Wild Barely (Hordeum spontaneum koch) populations response to sulfosulfuron herbicide.

The main purpose of this research was to investigate the effect of sulfosulfuron, as a chemical herbicide, on different populations of wild barley in Iran. A factorial experiment was conducted under outdoor condition based on randomized complete block design (RCBD) with three replications at Fars Agricultural and Natural Resources Research and Education Center during 2014-2015. The main factors were 29 different populations of wild barley, application of sulfosulfuron WG 75% at 5 doses (0, 9.97, 9.97+9.97 (as a split dose at two stages), 19.95 and 29.92 g ai h-1) and different application times of sulfosulfuron (one- to three-leaf of Zadoks growth stage (ZGS11-13), at an early stage of tillering (ZGS21-23), and stage of stem elongation (ZGS31-33)). The growth traits of wild barley were evaluated 45 days after herbicide treatments. The results showed that sulfosulfuron decreased the growth of all wild barley populations, and the lowest fresh weight was obtained by the highest level of herbicide (29.92 g aih-1). Application a split dose (i.e. 9.97+9.97 g ai h-1) showed to slightly retard the growth of wild barely. Using sulfosulfuron at ZGS11-13 was found to have better effect on controlling wild barley. Populations of wild barley displayed various responses to different times and doses of herbicide application. Overall, the response of wild barley to the applied herbicide could probably be attributed to their inter-population variability and their ability to tolerate the herbicide.