Practical attitude to predict the production and economic profit of wheat cultivars in interference with feral rye using regression models

In order to determine the practical method to predict economic production of wheat in competition with feral rye by using regression models, a factorial experiment was carried out based on randomized complete block design with three replications in Dargaz, Iran. Experimental factors were included wheat cultivars (Sayson, Alvand, Chamran and Sepahan) and feral rye densities (0, 20, 40, 60 and 80 plants m-2). The results showed that increasing feral rye density, reduced biological and grain yield of wheat cultivars. In contrast, biological yield, grain yield, spike number per unit area of weed and infestation percentage of weed seed was increased. The lowest and the highest initial slope (Parameter I) of grain and biological yield loss was obtained in Sepahan and Chamran cv., respectively. At all density levels, grain yield of Alvand cv was superior to other cultivars. The highest amount of biological yield, grain yield, spike number of weed and percentage of crop infestation was obtained in Chamran cv. In the range of acceptable infestation level of wheat to weed seed (0-7 Percent), the lowest and highest feral rye density that was led to same infestation, were estimated in Chamran and Alvand cv., respectively. The highest production and gross profit was obtained in both Alvand and Chamran cultivars. Generally, Alvand cv. in addition to the negative effect on weed production, had a high gross profit. So in experimetal region, mentioned cultivar is recommended for planting in feral rye infested fields