RED GRAM :: MAJOR DISEASE :: POWDERY MILDEW

RED GRAM :: MAJOR DISEASE :: POWDERY MILDEW

Powdery mildew - Leveillula taurica
Symptoms
White powdery growth of the fungus can be seen on the lower surface of leaves. The corresponding areas in upper surface show pale yellow discoloration. The white powdery mass consists of conidiophores and conidia of the fungus. In severe cases, the white growth can be seen on the upper surface also. The severe infection of the fungus leads to premature shedding of leaves and plant remains barren.


Leveillula taurica	Cercospora indica	Leveillula taurica

Pathogen
The fungus is intercellular and absorbs nutrition through haustoria. The conidiophores, which arise through stomata, are hyaline, long, non septate, slender and rarely branched and bear single conidium at the tip. The conidia are hyaline, single celled and elliptical or clavate. The fungus also produces black, globose cleistothecia with simple myceloid appendages. They contain 9-20 cylindrical asci. Each ascus contains 3-5 ascospores which are also hyaline and unicellular.


Leveillula taurica - Conidia and conidiophores	Leveillula taurica - Cleistothecium

Favourable Conditions

Dry humid weather following rainfall.

Disease Cycle
The fungus survives in the soil through cleistothecia and ascospores from asci infect the first lower most leaves near the soil level. Secondary spread is by air-borne conidia.
Management
Spray Carbendazim 500g/ha or Wettable sulphur 2 kg/ha at the initiation of the disease and repeat after 15 days.