It looks like anthracnose disease caused by fungus, Colletotrichum orbiculare . The main symptoms are - appearing of jagged lesions near leaf veins. This lesions are dark brown to black in color with ‘shot hole’ appearance. Warm wet weather favors disease infection and spread.
1. Use certified healthy seeds for sowing.
2. Grow available resistant varieties.
3. Follow crop rotation (at least for 3 years).
4. Use drip irrigation instead of sprinklers.
5. Till the crop residue after cropping season.
6. If disease is severe spray fungicides like Mancozeb (2g/lit) or Copper hydroxide (2g/lit).
Posted by: Dr. Ravishankar Narayana
Posted: March 22, 2016