Yes. Until recently though, spraying by drone was a near impossible permitting nightmare (now it’s only a minor permitting nightmare) and was inefficient because you needed a Part 107 pilot and a Visual Observer for each individual drone. But, things have gotten better. Before, spray drones over 55lb (the limit for a Small UAS in the US) had to go through an experimental aircraft registration program and be granted a tail number. Now, a select list of drones are authorized for spray operations with a special waiver instead, which is way easier.