Investigating Efficiency of Non-chemical Methods to Management of Weeds in Forage Sorghum (Sorghum bicolor)

In order to investigate the efficiency of non-chemical methods management of weeds in forage Sorghum، an experiment was conducted in Varamin Research farm during 2010. The experiment was carried out in split factorial design with three replications. Treatments included cultivation at 3 leaf stage of sorghum، cultivation at 3 and 5 leaf stages of sorghum، weed free and weed infested as main plots and two levels of sorghum densities (190000 and 266000 plant/ha) and two levels of sorghum planting patterns (one and two row plant pattern) as factorial treatments in subplots. Weed density and biomass were measured 30 days after second cultivation and before second forage harvesting. Forage biomass was also measured at each harvesting. According to the results، weed density was decreased by cultivation (about 50%) but as the density of weed was very high، the effect of cultivation on weed biomass was not significant. Increasing density of sorghum+ two row planting pattern had positive effect on the final yield of sorghum. In general، integrating cultivation، density and planting pattern did not have significant effect on the final yield of sorghum and weed population، but the effects of cultivation at 3 leaf stage of sorghum + two row planting pattern and 19000 plant/ha+ two row planting pattern) on final yield were more favorable than other treaatment. It seemed that these treatments can be recommended in integrated weed management of sorghum.