Barely Weed Species (Hordeum spp.) Response to Sulfosulfuron at Different Rates and Times of Applications

This experiment was conducted at Research Green-house، Department of Weed Research، Iranian Plant Protection Institute، to evaluate the efficacy of sulfosulfuron rates in controlling of barely weed species (including Hordeum murinum، H. spontaneum، H. distinchom، H. vulgar) in the 2007. First factor was different times of sulfosulfuron application including 2، 4، 6، 8 and 10 leaf stages and the second factor was different sulfosulfuron application rates (0، 13، 26، 39 and 52 g ha-1). The experimental type was completely randomized blocks with factorial arrangement and four replications. According to the results، sulfosulfuron at the recommended time 2 to 6 leaf stages provide acceptable control of the wild barely (H. spontaneom). These stages were increased to 8 leaves stage for mouse barely (H. murinum L.) and H. vulgar. But، it was 2 to 4 leaves stage for H. distinchom. However، it did not need to increase the rate due to appropriate time of sulfosulfuron application and complete control of weeds was achieved with the recommended rate (27 g ai ha-1). On the whole، delay of mentioned application times caused increasing the sulfosulfuron rate and these rates depend on application time and weed species.