The Influence of Different Adjuvants on the Adhesion Property of 70% Imidacloprid WG on Wheat Leaves

PurposeIn order to study the effects of different adjuvants on the wetting property and retention of imidacloprid water dispersible granule (WG) on wheat leaves, and choose suitable adjuvants to solve the problem of low utilization of existing pesticides.

MethodIn this study, the critical micelle concentration (CMC), the surface tension value (γ_cmc) and wetting property of 15 pesticide adjuvants in the positive and negative sides of wheat leaves were determined by a contact angle/interfacial tension meter. According to the results of γ and contact angles selected 8 adjuvants which had better effects, and added to the imidacloprid WG to analyze the change of wetting property and R_m.

Result Eight kinds of adjuvants could reduce the surface tension and increase the wetting property. The adjuvant 1#, 2# and 4# could reduce the surface tension of the agent by 70.52%- 72.77%, and the surface tension value could be reduced to (21.48 ± 0.15) mN/m, which was lower than the CMC of wheat leaves. And the contact angles on the front and back sides of wheat leaves were less than 60^o, which could be well wetted on wheat leaf surface. The adjuvant 1#, methyl ester sulfonate and SDBS had more obvious effects on increasing the retention, and the amount of retention on the leaves was maximized of the mixture of methyl ester sulfonate and imidacloprid WG.

ConclusionTherefore, the adjustment and addition adjuvants can improve the effect and the utilization rate of pesticides in the process of wheat disease and pest control.