Studies On The Preparation And Performances Of Triadimefon Microcapsule Suspensions Using Different Wall Materials

Microcapsule formulation has many advantages such as controlled release,precise release,control of phytotoxocity,low toxicity,environmental-friedly,and so on.Microcapsule technology is an important development direction of pesticide formulation processing.Triadimefon can prevent many crop diseases,such as Wheat Take-all,Wheat Powdery Mildew,and so on.It also has a good regulating effect on crops when used properly.However,many reports have shown that triadimefon can easily cause phytotoxocity to crops when used improperly or in adverse environmental conditions.Triadimefon can be prepared into microcapsule and processed into microcapsule suspension formulation,which can not only increase its effective period,but also prevent and mitigate its side effects on crop seeds and crops.This paper studied the preparation conditions about 3%triadimefon microcapsule suspensions using urea-formaldehyde resin and melamine-formaldehyde resin.Single factor experiments and response surface methodology were employed to optimize the preparation condition.The experiments tested the control effects of the triadimefon microcapsule suspensions using two different wall materials on wheat Take-all in pot,and the mitigation effects of 3%triadimefon microcapsule suspensions using two different wall materials on the phytotoxocity of triadimefon to wheat.The primary results were as follows:1.The experiment investigated the preparation process of triadimefon urea-formaldehyde resin microcapsule suspensions.The dosage of core material was unchanged.Single factor experiment was employed to optimize the preparation conditions such as the dosage of urea-formaldehyde resin,the kind of emulsifiers,the dosage of emulsifiers,initial temperature,terminal pH,solidifying temperature,emulsifying stir-speed,then response surface methodology were employed to optimize the preparation condition based on encapsulation rate.The optimal preparation condition were:the dosage of urea-formaldehyde resin was 32.38%,emulsifier was a mixture of 10%Tween 20 and 5%SMA(1:1)and the dosage was 2.65%,initial temperature was 18℃,terminal pH was 3,solidifying temperature was 70℃,emulsifying stir-speed was 800 r/min.2.The experiment investigated the preparation process of triadimefon melamine-formaldehyde resin microcapsule suspensions.The dosage of core material was unchanged.Single factor experiments was employed to optimize the preparation conditions such as the dosage of melamine-formaldehyde resin,the kind of emulsifiers,the dosage of emulsifiers,initial temperature,terminal pH,solidifying temperature,emulsifying stir-speed,then response surface methodology were employed to optimize the preparation conditions based on encapsulation rate.The optimal preparation condition were:the dosage of melamine-formaldehyde resin was 36.08%,emulsifier was a mixture of 10%SDBS and 5%SMA(1:3)and the dosage was 2.05%,initial temperature was 20℃,terminal pH was 5,solidifying temperature was 68℃,emulsifying stir-speed was 800r/min.3.The release properties of the triadimefon microcapsule suspensions using two different wall materials in aqueous solution were measured.The results showed that the microcapsule suspensions exhibited good sustained release effects in 28 days.4.The experiment assessd the control effects of the triadimefon microcapsule suspensions using two different wall materials on wheat Take-all in pot.The result indicated that the control effect of the 3%triadimefon urea-formaldehyde resin microcapsule suspensions was 84.62%,and the control effect of the 3%triadimefon melamine-formaldehyde resin microcapsule suspensions was 86.28%.5.The mitigation effects of 3%triadimefon microcapsule suspensions using two different wall materials on the phytotoxocity of triadimefon to wheat was studied.The result indicated that the height and weight of seedling plant increased obviously in the treatments using 3%triadimefon microcapsule suspensions using two different wall materials compared with the treatment using 15%triadimefon wettable powder in the same dosage of active ingredient.