Emamectin benzoate is a new semi-synthetic insecticide based on abamectin.Emamectin benzoate has the characteristics of high efficiency,broad spectrum and so on.Emamectin benzoate is widely used in the control of many pests that harm vegetables,fruit trees,rice,cotton and other crops,which has the highest activity against Lepidoptera,mites and Coleoptera pests.Emamectin benzoate,having stomach toxicity and contact toxicity,is widely used to control Plutella xylostella that harm cruciferae vegetables.However,the current formulations of Emamectin benzoate are mainly microemulsion(ME)and emulsifiable concentrate(EC),which have the disadvantages of large usage of emulsifiers and organic solvents,high control cost and serious environmental pollution.Emulsion,oil in water(EW)and suspension concentrate(SC)use water as dispersing medium,water dispersible granule(WDG)does not use organic solvent,and avoids dust pollution.Processing emamectin benzoate into the above three formulations not only provides efficient,safe and environmentally friendly control agents for Plutella xylostella,but also conforms to the concept of green development of pesticide industry in China.In this study,the optimized formula was obtained based on the screening of the components of EW,SC and WDG,the quality control index of the optimized formula was determined,and its contact angle and control effect against Plutella xylostella were investigated.(1)Optimized formula and application performance of emamectin benzoate EWThe effect of emulsifier types,dosage and emulsifying method on the formation and stability of Emamectin benzoate EW were studied.The results showed that the types,dosage of emulsifier and emulsifying method could significantly affect the formation and stability of Emamectin benzoate EW.The optimized formula of 2%Emamectin benzoate EW was 2%Emamectin benzoate,5%fatty acid methyl ester,6%Synerg 848,deionized water to 100%,the quality indicators of the formula conforms to FAO standard.The wettability of Emamectin benzoate EW on cabbage leaves was slightly better than that of commercial EW.At the same dosage,the control effect of Emamectin benzoate EW against Plutella xylostella was slightly worse than that of commercial EW.(2)Optimized formula and application performance of emamectin benzoate SCBased on the selection of wetting dispersant and thickener,the optimized formula of 3%Emamectin benzoate SC was obtained by orthogonal test design,using the suspension rate,water separation rate and viscosity as evaluation indexes.The optimized formula was 3%Emamectin benzoate,3%wetting agent Morewet EFW,4%dispersant D1008,5%glycol,0.2%xanthan gum,1.5%magnesium aluminum silicate,0.1%defoamer,deionized water to 100%.The results showed that the quality indicators of Emamectin benzoate SC were up to standard,the wettability of Emamectin benzoate SC on cabbage leaves was slightly better than that of commercial SC,and the control effect of Emamectin benzoate SC against Plutella xylostella was better than that of commercial SC at the same dosage.(3)Optimized formula and application performance of emamectin benzoate WDGThe wetting agent,dispersant,binder and disintegrating agent were screened by single factor method.The optimized formula of 5%Emamectin benzoate WDG was obtained by orthogonal test design with the suspension rate and disintegrating time as evaluation indexes.The optimized formula of 5%Emamectin benzoate WDG was as follows:5%Emamectin benzoate,4%dispersant Morewet D425,2%wetting agent MORWET EFW,3%binder polyethylene glycol,7%disintegrating agent urea,diatomite to 100%.The results showed that the quality indicators of Emamectin benzoate WDG were up to standard,and the wettability of Emamectin benzoate WDG on cabbage leaves was slightly better than that of commercial WDG.At the same dosage,the control effect of WDG against Plutella xylostella was equivalent to that of commercial WDG. |