| چکیده انگلیسی مقاله |
In order to study the competitive performance of spring bread wheat (Triticum aestivum) cultivars with wild oat (Avena lodoviciana), a field experiment was conducted in research farm of Ramin University of Agricultural and Natural Resources, Khouzestan in 2010-2011 cropping season. The experimental design was strip blocks with three replications. Four wild oat densities (0, 40, 80 and 120 plant.m-2) were assigned to horizontal plots and spring bread wheat cultivars (Chamran, Baz, Atrak, Arvand, Maroon, Shoeleh, Chenab, Vee/Nac and Falat) were randomized in vertical plots. Competition indices calculated and analyzed for each cultivar. The highest competition index was obtained for 40 and lowest at 80 and 120 plants.m-2. Results showed that new index was better than older by many aspects, as there is 8 category scales including highly susceptible, susceptible, semi-susceptible, moderate, semi-tolerant, tolerant, high tolerant, and immune. Newly cultivars Chamran, Daz, Virinak Vee/Nac and Falat with 1.3, 1.4, 1.6 and 1.8 competition indices, respectively, were identified as semi susceptible and Maroon with 7.0 as tolerant, but there is no immune, high tolerant, susceptible, or high susceptible among these 10 cultivars. According to the results of the present experiment, tolerance of Maroon cultivar implies that low tillering cultivars with more than 400 plants.m-2 density may decrease weed damage by earlier wheat canopy closure. |