Abstract:

The aim of the study is to identify the control efficacies of different dosages of pesticides on diamondback moth (Plutella xylostella) in cabbage and to select the optimum dosage. A field trial was conducted with 25 g/L spinosad suspension and 1% emamectin benzoate microemulsion in Junan County, Shandong Province in 2019. The results showed that the Plutella xylostella was controlled effectively by 25 g/L spinosad suspension with 18.75-25 g/hm² and 1% emamectin benzoate microemulsion with 1.5-2.25 g/hm². The control efficacy was 87.74%, 91.86%, 76.87% and 83.46% respectively after three days of application and was 90.68%, 95.40%, 85.79% and 90.58% respectively after seven days of application. For 1% emamectin benzoate microemulsion, the control efficacy of higher dosage was better than that of lower dosage. 25 g/L spinosad suspension with 25g/hm² had the best control efficacy, which could be up to 95.40% after seven days of application. The control efficacy of 25 g/L spinosad suspension was slightly better than that of 1% emamectin benzoate microemulsion after seven days of application. In conclusion, the two pesticides can be used as safe, effective and ideal pesticides, and their control efficacies were both above 85%. It is suggested that the two pesticides are used alternately in order to avoid resistance.

Key words: Pesticide, Dosage, 25 g/L Spinosad Suspension, 1% Emamectin Benzoate Microemulsion, Cabbage, Plutella xylostella, Control Efficacy