Bacterial leaf streak
(Xanthomonas oryzae pv. Oryzicola)

  • Initially, small, dark-green and water-soaked streaks on interveins from tillering to booting stage
  • The progress of the streaks is longitudinal, limited by the veins and soon turn yellow or orange brown.
  • All along the streaks bacterial exudates could be observed as tiny yellow or amber colored droplets.
  • These streaks may coalesce to form large patches and cover the entire leaf surface.
  • Lesions turn brown to greyish white then dry when disease is severe
  • Infection in the florets and seeds results in brown or black discoloration and death of ovary, stamens and endosperm and browning of glumes.
Brown to greyish longitudinal streaks on leaves 2-grains transformed into a mass of yellow fruiting bodies
Brown to Greyish
Longitudinal Streaks on
Lesions turn brown to greyish and drying of leaves


  Identification of pathogen
cells of Xanthomonas oryzae pv exudate of Xanthomonas campestris pv. oryzicola
  • The bacteria causing the disease X. oryzae pv.oryzicola occur as rods.
  • The bacteria have no spores and no capsules.
  • They move with the aid of a single polar flagellum.
  • They are Gram-negative and aerobic and can grow favorably at 28 °C.
  • The bacterial colonies on nutrient agar are pale yellow, circular, smooth, convex, and viscid and have an entire margin.

Factors favoring disease development

  • Presence of the bacteria on leaves and in the water or those surviving in the debris left after harvest
  • Warm temperature and high humidity
  • Early stage of planting from maximum tillering to panicle initiation
Cells of Xanthomonas
Oryzae pv
Exudate of Xanthomonas
Campestris pv. Oryzicola


Management Strategies  
  • The disease can be controlled by proper application of fertilizers and proper plant spacing, use of resistant varieties, and hot water treated seeds.
  • Practicing field sanitation is important.
  • Ratoons, straws and volunteer seedlings left after harvest can be destroyed to minimize the initial inoculum at the beginning of the season.
  • Providing good drainage system especially in seedbeds can also manage this disease.
  • Planting of resistant varieties (IR 20, TKM 6) is the most effective method of controlling bacterial leaf streak.
  • Grow nurseries preferably in isolated upland conditions
  • Avoid clipping of seedlings during transplanting.
  • Spray fresh cowdung water extract or lemon grass or mint extract at 20 %.
  • Spraying streptomycin sulphate and tetracycline combination 300g +copper oxychloride 1.25 kg/ha.

Practice Field Sanitation Resistant Variety- IR 20
Practice Field Sanitation Resistant Variety- IR 20
Spray Cowdung or Mint or Lemongrass Extract
Spray Cowdung or Mint or
Lemongrass Extract
Spray Streptomycin
Sulphate + Tetracycline