The Effect of Feral Ray (Secale cereale) and Wild Mustard (Sinapis arvensis) Growth Characters on Yield Loss of Wheat (Triticum aestivum L.) Cultivars

This research was conducted as two separated experiments based on a randomized complete block design with three replications at research farm of Agricultural Faculty of Bu-Ali Sina University, Hamedan. In both experiments, Alvand and Sayson cultivars were one of the experimental factors which were planted at 450 plants m^-2. In the 1st experiment, feral rye (Secale cereale) plant densities of 0, 20, 40, 60 and 80 plants m^-2 and in the 2nd experiment, wild mustard (Sinapis arvensis) plant densities of 0, 8, 16, 24 and 32 plants m^-2 were the 2nd experimental factor, respectively. By increasing feral rye and wild mustard plant densities leaf area index, dry matter accumulation and weed growth rate, leaf area index duration and dry matter duration of weeds were increased. In each level of weed plant density, all above mentioned traits of weed in interference with Sayson were more than Alvand. Feral rye height in competition with both cultivars was not changed. But, wild mustard height in interference with Alvand was more than competition with Sayson. However in non-interference conditions, Sayson in traits of leaf area index duration, dry matter duration and grain yield has significant superiority than Alvan. But in interference condition with both weeds, these traits in Sayson were more affected than Alvand. Canopy height of Sayson was reduced in interference with both weeds. But canopy height of Alvand was increased in interference condition. Maximum leaf area index and growth rate, dry matter, leaf area index duration and dry matter duration of wheat cultivars were indicated positive and significant correlation with grain yield of both cultivars. In contrast, amount of above mentioned traits in each of two weed species had robust negative correlation with grain yield of two wheat cultivars. Generally, in interference with each two weed species, Alvand indicated better reaction than Sayson, and for sowing in spotty field to studied weeds is suggested.