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.

Response of Bread Wheat (T. aestivum L.) to Nitrogen Fertilization and Foliar Application of trace elements Zinc and Iron and Thermal Capacity of Two Different Agro Climatic Zones

“…Heat use efficiency (HUE) for grain yield was obtained from the equation, HUE = Grain Yield Kg ha -1 / accumulated heat units ˚C day -1 (Tomar et al ., 2016). To evaluation the rate of dry matter accumulation, the Relative Growth Rate (RGR) was determined according to the equation, RGR g g -1 d -1 =ln W 2 -lnW 1 / t 2 -t 1 (Mohammed, 2018), where: lnW 2 is the natural logarithm of the plant weight at a later date, lnW 1 is the natural logarithm of the plant weight at a previous date, t 2 is the time 2 or later date, and t 1 is the previous date. The meteorological data of both locations are shown in the following table : Table (…”

“…The accumulated growing degree days in all wheat varieties increased with an increase in nitrogen levels from 120 to 180 kg N ha-1 (Sidhu and Raj, 2018). Accumulated dry matter varies according to the environmental factors during the growth stages along the crop life-cycle through the effect on the energy balance between photosynthesis and respiration (Mohammed andJaza, 2015, Mahdi andTopal, 2018). The high variability in N efficiency indicates to variability in yield potential in most agro-climatic zones, ( Aycicek andYildirim, 2006, Mandic et al ., 2015).…”