Light Interception and Radiation Use Efficiency Response to Nitrogen Changes of winter cereals

In order to impact of nitrogen different rate on light interception and radiation use efficiency in winter cereals, an experiment was carried out in research field of Gonbad-e- Kavous University with four replications during 2013-2014. Treatment included Cereals: bread wheat Koohdasht, durum wheat Seimareh, six row barley Sahra, two row barley Khoram, hull less barley Line 17, triticale Canadian and oat Javaniloo and nitrogen fertilizer at two levels: zero and optimum (bread wheat 150 kg.ha-1, durum wheat 120 kg.ha-1, two row barley 120 kg.ha-1, six row barley 210 kg.ha-1, hull less barley 150 kg.ha-1, oat 90 kg.ha-1and triticale 240 kg.ha-1). Results indicated that Zero and optimum amount of nitrogen rate had no significant effect on extinction coefficient. K gained for triticale 0.670±0.03, bread wheat 0.860±0.03, for durum wheat 0.770±0.03, for six rowed barley 0.790±0.03, for two rowed barley 0.800±0.03, for hull less barley 0.740±0.05 and for oat 0.760±0.04. Radian use efficiency obtained from 2.02 to 2.78 grMJ1.m-2 in cereals. Radiation use efficiency gained for oat 2.17± 0.048, for durum wheat 2.02±0.07, for bread wheat 2.42±0.13, for two rowed barley 2.33± 0.09, for hull less barley 2.52±0.11, for six rowed barley 2.39±0.08 and for triticale 2.78± 0.14