• Bangle blight or bangili
• Leaf- turns bronze colour, shrivel and die
• Vascular system of stem, root, stolon and tuber turns brown
• Ring disease - brown ring in the tuber due to discolouration of vascular bundles
• Whitish bacterial exudate oozes from the vascular system of cut stems and cut tubers

• Gram –ve, rod shaped bacteria, polar flagellum
• Forms no spores and capsules

Mode of spread and survival :

• Infected soil and seed tubers - source of infection
• Decay plant parts release masses of bacteria in the soil - viable from season to season
• Infection through wounds in roots which spread through vascular system into the stem

Epidemiology :

• Soil temp - 25 to 35°C
• RH - 50%
• Optimum pH - 6.2 to 6.6

• Crop rotation - potato-wheat
• High degree of resistance - clones of Solanum phureja