Hewitt, AndrewRoten, RoryGiles, D. K.Bachalo, W.Connell, Robert J.2020-06-072013https://hdl.handle.net/10182/12031A new approach is proposed for modeling droplet deposition downwind of spray application areas for almost any pesticide application technique using initial field measurements of the size/ velocity profile of the spray which is still airborne downwind of the intended target. A field Phase Doppler Inteferometer (PDI) system has been developed for measurements of these sprays at different heights under field conditions. The size and velocity data can then be input to existing modeling algorithms such as the AGDISP Lagrangian solution code which then tracks particle transport, evaporation and deposition downwind of the spray release point. Libraries of data for various spraying systems can be linked with the model for future spray drift exposure risk assessments that will facilitate decision-making on safe-ty measures such as application recommendations or the size and location of no-spray buffer zones for specific pes-ticides and non-target sensitive areas. The present paper describes this process and provides examples of data meas-ured in field studies using the modified PDI system. The work is ongoing and the present paper is aimed at describ-ing the development of the sampling systems through field studies in New Zealand and the USA. Future research will focus on comparison of modified AGDISP model predictions of spray deposition using measured droplet size/ velocity data against actual field study deposition data in several application scenarios and crop types.4en© The authorsmodelingdroplet depositionPhase Doppler Inteferometer (PDI)pesticide spraysConference Contribution - published