Disease - Powdery mildew
Causal organism - Erysiphe polygoni
Symptoms - Powdery mildew is a fungal disease of worldwide occurrence. The leaves are affected first by this disease and later on the stems and pods are also affected.
White powdery spots are formed on both the surface of the leaves. Due to this disease, light brown spots appear on the leaves of the plant.
The spots first form as small colorless stigmas or spots, but later, a thin layer is spread around the leaves.
When disease develops, white colored powder accumulates on its leaves. Due to which plants stop the process of photosynthesis and the growth of plants stops.
Damage - The occurrence of this disease is constantly being watched, so it is considered more destructive.
This disease is worst in dry weather. Due to this disease, the plants remain small & less pod formation.
Control - To prevent this disease, seeds should be sown after treated with Bavistin initially. In case of disease in standing crop, appropriate amount of soluble sulphur should be sprayed on the plants.
When symptoms of the disease are seen, sulphur powder at the rate of 25 to 30 kg per hectare should be dredge up.
Integrated Disease Management (I.D.M.) - Diseased plants should be uprooted and destroyed.
Use disease resistant varieties.