Response of grain yield of wheat and seed production of wild mustard and wild oat to nitrogen application and weed density

To study the response of grain yield of wheat and seed production of wild mustard and wild oat to application of different nitrogen levels and inter and intraspecific competition a field experiment was conducted at Islamic Azad University of Ahvaz-Iran. The results indicated that increasing nitrogen level increased the competitive ability of wild mustard and wild oat as result of this loss in grain yield of wheat was increased. The results showed that reduction of grain yield in single weed species competition of wild mustard and wild oat was less than mixed weed densities. The seed production of wild mustard and wild oat increased with increasing nitrogen levels and their densities while it decreased due to interspecific competition. The mean value of seed production of wild mustard in the application of 90, 150 and 210 kg N ha-1 was 3460, 3927.1 and 5478.3 seeds m-2 respectively whereas the seed production of wild oat was 1308, 1634 and 1675 seeds m-2 respectively. Seed production of wild mustard was very high as compared wild oat.