بررسي رقابت در اجتماع گياهي سويا و سورگوم با استفاده از مدل عكس عملكرد

Assessment of competition between soybean and sorghum by reciprocal yield model

To assess the intra- and inter-specific competition between soybean (Glycine max L.) and sorghum (Sorghum bicolor (L.) Moench) by reciprocal yield model, an experiment was conducted at the Research Station of Faculty of Agriculture, University of Tabriz in 2000. The trial was performed as factorial based on Randomized Complete Block Design with three replications. The three factors including two soybean cultivars (Harkur and Williams), three levels of soybean densities (30,50 and 70 plant /m2), three levels of sorghum densities (5,10 and 15 plant 1 m) and soybean and sorghum monocultures at different densities. Interspecific competition coefficient of sorghum on soybean was greater than that for soybean on sorghum. Intraspecific competition coefficient for soybean was smaller than sorghum. Williamsʹs soybean cultivar showed higher competitive effects on sorghum compared to Harkur cultivar. The intraspecific competitive effects of sorghum were greater than that of soybean on sorghum. The relative competitive effects for biological yield of soybean in Harkur and Williams cultivars were 0.117 and 0.223, respectively. Meanwhile, Williams proven to be a stronger competitor for sorghum, the relative yield of Harkur soybean cultivar suffered a greater decrease from an increase in sorghum density, when compared to other soybean cultivar.