A Sustainable Pesticide Application Strategy Based on the Wettability Characteristics of Plant Leaf Surfaces

Abstract

Due to long-term evolution and adaptation to the natural environment, the surfaces of plant leaves have developed hydrophobic microstructures or functional characteristics around stomata. These adaptations ensure the long-term stability of stomatal function under rainy or highly humid conditions. However, such hydrophobicity also poses challenges for agricultural practices, particularly in pesticide application, where poor wettability of leaf surfaces often reduces droplet adhesion and pesticide efficiency. Therefore, identifying the relatively more hydrophilic regions of plant leaves is essential for improving pesticide deposition and utilization. In this study, we conducted a comparative analysis of the morphology and wettability of both the upper and lower surfaces of Silver Maple leaves. The results revealed that the lower surface exhibits significantly stronger hydrophobic properties than the upper surface, which can be attributed to the presence of micro-nano hierarchical roughness on the epidermis. These surface structures effectively enhance water repellency and droplet rolling, thereby protecting the leaves but simultaneously reducing the adhesion of aqueous pesticide solutions. Our findings provide new insights into the relationship between leaf surface microstructure and wettability, and highlight the importance of targeting more hydrophilic sites on leaves for efficient pesticide application. This study not only contributes to improving the precision and effectiveness of pesticide usage but also supports sustainable agricultural development by reducing chemical waste and environmental pollution.