2.2 Samplings and measurements
In each plot, 20 randomly selected plants were labelled to record
tasseling, pollen shedding, silking, and mature date in four
experimental years. Plants in a plot were considered to be in a specific
phenological stage when 50% of the plants had reached that stage.
All the ears were harvested in two adjacent rows 3 m long in the center
section of each plot at maturity stage. Kernel number per ear (KN/ear)
was determined by counting row number per ear and kernel number per row.
Kernels of these ears were threshed by hand and over-dried at 80 ℃ to
constant weight. Five samples of 500 dry kernels were weighed in each
plot to determine 1000-kernel weight (TKW). Grain yield (g/ear) was
weighed and adjusted to 14% water content.