Regulating the dynamic wetting behavior of pesticide on banana leaves at different growth stages with surfactants.

Background: Pesticide spraying constitutes an essential component of the production and management regimen within banana orchards, extending throughout the entire growth cycle of the banana plants. Exploring the intricate interplay between surfactants, pesticide formulations, and the evolving surface properties of banana leaves throughout their growth stages is critical to the enhancement of pesticide application methods and the elevation of agricultural productivity.

Results: Through investigating the regulatory impact of surfactants on the physicochemical properties of medicinal solutions, this study elucidates the interaction mechanism between the physicochemical properties of pesticides and the surface characteristics of banana leaves. The findings reveal that the energy dissipation rate of pesticide droplets exhibits a natural exponential rise in correlation with the increase in both the We number and the concentration of surfactant present. Comparatively, the adaxial surface of banana leaves demonstrates superior spreading and adhesion properties for droplets than the abaxial surface. Specifically, droplets containing the anionic surfactant sodium dodecyl sulfate on the adaxial surface of banana leaves are found to spread well with a reduced retraction effect. Conversely, the application of the non-ionic surfactant fatty acid polyoxyethylene ether (AEO-3) on the abaxial surface of banana leaves is more beneficial for the wetting and retention of droplets. As banana leaves grow, there is a noted decline in the spreading and retraction properties of droplets. However, droplets have a higher propensity to wet and adhere to the surfaces of mature banana leaves.

Conclusion: To bolster the adherence of pesticide droplets to leaf surfaces, it is imperative to ensure they possess superior spreading properties and a controlled retraction pace. This facilitates an extended period of contact and enhanced stability, thereby optimizing the spray's deposition efficacy. © 2024 Society of Chemical Industry.