Despite the importance of drought as a constraint, little
effort has been devoted to developing drought-tolerant rice
cultivars. Most improved cultivars grown in drought-prone
areas were originally bred for irrigated conditions, and were
never selected for drought tolerance. These cultivars have high yield
potential, but are often highly prone to yield reduction
under drought (IRRI, unpublished data). On the other hand,
some traditional rice cultivars grown in rainfed areas are highly
drought tolerant but have low-yield potential. In order to assure
high yield in non-drought years and an acceptable yield in
drought years, farmers require cultivars that combine highyield
potential with improved tolerance of drought.