Investigating the Distribution of Clodinafoppropargyl Resistant Wild Oat (Avena ludoviciana) Populations in South Western Iran

To evaluate the distribution of clodinafoppropargyl resistant wild oat to in south western Iran (Khuzestan province), 50 fields which were sprayed with aryloxyphenoxypropionate herbicides were sampled. Those fields at which wild oat had been controlled efficiently by these herbicides were selected for the experiment. Populations (50 suspicious to resistance and 1 susceptible) were studied in a randomized complete block design with four replications in 2005. Populations of wild oat were sprayed during two- to four- leaves stage using the recommended dose of herbicide. Shoot biomass, survived plant and EWRC visual rating, were recorded four weeks after herbicides application. Longitude and latitude of different sampling locations were registered using GPS. Grouping populations using cluster analysis showed that 52% of populations were resistant, 28% were suspicious to resistance and only 18% of populations were susceptible and semi susceptible. Furthermore resistant populations were detected in all of parts of khouzestan province.