Experiments were planted in two adjacent blocks that
received different irrigation treatments. The first block (Block
1) received irrigation throughout the life cycle of the crop
whereas the second block (Bock 2) received irrigation for only
28 days which is approximately two to three weeks to anthesis
so that water stress can coincide with the time of flowering.
The blocks were separated by four ranges, each 4.25 m wide,
to restrict lateral movement of water from the fully irrigated
block to the drought stress block. Irrigation water was supplied
with an overhead sprinkler irrigation system that dispenses
12 mm of water per week. Except for the different irrigation
treatments, all field management practices were uniform for
both the well-watered and water-stressed experiments.
Experimental hybrids were laid out in a 10 10 triplelattice
design in each block in single-row plots, 4 m long
with spacing of 0.75 m between rows and 0.50 m spacing
between plants within a row. Three seeds were sown per hill
and later thinned to two plants per hill two weeks after
planting (2WAP) to attain a population density of 53,333
plants ha1. Standard cultural practices were applied in field
maintenance.