- 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).
Pacific Pests, Pathogens, Weeds & Pesticides
Rice blast (252)
Magnaporthe oryzae. Previously, Magnaporthe grisea. Pyricularia oryzae is the asexual name.
AUTHOR Grahame Jackson
Information from BugwoodWiki (2014) Magnaporthe oryzae. (https://wiki.bugwood.org/Magnaporthe_oryzae); and Blast (various articles). Rice Knowledge Bank. IRRI. (http://www.knowledgebank.irri.org/search-results?gsquery=blast); and Meng Q et al. (2019) Proteomics of rice - Magnaporthe oryzae interaction: what have we learned so far? Front. Plant Sci 29. (https://www.frontiersin.org/articles/10.3389/fpls.2019.01383/full); and (with Photo 2) CABI Magnaporthe oryzae (rice blast disease) (2019) Invasive Species Compendium. (https://www.cabi.org/isc/datasheet/46103): and from TeBeest DOC (2012) Rice blast. The Health Instructor. (https://www.apsnet.org/edcenter/disandpath/fungalasco/pdlessons/Pages/RiceBlast.aspx). 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.