Effect of Different Nitrogen Levels and Application Methods on Weeds, Yield and Yield Components in Tir Wheat (Triticum aestivum L. var. leucospermum (Körn.) Farw.) N TOGAY 1 I TEPE 2 Y TOGAY 1 and F CIG 1 1 Yuzuncu Yil University, Faculty of Agriculture, Department of Field Crops, 65080, Van, Turkey 2 Yuzuncu Yil University, Faculty of Agriculture, Department of Plant Protection, 65080, Van, Turkey Abstract Fertilization is an important component of integrated weed management systems in wheat. This study was carried out to determine the effects of nitrogen (N) levels and application methods on the weed-crop competition in a well-adapted winter wheat (Triticum aestivum L. var. leucospermum (Körn.) Farw.) cultivar “Tir” in the absence of herbicide. The trial was conducted in a factorial randomized complete block design with four replications in two years (2005-06 and 2006-07). Three nitrogen levels (0, 60 and 120 kg N ha -1 ) and three application methods (broadcast on the soil surface, banded 10 cm broadcast between every crop row and banded 10 cm deep between every crop row) were applied. Weed density, weed biomass, grain yield, biological yield, plant height, spike length, numbers of seed per spike, 1000 seed weight, protein ratio in grain and shoot were investigated. The differences between treatments were not significant for weed density in both years. However, application of nitrogen up to 120 kg ha -1 increased total weed biomass, the lowest weed biomass were found to be 643 and 862 kg ha -1 with 0 kg N ha -1 in both years, respectively. While the highest weed biomass was found in soil surface on broadcast and 10 cm broadcast between every crop row,