Cultivar · Rice cultivar
IR64
IR64 is a semi-dwarf indica rice released by the International Rice Research Institute (IRRI) in 1985. Valued for its grain quality and broad adaptation, it became one of the most widely grown and widely studied rice varieties in tropical Asia.
Record
Cultivar / variety- Variety of
- Rice
- Botanical taxon
- Oryza sativa (indica group)
- Type
- Inbred line (indica)
- Breeding method
- Cross-breeding (pedigree selection)
- Origin
- Los Baños, Laguna (IRRI), Philippines
- Released
- 1985
- Breeder / institution
- International Rice Research Institute (IRRI)
- Registry status
- Historical
- Registries
- International Rice Research Institute (IRRI) · Global · as of 2026-07-12IR64 is documented in IRRI’s variety history as a widely grown semi-dwarf indica released in 1985. Specific record identifiers are not reproduced here.
- Adaptation
- Irrigated and favourable rainfed lowland tropics
- Intended use
- Staple food grain
Registry listing or variety protection is jurisdiction- and date-specific and does not by itself indicate current commercial availability, universal cultivation approval, patent status, or a recommendation.
IR64 is a semi-dwarf indica rice variety developed at the International Rice Research Institute (IRRI) in the Philippines and released in 1985. It followed earlier IRRI lines such as IR8 and IR36 and was bred to combine good agronomic performance with the long, slender grain and cooking quality preferred in many markets.
IR64 went on to be grown very widely across South and Southeast Asia and became a common benchmark, or check variety, in rice research and breeding. As with any variety, its behaviour in the field depends on local environment and crop management.
Origin and breeding history
IR64 was bred at IRRI, in Los Baños, Philippines, and released in 1985. It descends from IRRI’s pedigree breeding programme, which by that period was crossing improved semi-dwarf lines to combine plant type, grain quality, and pest and disease characteristics in a single variety. Like other IRRI releases of its era, IR64 carries the short, fertilizer-responsive plant type first popularised by IR8.
- Institution
- International Rice Research Institute (IRRI), Los Baños, Philippines
- Release year
- 1985
- Varietal group
- Indica
- Plant type
- Semi-dwarf, fertilizer-responsive
Grain quality and adoption
IR64 is particularly associated with grain quality: it produces long, slender grain with intermediate amylose content, a combination linked to the cooking and eating characteristics preferred across much of tropical Asia. This quality, together with broad adaptation, contributed to its very wide cultivation and to its frequent use as a quality and performance benchmark in rice breeding programmes.
Because it was so widely grown and studied, IR64 also became a common reference variety in rice research, including physiology, quality, and breeding studies. It appears in the parentage of many later varieties developed at IRRI and by national programmes.
Adaptation and use
IR64 was developed for irrigated and favourable rainfed lowland conditions in the tropics. It is grown as a staple food grain. Its suitability for any specific location depends on the local growing season, water regime, and prevailing pests and diseases, which vary widely across rice-growing regions.
Classification and status
- Botanical taxon
- Oryza sativa (indica group)
- Cultivar type
- Inbred line (indica)
- Registry status
- Historical — a widely grown released variety; current registry standing is not asserted here
- Documented by
- IRRI variety history and CGIAR rice-research literature
Relationships
Evidence-backed connections in the knowledge graph.
Related topics
Scope & limitations
Geographic scope: Developed at IRRI in the Philippines and grown very widely across South and Southeast Asia; local suitability is region- and season-specific.
Climate context: Bred for warm irrigated and favourable rainfed lowland rice systems in the tropics.
- Performance is environment- and management-specific and cannot be reduced to a single figure.
- Variety recommendations are set by national and local authorities and change over time; this page is descriptive, not a recommendation.
- The current registry standing of IR64 is not asserted here; it is documented primarily through IRRI’s variety history.
Sources
This article draws on the following authoritative sources. See our sources & methodology for how they are selected.
- [1]IRRI — International Rice Research Institute (opens in a new tab)High
International Rice Research Institute (IRRI)
Cited for: IR64 breeding history, release (1985), and grain-quality characterization
- Type:
- Research institute
- Jurisdiction:
- Global
- Accessed:
- 2026-07-12
Cited for: Rice-improvement context within CGIAR
- Type:
- Research institute
- Jurisdiction:
- Global
- Accessed:
- 2026-07-12
- [3]GBIF — Global Biodiversity Information Facility (opens in a new tab)High
Global Biodiversity Information Facility (GBIF)
Cited for: Species classification (Oryza sativa)
- Type:
- Reference database
- Jurisdiction:
- Global
- Accessed:
- 2026-07-12