Name of Disease: Brown spot.
Cause: Cochliobolus miyabeanus (Ito & kur.) Drech ex Dast.
Helminthosporium oryzae (Breda de Haan.)
Symptoms: Typical symptom is the development of innumerable, dark, brown, elliptical spots on the leaves, stems and glumes. In severe cases these spots may coalesce and cover the entire leaf. Inflorescence in a mature plant becomes distorted. The grains fail to form. In case of early and severe infection the head may fail to emerge from the sheath and perish without developing and discoloured. Entire leaf may become brown and dry out in heavy infection.
1. Seed treatment with Agrosan G.N. or Ceresan or Thiram @ 2.5g/kg of seed.
2. Add Muriate of Potash to correct the potash deficiency in soil. Apply balanced does spraying of NPK fertilizers.
3. Give three to four spraying of Dithane Z-78 or Dithane M-45 (2.5 g/l) at 10-12 days interval just before the appearance of initial symptoms of the disease.
4. Do not select seeds from the diseased field and plants.
5. Grow moderately resistant varieties like sabarmati etc.