In order to study the competitive relations of three wheat cultivars with different densities of wild oat, an experiment was conducted in factorial arrangment based on completely randomized block design in field of Abosaeed Agricultural School of Feizabad, with three replications. Experimental factors were consisted of three cultivars of wheat (Falat, Sepahan, Pishtaz) and five wild oat densities (0, 5, 10, 20, 40 plant/m2). Result showed that the the highest yield was obtained in weed free conditions for all wheat cultivars. Pishtaz showed superiority in respect to competition ability, growth characteristics and yield potential, compared to othere cultivars, so that in density of 40 plant/m2 of wild oat grain yield of wheat cultivars reduced about 44.66, 42.6 and 34.12 percent for Falat, Sepahan and Pishtaz, respectively. These differences was significant at P<0.01 .The higher the wild oat density (20&40 plant/m2) the lowest vegetative and reproductive growth of wheat cultivars, specially in Falat. Finally
results confirm that, wild oat can reduce grain yield and harvest index of wheat cultivars throughout its effect on productive tillers number, wheat leaf area index, plant height, 1000 seed weight and kernel number in spike. These competitive effects occurred during the growing season and reproductive period of wheat. The yield reduction was different and depended to morphological and competitive characteristics of each cultivar. |
