Studying the effect of ionic biosurfactant levels on the efficiency of Bentazon herbicide in soybean fields of Moghan plain

Research Aim: The aim of this study was to investigate the effect of Bio-surfactant on the efficacy of Bentazone in weed control in soybean. For this purpose a randomized complete block design experiment was conducted in three replications in research farm of Agriculture and Natural Resources Ardebil (Moghan) in the 2017-18 crop year. Research method: Treatments consisted of Bentazon at a dose of 0, 2 and 2.5 lit. ha-1 and Bio-surfactant at a dose of 0, 1 and 2 lit. ha-1. Each plot was composed of two halves treatment and control. Weed common lambsquarters, johnson grass and pigweed are the dominant traits that were measured and soybean yield was calculated at the end. Findings: The results of analysis of variance showed that 30 days after spraying, the interaction of herbicide doses and biosurfactant doses on the traits of density and fresh weight of lambsquarters, density, fresh and dry weight of the Jonson grass, density, fresh and dry weight of the pigweed and 45 days after spraying, the interaction of the two factors on fresh and dry weight of lambsquarters, density, fresh and dry weight of Jonson grass, density and fresh weight of pigweed were significant. The results of the mean comparison showed that the highest percentage of control of lambsquarters (97%) was commonly related to all bentazon herbicide treatments with the additive of biosurfacent. The highest percentage fresh weight control of lambsquarters (100%) was related to 2.5 liters of bentazon without application and with the addition of the additive of biosurfacent. The highest control percentage density of Jonson grass (92%) was observed for all bentazon herbicide treatments with addition of biosurfactant. The highest percentage of fresh weight control of Jonson grass (90.44%) was commonly related to the treatment of 2.5 liters of bentazone with the additive of biosurfactant. The highest control percentage dry matter weight of Jonson grass (97.3%) was commonly associated with Bentazon application with and without the application of biosurfactant. The highest percentage control of pigweed density (97.86%) was commonly associated with bentazon herbicide treatments with and without additive of biosurfacent. The highest percentage control of fresh weight pigweed (93.69%) was observed for 2 liters of bentazone with biosurfactant and ail treatments of 2.5 liters of bentazon. The highest percentage control dry weight of pigweed (94.72%) was commonly related to application of bentazon herbicide with and without application of biosurfactant. On the yield and yield components of soybeans, the effect of different treatments on seed number per pod, number of pods per plant, number of seeds per plant, grain yield, oil percentage, dry matter percentage and soybean protein content were significant but for plant height and 100-seed weight did not show significant.