This company sells a range of drones for spraying crops (Agras series) and also for mapping areas. There is a lot of technical information on their web site about the performance of the various models.
The drones available can spray crops on flat terrain or slopes and can also spray fruit crops.
Up to 25.000 EUR
https://ag.dji.com/case-studies
7 m/s
1 ha / 6 min, or 10 ha/hour
Operator needed