Drone use is expanding rapidly in both the U.S. and Asian agricultural markets. At the AgriBusiness Global LIVE! Drone Update webinar four industry experts explored the future of drone technology and emerging formulation opportunities for this fast-growing ag tech sector.

From the 562 registered attendees, several questions were posed to our panelists. Here, Rene Haensel, Technical Director Agriculture & Global Senior Expert for Evonik, and Arthur Erickson, CEO/Co-Founder from Hylio, answer questions from participants of the live broadcast.

ABG: Are nano or high-performance liquids a solution for the drone spray issue?

Rene Haensel (RH): In Europe, we have in some countries already to confirm that the adjuvants are free of nanotechnology. There is seen a danger of nano particles. I see this can be a future, critical issue for drones in general.

The use of high-performance liquids is a solution. Products that show some multifunctional properties are being used in conventional application, but also for drones. I will mention here polyether-trisiloxane technology, which is extremely low-surface tension of water and therefore excellent adhesion and retention of spray droplets and also spreading, can be blended with substances which provide drift control. One can use here conventional technology for blending like some oils or polymers like guar gums, polysaccharide but also sophisticated technology based on insoluble droplets with very low surface tension.

ABG: Does the drone propeller contribute to drift?

Arthur Erickson (AE): The drone propellers actually mitigate the drift. This is due to the fact that their downwash is driving the majority of the particles downward into the target crop as opposed to allowing the ambient wind conditions or temperature inversions to carry the spray away (i.e. drift).

The vortices created by the propeller wingtips do recirculate some portion of the spray causing temporary upward moving of some of the particles, but the aggregate behavior of the spray is still downward into the target crop.

ABG: What about pulse width modulation (PWM) for drift control?

AE: Generally speaking, there are many other factors in drone spraying that have much stronger influences on the drift behavior than the PWM behavior of the nozzles.

The drone’s speed and altitude have a major effect on overall spray deposition performance and also highly important is the spatial placement of the nozzles in relation to the rotors (mounted closer to the center of the rotor axis = better drift control).

PWM is useful insofar as it is used to consistently produce droplets of a certain size. We actually do use PWM controls for our spray systems on our drones, but the overall effect is simply maintaining a consistent pressure and flowrate as defined by the operator. We happen to use PWM to do this in our system, but there are other ways to maintain consistent pressure/flowrate, which would correspond to some desired droplet size.

Read more at AgriBusiness Global.