Since its release in India during 1992, IR64 has become very popular in the irrigated areas of Tamil Nadu, Andhra Pradesh, Orissa, West Bengal, and Maharashtra. It has high yield, wide adaptability, good plant type, long slender grain, intermediate amylose content, and resistance to major insect pests and diseases.
IRRI scientists developed cytoplasmic male sterile (CMS) line IR66707A from IR64 by using Oryza perennis as a cytoplasmic source. Their intention was to use this CMS line to develop high-yielding, good quality hybrid rice. However, hybrids could not be developed without effective restorers.