Effect of plant density and nitrogen fertilization on the productivity of some yellow maize hybrids

The study investigated the effects of plant density, nitrogen fertilization rates, and maize hybrid se-lection on the growth, yield, and yield components of two yellow maize hybrids (SC 168 and SC 180) over two growing seasons in Egypt. A split-split plot design with three replications was used. Main plots were three plant densities, sub-plots were three nitrogen levels, and sub-sub-plots were the two hybrids. Growth attributes, yield components, and grain yield were evaluated. Results showed the SC 180 hybrid had higher 100-kernel weight (in one season) and grain yields than SC 168, indicating the importance of high-yielding hybrid selection. Increasing nitrogen from 40 to 80-120 kg/feddan increased 100-kernel weight (in one season) and grain yield in both seasons, emphasizing proper nitrogen fertilization. Higher planting den-sities of 25,000 and 30,000 plants/feddan increased grain yield versus 20,000 in both seasons, suggesting potential yield gains from optimized densities. Two- and three-way interactions between factors signif-icantly impacted yield variables, indicating nitrogen and density effects depending on the hybrid and vice versa. Combinations of SC 180, high nitrogen, and high density produced the numerically highest 100-kernel weight and grain yield overall in the second season.