نوع مقاله : مقاله پژوهشی
To evaluate interference effects of volunteer barley on growth indices of six wheat cultivars, a study conducted in Sabzevar region during 2007-2008 growing season. The experiment was established as randomized complete block design with factorial arrangement and three replications. The treatments were six wheat cultivars in weedy and weed free situation. The studied cultivars including: 1- Chamran 2- Gascogen 3- Mahdavi 4- Pishtaz 5- Shiraz and 6- Falat with densities of 350, 375, 375, 400, 400, 325 seed m-2. Valfajr cultivar was used as a volunteer barley with density of 50 plant m-2. Base on variance analyze results volunteer barley interference reduced grain yield, leaf aria index, relative growth rate, crop growth rate, height and dry matter accumulation of wheat cultivars. The maximum of grain yield in monoculture and mixedculture was obtained in Shiraz and Mahdavi cultivars, respectively and the minimum values was found in Gascogen and Chamran cultivars, respectively. The maximum of leaf area index in monoculture and mixedculture were in Mahdavi cultivar, which could be caused by higher height and thus increased shading on volunteer barley and limitation on its growth. Comparison of cultivars relative growth rate in monoculture and mixedculture showed that Mahdavi cultivar had minimum reduction of relative growth rate. Moreover crop growth rate of Shiraz cultivar in monoculture and Mahdavi cultivar in mixedculture was greater than other cultivars. Results showed that yield of evaluated cultivars in volunteer barley interference situation were affected by height, leaf area index, relative growth rate, crop growth rate and accumulated dry matter, and Mahdavi cultivar showed better performance in these traits.
Keywords: Grain yield, Competition, Leaf area index, Relative growth rate, Crop growth rate, Dry matter accumulation