ﺮرﺳﻲ رﻗﺎﺑﺖ ﮔﻨﺪم (. Triticum aesativum L) و ﻋﻠﻒ ﻫﺮز ازﻣﻚ (Cardaria draba ) در ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﻛﻮد ﻧﻴﺘﺮوژن

Effects of nitrogen supply on competition between wheat and three annual weed species. Weed Res., 37:391-40 This experiment was conducted to study the effect of wheat and- Hoary cress competition under different nitrogen levels on biological yield of these plants using a factorial experiment based on RCBD was conducted with three replications in Research Greenhouse of Faculty of Agriculture, University of Birjand during 2013.. Factors considered included nitrogen three levels (0.05, 0.1 and 0.2 gr/kg soil), wheat density in four levels (0, 4, 8 and 12 plants per pot) and Hoary cress density in four levels (0, 2, 4 and 6 plants per pot). Results showed That the greatest biological yields were obtained at high wheat and Hoary cress densities and at the highest fertilizer levels. Under competition conditions, it was observed that Hoary cress dry weight decreased with increasing wheat density, so that the lowest Hoary cress biological yield, was observed with 2 weed plants in interference with 12 wheat plants and at 0.05 gr/kg nitrogen fertilizer. The lowest biological yield of wheat was obtained at low wheat densities in competition with 6 plants of Hoary cress and at 0.05 g/kg nitrogen. The highest amount of this trait was observed with12 wheat plants density under weed- free conditions and 0.2 gr/kg nitrogen.