RADIATION USE EFFICIENCY OF MAIZE UNDER INFLUENCE OF DIFFERENT LEVELS OF NITROGEN FERTILIZATION AND TWO DIFFERENT SEASONAL CONDITIONS

Abstract

The objective of this study to estimate  the Radiation Use Efficiency  under effect of three levels of nitrogen (N₁ = 80 Kg N ha^-1,  N₂ =120 Kg  N ha^-1, and   N₃=160 Kg N ha^-1) for a set of maize hybrids include (Gloria, Market, Cruze and Draxma) in two different seasons in spring and fall  of 2017 in Qlyasn-Sulaimani. The experiment was conducted using split plot design with three replicates . The results revealed higher intensity of PAR in autumn season than that of spring (15.672 and 10.555)MJm^-2d^-1  respectively that led to higher RUE in autumn revealing (4.311,3.546, and 4.702)g MJ^-1 m^-2 under the effect of (N₁,N₂, and N₃) respectively, while the results of the autumn were higher (5.237, 4.681, and 6.019) g MJ^-1 m^-2  under the same levels of nitrogen fertilization, the highest application of nitrogen was more effective in autumn. The RGR and the rate of total dry matter accumulation were higher in autumn season displaying positive performance of studied  maize hybrids to the higher intercepted of solar energy as well higher temperature.