First I have to say I really don't like chemical herbicides / pesticides but farmers do what they believe they have to do...
The neighbour contracted an aerial drone sprayer because the paddock was too muddy for the tractor. I am somewhat fascinated by drones so wandered over with my camera. It looked better in motion to the naked eye than the stills...
[Edit] This thing was about 2mtrs across from one set of props to the other.