EFFECT OF PLANT DENSITY, GENOTYPE AND THEIR INTERACTION ON AGRONOMICAL, PHYSIOLOGICAL AND YIELD TRAITS OF MAIZE (Zea mays L.)

Maximum yield per unit area may be obtained by growing maize hybrids that can tolerate high plant density. The main objective of the present investigation was to assess the effects of elevated plant density (PD), genotype (G) and G×PD interaction on maize traits. A set of 28 Egyptian commercial modern hybrids of maize, were evaluated in the field under four plant densities using a split plot design with three replications in two years. Increasing PD from 47,600 (D1) to 71,400 (D2), 95,200 (D3) and 119,000 (D4) plants/ha caused a significant reduction in grain yield/plant, ears/plant, kernels/plant, kernels/row, rows/ear, 100-kernel weight, leaf angle, chlorophyll concentration index, penetrated light at ear and bottom, stem diameter, ear leaf area, leaf area to produce 1g grain, but caused a significant increase in grain yield/ha (GYPH), plant height, ear height, leaf area index, days to anthesis and days to silking. Significant differences were observed among commercial hybrids; single crosses were superior to 3-way crosses for most studied traits under all plant densities. This study concluded that G × PD interaction had significant effects on all studied traits of maize. The highest GYPH was recorded in descending order by P3444, 30P74 and SC131 under D1, P3444, P3433 and SC 168 under D2, SC 235, SC 90 and P3444 under D3 and SC 235, P3444 and P3433 under D4. Our findings concluded that yield of maize can be increased significantly in Egypt, if farmers choose to plant hybrids at two fold of the recommended plant density.