The rapid and accurate measurement of pesticide droplet distribution in the field is essential for optimal pesticide application. To meet this need, a fast in-situ cloud-based multi-site measuring detector for canopy droplet distribution was developed. As a new approach to droplet deposition measurement in crop protection, it required extensive comparison with the conventional water-sensitive paper (WSP) method, focusing on differences between the two methods in terms of the consistency of droplet parameters in experimental tests. The study showed that the average time for droplet data acquisition was reduced to 35 s. The smallest droplet size detected by this detector was 3.86 μm, which was 13.68 times smaller than the 52.8 μm detected by WSP. When the WSP coverage was below 30%, the Dv0.1, volume median diameter (VMD), and Dv0.9 values measured by the detector and WSP showed similar overall trends. For coverages exceeding 30%, discrepancies increased, and WSP consistently reported larger droplet sizes than the detector, indicating that high coverage amplified the effects of droplet overlap and lateral spreading on size measurements. In parallel, droplet overlap and adhesion on WSP reduced the number of identifiable droplets, resulting in underestimated droplet density, whereas the detector continued to report higher droplet densities under laboratory conditions. In field tests, this detector showed consistency with WSP in the hierarchical droplet distribution in soybean, maize, and cotton canopies. Overall, the developed detector demonstrated promising performance in terms of consistency with WSP, and outperformed WSP in response to droplet estimation and wider spraying coverage estimation.

Paper Linkage:https://doi.org/10.1016/j.cropro.2026.107650