- The disease appears as fine watery translucent streaks 0.5 to 5 mm long initially confined to the portion in between the veins.
- Yellow halo is noticed around the lesions in susceptible varieties.
- Towards the later phase of the disease, the entire leaves turn yellow in colour which closely resembles the symptoms of bacterial leaf blight. Bacteria exuding from the leaves may dry up to form beads.
- The symptoms of BLS looks similar to that of narrow brown leaf spot caused by Cercospora, at later stage when the streaks coalese the symptoms resemble that of BLB. However, this can be distinguished by its inner translucent lesions with yellow bacterial ooze.
Ooze test is a simple method to identify the disease.Mark 4 one square meter plots randomly in the field. From each square meter select five hills at random. Conduct ooze test to confirm the incidence and workout the % of plants affected.
2- 5 % Light to moderate