The populations for upland experiments were derived
by crossing IR55419-04, a drought-tolerant improved
variety, with the highly drought-susceptible cultivars
Way Rarem (an Indonesian upland cultivar) and IR64
(a popular lowland cultivar). Bulk F3 seeds from the
two crosses were planted during the dry season of 2003.
F3 plants were harvested individually and their seeds were
used to constitute the population for screening. F3:4 seeds
were used in the 2004 experiments and F3:5 seeds harvested
from the non-stress treatments were used in the 2006
experiments