Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Rice blast (252)

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  • Worldwide distribution. On rice and wild grasses. An important disease.
  • Spots oval or diamond-shaped, 5-15 mm, with whitish-grey centres and dark brown borders, merging, killing the leaves. Rots of leaf sheath, stem and panicles. Plants killed until tillering stage.
  • Spread of spores in irrigation water and by wind.
  • Cultural control: sow to avoid flowering at wettest times; avoid overlapping crops; split N applications; space plants to maximise air flow; collect and burn trash after harvest. Use chemicals at heading stage.
  • Chemical control: Seed/field treatment: mancozeb, captan (protectants); azoles, strobilurins (eradicants).
Common Name

Rice blast

Scientific Name

Magnaporthe oryzae. Previously, Magnaporthe grisea. Pyricularia oryzae is the asexual name.

AUTHOR Grahame Jackson
Information from BugwoodWiki (2014) Magnaporthe oryzae. (; and Blast (various articles). Rice Knowledge Bank. IRRI. (; and Meng Q et al. (2019) Proteomics of rice - Magnaporthe oryzae interaction: what have we learned so far? Front. Plant Sci 29. (; and (with Photo 2) CABI Magnaporthe oryzae (rice blast disease) (2019) Invasive Species Compendium. ( and from TeBeest DOC (2012) Rice blast. The Health Instructor. ( Photo 1 IRRI Rice Knowledge Bank.

Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.

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