الفهرس 
المقدمهOnly 14 pages are availabe for public view
 |  | from | 208 |  |  |
| | | from | 208 | | |
Abstract
Maize (Zea mays L.) is one of the most important cereal crops in
Egypt and lhe world. Maize in the world ranks the third surpassed only by
wheat and rice. It is a great importance for both human and animal
feeding. Therefore, efforts are focused on increasing productivity of this
crop by growing high yielding new hybrids under the most favourable
cultural practices.
The growth and yield of maize depend on many factors. from the
major factors are genotypes, plant population density, and nitrogen
fertilization. The optimum level of both factors varied widely according
to soil fertility, water supply, clay length and planting patterns, Duncan
(1972).
Nitrogen fertilization is among the most important cultural
practices, which control maize production (Mandour 1977 and Balko
and Russel 1980). Provision for an adequate supply of nitrogen
throughout the growing season is necessary and is one of the important
functions of soil management