Research on dual-charged electrostatic spraying method based on charging of cotton leaves and pesticide droplets

This study proposes an innovative dual-charged electrostatic spraying method based on charging of cotton leaves and pesticide droplets to address the issues of low droplet adhesion rate and insufficient pesticide utilization in spray applications in arid and semi-arid regions. This method charges the cotton leaves with positive charges and the droplets with negative charges through high-voltage electrostatic fields, enhancing the droplet adhesion performance by utilizing the principle that opposite charges attract each other. The study investigated the influence of dual-charged electrostatic spray on the surface charge distribution of cotton leaves, droplet adhesion performance, and pesticide absorption efficiency through designed experiments, including voltage attenuation experiment on the surface of cotton leaves, comprehensive evaluation of droplet adhesion performance and parameter optimization experiment, verification experiment of droplet adhesion performance based on high-speed camera, dynamic monitoring of pesticide residues and observation experiment on stomata. The optimal parameters were 15.396 kV (cotton leaf) and 20.311 kV (droplets), increasing droplet adhesion rate by 26.21 % and reducing droplet volume median diameter by 8.36 % compared to single-charged spraying. The rate of decrease in the electrical conductivity of pesticide residues in dual-charged electrostatic spray was significantly higher than that in single-charged electrostatic spraying, and the pesticide residue was reduced by 32.46 %. The dual-charged electrostatic spray can achieve the coordinated optimization of droplet adhesion rate, droplet volume median diameter, and pesticide absorption efficiency by cotton leaves, providing theoretical support for precision agriculture and is expected to promote the development of electrostatic spraying technology towards high efficiency and precision.