptoms

Small, circular spots develop on the leaves with grey centre and brown margin. Several spots coalesce to form brown irregular lesions. In severe cases defoliation occurs. The brown lesions may be seen on petioles and stem in severe cases. Powdery growth of the fungus may be seen on the centre of the spots


Cercospora canescens

Pathogen
The fungus produces clusters of dark brown septate conidiophores. The conidia are linear, hyaline, thin walled and 5-6 septate.
Favourable Conditions

Humid weather and dense plant population.

Disease cycle
The fungus survives on diseased plant debris and on seeds. The secondary spread is by air-borne conidia.
Management

Remove and burn infected plant debris.
Spray Mancozeb at 2 kg/ha or Carbendazim at500 g/ha.