Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Rice bacterial leaf blight (418)

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  • Widespread. Asia, Africa, North, South, Central America, Europe, Oceania. In Australia, Fiji.
  • Important disease of rice, causing regular epidemics. Wild grasses are hosts.
  • Bacteria enter natural openings and wounds, moving in water conducting tissues, causing streaks with wavy margins – yellowish-white (seedlings), pale yellow (older plants) - joining together, resulting in wilts, drying and death. Droplets ooze from streaks leaving crusts. Spread with irrigation water, wind and rain, possibly seed. Survival in seed, and weeds.
  • Biosecurity: import only bacteria-free certified seed, and subject to closed quarantine.
  • Cultural control: use certified seed, or select seed from healthy plants; do not clip seedling leaves; do not apply excessive N; ensure good drainage (flooding allows infection); weed (especially Leersia species); plough stubble after harvest; fallow fields to destroy bacteria; use resistant varieties - available in Africa and Asia.
  • Chemical control: not effective for this disease.
Common Name

Rice bacterial leaf blight; also known as rice leaf blight.

Scientific Name

Xanthomonas oryzae pv. oryzae. Different strains exist in Japan and the Philippines and, importantly, differences exist between strains in Asia and Africa.

AUTHOR Grahame Jackson
Information from CABI (undated) Rice leaf blight (Xanthomonas oryzae pv. oryzae). Plantwise Knowledge Bank. (; and CABI (2018) Xanthomonas oryzae pv. oryzae (rice leaf blight). Crop Protection Compendium. (; and Bacterial blight (various articles). Rice Knowledge Bank. IRRI. (; and from Xanthomonas oryzae pv. oryzae. Wikipedia. ( Photo 1 Chin Khoon, CABI. Photo 2-4 Rice Knowledge Bank. IRRI. (

Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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