Iranian Society of Weed Science Iranian Journal of Weed Science 1735-3548 18 1 2022 03 21 Evaluation of resistance to mesosulfuron methyl+ idosulfuron methyl and mesosulfuron methyl+ idosulfuron methyl+ diflofenican herbicides in winter wild oat (Avena sterilis sub sp. ludoviciana) populations collected from wheat fields of Khuzestan province and preparing distribution map of populations Evaluation of resistance to mesosulfuron methyl+ idosulfuron methyl and mesosulfuron methyl+ idosulfuron methyl+ diflofenican herbicides in winter wild oat (Avena sterilis sub sp. ludoviciana) populations collected from wheat fields of Khuzestan province and preparing distribution map of populations 115 127 128793 10.22092/ijws.2022.353809.1387 FA Ali Joumi Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran Eshagh Keshtkar Department of Agronomy, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran Eskandar Zand Iranian Research Institute of Plant Protection, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran Hamidreza Sasanfar Iranian Research Institute of Plant Protection, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran Journal Article 2021 10 13 Forty-six suspected herbicide-resistant winter wild oat populations collected from wheat fields of Khuzestan province were screened in a whole plant bioassay using the recommended field dose of mesosulfuron methyl+idosulfuron methyl (Atlantis %1.2 OD) and mesosulfuron methyl+idosulfuron methyl+diflofenican (Othello %6 OD). The resistance index of two populations, with the highest percentage of herbicide resistance recorded at the screening tests, to the mentioned herbicides was tested in a dose-response experiment. Thirteen and six populations showed resistance to Atlantis based on Adkins and Moss methods, respectively. Also, 18 and three populations were classified as Othello resistant populations based on Adkins and Moss methods, respectively. This is the first report of resistance to Othello in winter wild oat populations collected from Khuzestan province. A distribution map of winter wild oat populations resistant and susceptible to herbicides was prepared based on the results of the screening test. Herbicide resistance index to Atlantis in two dose-response experiments for the studied populations was ranged between 8.9 and 15.1. Herbicide resistance index to Othello was ranged between 3.3 and 15.0. Due to an increase in herbicide-resistant populations to ALS inhibitors in Khuzestan province, herbicide-resistant winter wild oat management programs should be pursued more seriously. Forty-six suspected herbicide-resistant winter wild oat populations collected from wheat fields of Khuzestan province were screened in a whole plant bioassay using the recommended field dose of mesosulfuron methyl+idosulfuron methyl (Atlantis %1.2 OD) and mesosulfuron methyl+idosulfuron methyl+diflofenican (Othello %6 OD). The resistance index of two populations, with the highest percentage of herbicide resistance recorded at the screening tests, to the mentioned herbicides was tested in a dose-response experiment. Thirteen and six populations showed resistance to Atlantis based on Adkins and Moss methods, respectively. Also, 18 and three populations were classified as Othello resistant populations based on Adkins and Moss methods, respectively. This is the first report of resistance to Othello in winter wild oat populations collected from Khuzestan province. A distribution map of winter wild oat populations resistant and susceptible to herbicides was prepared based on the results of the screening test. Herbicide resistance index to Atlantis in two dose-response experiments for the studied populations was ranged between 8.9 and 15.1. Herbicide resistance index to Othello was ranged between 3.3 and 15.0. Due to an increase in herbicide-resistant populations to ALS inhibitors in Khuzestan province, herbicide-resistant winter wild oat management programs should be pursued more seriously. https://ijws.areeo.ac.ir/article_128793_f98414e46ce7bd5346fbdb77d8cf64a4.pdf