The Importance of Crop Rotations for Wild Oat (Avena sterilis L.) Resistance to Herbicides in Cukurova Region, Turkey

This study was conducted between 2013 and 2015 to determine the changes in the populations of wild oat (Avena sterilis L.) coverages, resistance and weed coverages based on the crop rotation applied at fields where wheat was being grown in Osmaniye Province and to reveal the relationship between the crop rotations and the resistance developed in wild oat by Clodinafop-propargyl with the Acetyl-CoA Carboxylase (ACCase) mode of action, Mesosulfuron-methyl + Iodosulfuron-methyl sodium and Pyroxsulam of the Acetolactate Synthetase (ALS) effect mechanism. By determining crop rotation systems for May and August in 103 fields selected in the year 2013, the coverage changes in the populations of wild oat and weeds and the resistance in wild oat poulations were determined. As a result, 48 different crop rotation systems were determined, wild oat resistance disappeared in the wheat + sunflower + sunflower rotation which was one of the most frequently preferred rotation, while the resistance index (RI) of wild oat against the ACCase inhibitor fell (RI<2.00) in the two-crop rotations involving maize as wheat/maize + maize + maize, wheat/maize + wheat/maize + wheat, wheat + wheat/maize + wheat and wheat/maize + wheat/maize + maize. In the three-crop rotation systems, resistance against ALS decreased in wheat/peanut + wheat/sesame + wheat, and resistance against ACCase decreased in wheat/maize + maize/peanut + peanut. It was revealed that the producers did not prefer four crop rotation much, and fallow did not change resistance indices. The wild oat resistant populations and coverages in the Osmaniye Province were determined for the first time, and the interactions of crop rotations are presented.