The application of plant protection products plays a key role in the production of most crops. This chapter examines equipment designed to operate with field crops; however, many of the principles discussed will relate to other application systems. The chapter describes features of field crop sprayers for precision agriculture, including control of delivered dose, spatial resolution, matching physical characteristics of sprays to target requirements and minimising drift and exposure of systems outside the treatment area. The chapter includes two detailed case studies focussed on designing and developing a system for spot treatment of volunteer potatoes in vegetable crops and implementing a patch spraying system for applying herbicides to field crops. Finally, the chapter looks ahead to future research trends in this area.