Study on the Efficacy of Some Current Herbicides for Control of Wild Oat (Avena ludoviciana Durieu) Biotypes Resistant and Susceptible to Acetyl CoA Carboxylase (ACCase) Inhibitors

Abstract
Three separate greenhouse experiments were conducted in the greenhouse facilities of the Iranian Plant Protection Research Institute, Tehran, to study the efficacy of some ACCase inhibiting herbicides for control of resistant based on mechanism, resistance based on enhanced metabolism and susceptible wild oat biotypes. In each experiment, biotypes were treated separately by 17 herbicide treatments. To evaluate the effects of treatments, different characteristics including percent damage based on EWRC scores at 30 days after spraying, percent survived plants after spraying relative to before spraying and percent dry and wet weight of individual plants relative to control were studied. Results showed that the susceptible biotypes of wild oat were best controlled by Clodinafop propargyl (0.8 l/ha(, Pinoxadane (450 ml/ha) , Sulfosulfuron (26.6 g/ha), Sulfosulfuron+Metsulforon (45 g/ha), Iodosulfuron+ mesosulforon (350 g/ha), Prosulfocarb (3-4 l/ha(and Isoproturon+diflufenican (2-2.5 l/ha(. Tralkoxydem (1.2 l/ha (and Fenoxyprop-p-ethyl (1 l/ha(also to some extent could control susceptible biotypes. The best treatments for control of biotype based on enhanced metabolism were Isoproturon+diflufenican and Sufosoforon+metsulforon. Prosulfocarb and Iodosulfuron+ mesosulforon also to some extent could control this kind of biotypes. Resistant biotype based on mechanism also were controlled with Pinoxadane, Sulfosulfuron, Sulfosulfuron+metsulforon, Iodosulfuron+ mesosulforon (400 g/ha) and Isoproturon+diflufenican. Since AlS inhibitor could not control susceptible wild oat biotypes, it is necessary to repeat this part of experiment again.

Keyword: Herbicide resistance, Wild oat, Resistant based on mechanism, Resistant based on enhanced metabolism