The experimental site was adjacent to that of experiment 2, and the crop was sown on the same
day as the first sowing (S1) of experiment 2. The
crop received full irrigation twice weekly of 25 mm
each time to supplement rainfall. A total of seven
treatments were laid out in a randomised complete
block design with four replications. The seven treatments
were control -- 100% sunlight throughout
and three solar radiation levels (72, 46 and 22%)
obtained by using shade cloths either from panicle
initiation (PI) to anthesis (65-100 DAS) or from
anthesis to maturity (100-135 or 149 DAS) depending
on the time of maturity. The different shading
treatments were applied using Sarlon shade cloths,
draped over a steel frame about 1.5 m high, covering
an area of 3.25 m X 1.25 m of each plot and forming
a skirt down to about 0.3 m above ground level on
each side