Kalifa et al. (1981) studied the effect of nitrogen on an
open-pollinated variety of corn which was given as ammonium
nitrate applied as nitrogen source. His results indicated that
ammonium nitrate fertilizer increased the number of days to
mid- tasseling, mid-silking and shelling percentage. Singh
et al. (1986) found that the biological yield, content and uptake
of nitrogen in grain and stover of maize were highest with
nitrogen as urea applied in two split dressings. Sawi (1993)
and Omara (1989) observed that nitrogen had significant effects
on chemical composition of leaves, plant height, leaves,
internodes number per plant at early stages. Shoat and root
dry weight and cob number per plant. Nitrogen also significantly
affected final seed yield and some yield components
such as number and weight of cobs/m2 and weight of seeds
per cob, also significantly affected straw yield