اثر رقابت يولاف وحشي بر عملكرد و اجزاء عملكرد سه رقم گندم زمستانه

Competitive effects of wild oat (Avena loduviciana) on yeild and yield components of three winter wheat varieties

Field experiments were conducted during the 1999-2000 growing season at the agricultural experimental station of Ferdowsi University of Mashhad. The aim was to investigate the competitive ability of three winter wheat varieties with different levels of wild oat densities and its effects on yield and yield components of the wheat varieties. Wild oat caused 5 to 32 percent yield reduction in wheat, depending on wheat cultivars and wild oat densities. Among wheat varieties, C-73-5 was the most competitive variety and Alamoot was the least competitive variety in different levels of wild oat densities. Ln each variety, with the increase of wild oat density, the rate of yield reduction was enhanced. While at the highest level of wild oat density, the amount of this reduction in Alamoot and Bezostaia compared with the control treatment was significant. The reduction in Alamoot was due to the significant reduction of the number of produced tillers in each plant during the seasonal growth and wild oat interference. In Bezostaia, the reduction was due to competitive effects and shading of wild oat on this variety during the reproduction period of the plants.