The study was carried out at the Agricultural Research and Experimental Center of the
Faculty of Agriculture, Moshtohor. Five statistical procedures of relating yield components to yield,
i.e., simple correlation, path coefficient analysis, stepwise regression, multiple regressions and factor
analysis were applied to yield contributing characters to determine their functional relationships to
yield and determine the effect of foliar application of zinc sulphate (zero, 0.2 and 0.4%) and six
nitrogen fertilizer levels (60, 80, 100, 120, 140 and 160 kg/fed) on growth, yield and yield components
in maize. The obtained results were as follows: Highly significant positive correlation values were
detected between grain yield/plant and each of ear height, ear diameter, ear length, number of
kernels/row, number of rows/ear and 100-kernel weight. Kernel ear weight had the most direct effect
on grain yield/plant followed by direct effect of ear diameter, ear height and ear length. In Multiple
linear regressions, the relative contribution for all yield factors explained 88.3% of the total variation
in grain yield. The stepwise regression show that, kernel ear weight, ear height, ear length, ear
diameter and 100-kernel weight were the most contributing variables in grain yield of maize (88.2% in
grain yield variation). The factor analysis grouped the studied variables into two factors, which
explained 90.57% of the total variability in the dependence structure. The first factor contributed
49.16% while, the second factor was responsible for 41.4% of the total variability. Zinc application as
spray resulted in significant increases in plant height, stem diameter, ear length, ear diameter, No. of
kernels/row, ear weight, kernels ear weight, 100-kernel weight, grain yield/plant and grain yield/fed in
both seasons, ear height and No. of ears/plant in the second season. Applying of 140 or 160 kg N/fed
increased significantly all growth characters, yield and yield components in the first and second
seasons. The interaction between spraying of zinc and N fertilizer levels had significant effect on plant
height, ear height, ear length, ear diameter, No. of kernels/row and grain yield/fed in the first and
second seasons, stem diameter in the first season and No. of rows/ear, kernels ear weight and grain
yield/plant in the second one. The highest values obtained for grain yield plant and fed were detected
by spraying with zinc at (0.4% Zn So4) and applied 140 N/fed. |
