Tamer Üstüner, İlker Ağaoğlu
Wheat accepted as a strategic product in world countries and in Türkiye. Weed species are among the main factors directly affecting yield and quality in wheat production. Herbicides have great importance in the control against weeds that are a problem in wheat production. In this study, Empisa SL (MCPA 400 g/L) herbicide and the reference herbicide Handle EC (200 g/L bromoxynil octanoate + 200 g/L MCPA iso-octyl ester) were used. The field trials were conducted in a wheat field located in Oğuzeli District, Gaziantep Province, Southeastern Anatolia Region, Türkiye, during the 2020–2022 growing seasons. The experiment was established according to a Randomized Complete Block Design (RCBD) with six characters (four doses of the test herbicide, comparison drug, and an untreated control parcel) and four replications. During the second assessment, which was used as the basis for evaluating biological efficacy, the target weed in the untreated control plots was observed to be at the 4–6 leaf growth stage. The efficacy values were calculated based on the symptoms observed on the leaves and shoots of the weed 29 days after herbicide application (second assessment). Within the scope of this study, Empisa SL herbicide and Handle EC were found to exhibit similar levels of efficacy against wild mustard (Sinapis arvensis L.). Therefore, only their effects on wild mustard were evaluated and discussed separately in this study. In this study, the recommended application rates of Empisa SL (250 mL/da) and Handle EC (200 mL/da) provided 93.78% and 95.30% control of wild mustard, respectively. Statistical analysis indicated that the efficacy of the two herbicides did not differ significantly, as both treatments were classified within the same statistical group (b). Based on these findings, the biological efficacy of Empisa SL applied at 250 mL/da against wild mustard (S. arvensis) was considered satisfactory, and no phytotoxic effects were observed on wheat.