Downy Mildew
In Mustard, for the prevention of Downey mildew, do the seed treatment as below.
Plant parts affected
Leaves, Stem, Inflorescence
Initial diagnosis:
Small, creamy to light brown lesions on the underside of the lower leaves
Symptoms:
"Water soaked yellow patches or flecks on upper surface of the leaves. Hypertrophy of the peduncle of inflorescence"
Damage type:
"At seedling stage it causes seedling mortality in patches in the field. Leaves dry up, shrivel and tear off easily. Malformation and swelling of stem Bending and twisting of stalk."
Take a picture of the disease and get a solution