Resistance of Wild Oat (Avena ludoviciana Durieu) Populations toIodisulfuron+Mezosulfuron Herbicide

In order to investigate the resistance of 8 suspected Wild oat populations (Avena ludoviciana), collected from Shoosh, to Chevalier herbicide a whole plant bioassay and seed bioassay (screening and dose response tests) were carried out in 4 replication. This investigation was conducted during 1388 and 1389 in the Department of Weed Research, in Plant Protection Research Institute of Iran. Four weeks after herbicide application in the screening test in pots with recommended dose and in dose response assay with 1-32 fold of recommended dose at 2-4 leaf stage, plant fresh and dry weight percent, survived plant rate, and EWRC visual rating were measured. In seed bioassay in petri dish with the measurement of coleoptile length seven days after treating germinated seeds of sensitive population, discriminating dose was determined and used to treat all other populations. This survey, demonstrated the resistance of KHI, KHB, KHC, and KHA populations in Adkins methode and moss methode. These results were also confirmed by petri dish bioassay. On the base of these results, it is the first report of resistance of wild oat population to Iodisulfuron+Mezosulfuron (ALS inhibitor) herbicide in Iran