Symptoms of Powdery Mildew of Pea are first appear on___

🔑Key Points
Powdery mildew is caused by a group of related fungi in the Erysiphaceae family. 
Causal organism – Erysiphe polygoni
Symptoms:
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.
Light brown spots also appear on the leaves of the plant.
The spots first form as small colourless stigmas or spots and a thin layer is spread later around the leaves.
When the disease develops, white-coloured powder accumulates on its leaves due to which plants stop the process of photosynthesis and the growth of plants stops.
When the disease is severe, the peas are stunted, turn yellow, and defoliate.
Due to this disease, the plants remain small & less pod formation.