**4. Conclusions**

Following previous findings related to the droplet size increase in pneumatic spraying, a study was carried out to check the influence of modifications in the liquid hose position with respect to the air spout. In both tested nozzles, namely cannon and hand types, the air speed decreased consistently from the inner to the outer part of the spout, with higher decrease outside of the spout.

Therefore, the strategy to move the liquid release hose to outer positions with respect to the conventional one is as an e ffective way to substantially increase the droplet size spectra generated by pneumatic sprayers. This e ffect was certified by the Volume Median Diameter (D50) increase equal to 280% for the cannon and 270% for the hand spouts just by changing the liquid hose position from the inner to the outermost spout position. Similar results were obtained for D10 and D90. In particular, the variation of liquid hose position from conventional to extreme out of spout position (XP) allowed to vary the spray quality generated from very fine (VF) to coarse (C)/very coarse (VC), giving farmers a wide range of options during the spray application. The droplet driftability, measured by the V100 parameter, decreased with the increase of the liquid hose distance from its original position. This suggests that when the liquid hose is in the extreme outer position, the pneumatic nozzle behaves similarly to a hydraulic drift reducing nozzle.

The findings of this study could significantly help in reducing the spray drift in pneumatic spraying just by slightly modifying the spray nozzle, which could have important practical implications. For the first time it is possible to design a device that gives farmers and technicians the possibility to match the drift-reduction environmental requirements using pneumatic sprayers for 3D crops, balancing at the same time the treatment specifications for every spray application.

**Author Contributions:** Conceptualization, M.G., A.M.F., P.M. and P.B.; methodology, M.G., A.F.M., P.M. and P.B.; validation, M.G., A.F.M. and P.M.; formal analysis, M.G. and A.F.M.; investigation, M.G., A.F.M., P.M. and F.G; resources, P.B.; data curation, M.G. and A.F.M.; writing—original draft preparation, M.G. and A.F.M.; writing—review and editing, M.G., A.F.M., P.M., P.B and F.G.; visualization, M.G.; supervision, M.G., P.B. and F.G.; project administration, F.G.; funding acquisition, P.B.; All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** The authors would like to thank CIMA S.p.a. (Pavia, IT) for providing the spouts used in the experimental work.

**Conflicts of Interest:** The authors declare no conflict of interest.
