Abstract
This thesis addresses both economic and environmental issues by investigating ways to lessen spray drift in agriculture in compliance with ISO requirements. The first part of the thesis explained the Drift phenomena and the Spray Mass Balance Components. The Current methods for identifying pesticide emissions to identify the Target Deposition (Mt), Ground Deposition (Mg), Air Transport (Ma), are reviewed in the first section. We also discussed the current techniques for measuring and controlling spray drift, such as wind tunnel testing, Spray Characterization and Drift Reduction. The experimental component of the thesis takes over in the second section in the which we studied an Oxford Laser N60 shadowgraph system to investigate nozzle spray properties and how to minimize spray drift, this work contributes to the enhancement of sprayer performance models. Initially, we tested three standard hollow-cone nozzles and their anti-drift variants at various pressures and spray cone locations. MATLAB was used for analysis, enabling us to compare and visualize droplet distributions. We later expanded the study by testing five stainless steel flat fan nozzles (Tee Jet, USA). This system covered a range of sprays from Very Fine to Ultra Coarse according to ISO 25358 standards. To ensure the accuracy and dependability of the data, we extended the experiment by utilizing additional nozzles and averaging the outcomes. According to the results, low-drift nozzles and other techniques for minimizing drift are effective, particularly when the proper nozzle type and spray conditions are considered. In the next part we studied the Air Distribution and Spray Performance, the Caffini RAFAL PRO sprayer was used to perform a thorough investigation of airflow patterns and spray efficiency across various fan speed combinations. The study concentrated on maximizing airflow dispersion to improve spray coverage and reduce drift, which directly helps to mitigate the negative impact of agricultural chemicals on the environment. The results provide an alternative solution by targeting the root cause of drift that how droplets behave after leaving the nozzle. Airflow control ensures smaller droplets are less likely to be carried away by wind. To lessen the negative effects of agricultural pesticides on the environment, these findings help to propose new certification processes and offer useful input for creating better sprayer designs. The next part focused on the measurement of air transport (Mt) and ground deposition (Mg) of spray droplets to increase spray coverage and lessen drift, therefore reducing the environmental impact of agricultural pesticides. Key areas for improvement, including the requirement for appropriate airflow at higher velocities and consistent distribution, the findings indicate that whereas Hollow Cone (HC) nozzles contribute to airborne drift with smaller droplets, Air Inclusion (AI) nozzles increase ground deposition by producing coarser droplets. Every test was conducted using established protocols that complied with applicable ISO standards.