Study On 34.5% Emamectin Benzoate-Chlorfenapyr Water Dispersible Granule

As people care their health more and more,the pollution-flee production of vegetables was also cared more and more.So it was one of the important guarantee that using the water dispersible granule(WDG) of water-based pesticide new formulations to control the insects of vegetables.This paper aims to screen out the best ingredient percentage of Emamectin benzoate and Chlorfenapyr,and machining them into WDG,in order to control the important vegetable insects of Prodenia litura(Fabricius) effectively. Thus,this paper has been studied from the following aspects.The toxicity in the lab to Prodenia litura(Fabricius) larvae was tested with spot and leaf-dipping.Emamectin benzoate and Chlorfenapyr that had high toxicity to Prodenia litura(Fabricius) 3^nd instar larvae were screened out from seven common pesticides. When tested with leaf-dipping 48 hours later,the LC(50) of Emamectin benzoate is 0.1182mg/L,and the LC₅₀ of Chlorfenapyr is 0.8232mg/L.The best ingredient percentage was screened with Horsfall toxicity test design and leaf-dipping.The results showed that when the ingredient percentage of Emamectin benzoate and Chlorfenapyr was 1:16.25,the synergistic effect was the most obvious,and the co-toxicity coefficient was 316.52.Various auxiliary agents were screened with single factor experimentation,and the formulation was optimized with orthogonal trail design,finally the best formulation of 34.5%Emamectin benzoate- Chlorfenapyr WDG was screened out.The formulation was consisted of Emamectin benzoate and Chlorfenapyr as raw material 34.5% (Emamectin benzoate 2%,Chlorfenapyr 32.5%),BX as wetting agent 6%,NNO and Polyoxyethylene dodecyl alcohol ether mixed in the percentage of 1:1 as dispersing agents 6%,Ammonium sulfate as cracking agent 5%,PEG200 as adhesive 1%,China clay and Bentonite mixed in the percentage of 1:2 as carrier complementing to 100%. After the test of the all-around items of the sample,the indexes were as follow:the content of Emamectin benzoate was 2.1%,and the content of Chlorfenapyr was 32.7%,and the wetting time was 41s,and the suspending ratio was 88.2%,and the cracking time was 95s, and the content of water was 1.6%,and the pH was 6.8,and the decomposing ratio in hot store was 1.6%.The toxicity tested in the lab showed that when Prodenia litura(Fabricius) 3^nd instar larvae treated with leaf-dipping 48 hours later,the LC₅₀ of this formulation was 0.2813mg/L,and lower than the antitheses pesticides of 10%Chlorfenapyr SC and 4.5% Beta-Cypermethrin EC obviously.The field controlling trail was carried out with the formulation of 34.5%Emamectin benzoate- Chlorfenapyr WDG and the antitheses pesticides of 2.0%Emamectin benzoate ME and 10%Chlorfenapyr SC to Prodenia litura(Fabricius) and Plutella xylostella (Linnaeus).The results showed that when the dosage was 8g/667m² in the field,the formulation of 34.5%Emamectin benzoate- Chlorfenapyr WDG had well controlling effect to Prodenia litura(Fabricius) and Plutella xylostella(Linnaeus),and the controlling effect was 97.50%and 98.23%respectively 7d later,and no harm appearing.Thus,the commendable dosage of 34.5%Emamectin benzoate- Chlorfenapyr WDG in the field was 8g/667m².