• The infection of the foliage results in yellow ‘V’ shaped spots arising along the margin which extend in the direction of the midrib.
• These spots are associated with a typical black discoloration of the veins.
• The infection extends through the xylem to the stalk and the vascular bundles turn black. In severe infection, the whole leaf shows discoloration and eventually falls off.

Management

• Seed treatment with Aureomycin 1000ppm for 30 min is effective in killing both the internally and externally seed-borne pathogen.
• Drenching the nursery soil with formaldehyde 0.5% helps in checking the disease.
• Application of bleaching powder at 10.0 to 12.5 kg/ha controls the disease.