Wetting and adhesion behavior on apple tree leaf surface by adding different surfactants.

OBJECTIVE: This study was conducted to investigate the wetting behavior of different surfactant solutions on the leaf surfaces of apple during the fruit formation stage. METHODS: Five surfactants, including C12E5, Tween-20, Triton X-100, DTAB, and SDS were evaluated in this study. The contact angle, surface tension, adhesion tension, work of adhesion, and solid-liquid interface tension of droplets on the leaf surface were determined by the drop method. RESULTS: The results showed that the nonionic surfactants C12E5 and Triton X-100 had better wetting effects than other surfactants. Moreover, when the concentration of C12E5 and Triton X-100 was 1 × 10-3 mol/L, the leaves reached a completely wet state. Toxicity measurement showed that the incubation rate of Carposina niponensis eggs decreased gradually with increasing content of C12E5 or Triton X-100. Additionally, field efficacy analysis showed that adding C12E5 or Triton X-100 significantly improved the beta-cyfluthrin 3% water emulsion (EW) against C. niponensis. CONCLUSIONS: These results indicate that the surfactants C12E5 and Triton X-100 can significantly improve pesticide application, which will be helpful for reducing pesticide use and developing new pesticides.