Tackling Drought: IRRI Shows the Way

Because drought can push millions of people into poverty, IRRI scientists are developing drought-tolerant rice varieties to help Asian farmers.

Aerobic rice varieties, like these being tested at IRRI, can grow in conditions far too dry for commonly grown modern varieties.

Rice breeders at IRRI are developing new types of aerobic rice that combine the ability of some traditional but low-yielding varieties to grow in dry soils with the fertilizer responsiveness and yield potential of modern high-yielding varieties. The first generation of this so-called aerobic rice has been developed by crossing irrigated high-yielding varieties with some traditional types, and selecting the progeny under dry soil conditions. The resulting varieties are direct-seeded into dry soil in non-flooded fields and managed like a high-yielding wheat or maize crop. Irrigation is applied if available and needed, but no standing water is necessary.

IRRI researchers have demonstrated that some rice varieties (including some hybrids) are more tolerant to temperate stresses than mainstream high-yielding irrigated varieties, especially during the critical flowering and early grain-filling stages. Breeders use a screening process to find the most drought-tolerant varieties by depriving water to plants around the flowering period, and then selecting the best-yielding candidates. IRRI has identified many varieties combining high yield when conditions are good with the ability to yield 2–3 tons per hectare under conditions so dry that many popular varieties produce less than 1 ton per hectare.

IRRI scientists and collaborators are studying the genetic basis for this tolerance.