I see both around me every year. Our sprayer plane pilot fancies himself a fighter pilot though, that guy yanks and banks like he's avoiding anti-air....pretty entertaining to watch really.
The drones work a field closer to town, the farmer likes the drones because the field is complicated to spray traditionally, and the drones negate all those problems. They're very big, and very expensive....but not as expensive as the planes....or the traditional sprayers.