After interviewing smallholder farmers throughout South and Southeast Asia, one of the top needs they mentioned is development of shorter duration rice varieties with only 100 days from sowing to harvest. Some farmers want to have more time to prepare for the next season crop, whereas other farmers are concerned about irrigation water running out during the dry season. Another benefit in countries such as the Philippines is reducing the risk of adverse weather (e.g., typhoons) affecting the crop compared to longer duration varieties.
In an article recently published in Crop Science, a diverse group of researchers from the International Rice Research Institute (IRRI) comprising agronomists, physiologists and breeders report on the advanced high-yielding, earlier-maturing lines for tropical Asia. The lines were developed from the IRRI's irrigated rice breeding pipeline.
The research team identified key agronomic traits for high yield in short-duration rice (SDR) that will assist future breeding efforts. The team found that low source-to-sink ratio was the major yield constraint of SDR and suggested that breeding should aim to enhance source capacity during grain filling. Importantly, some new SDR breeding lines yielded 11-38% higher than the most popular short-duration variety. Taken together, these findings indicate enormous potential for developing improved short-duration rice varieties in the future.