The Effects of Adjuvants on the Wetting and Deposition of Insecticide Solutions on Hydrophobic Wheat Leaves

Pesticide droplet deposition determines the efficacy of pesticide solution and is a critical process in pesticide application. Adding spray adjuvants can improve droplet deposition to a certain extent, but there are currently many types of adjuvants with different properties. The improper selection or unreasonable use of adjuvants may be counterproductive, increasing the loss of pesticides or causing crop damage. In this study, the adjuvants methylated plant oil (Beidatong), alkoxy modified polytrisiloxane (Silwet408), hyperbranched fatty alcohol ether modified polymer (ND500), and polymers adjuvants (G2801) were selected through surface tension, contact angle, the determination of the maximum retention (Rm) and point of run-off (POR), and field deposition to explore the effect of adjuvants on the wetting and deposition performance of pesticides on wheat leaves. Compared with Beidatong and G2801, Silwet408 and ND500 could significantly reduce the surface tension of pesticides and greatly promote the wetting properties on wheat leaves, but Rm and POR value on wheat leaves were reduced. The field test results also showed that the deposition amount of the adjuvant Silwet408 and ND500 on wheat was slightly lower than that of the adjuvant Beidatong and G2801. Studying the effects of adjuvants on the wetting and deposition properties of insecticide solutions can provide practical guidance for the use of adjuvants.