A mobile plant service system for treating plants in a crop growing area includes a transport device deployed for moving across the crop growing area. A spraying apparatus mounted to the transport device for delivering an atomized liquid to the plants in the crop growing area includes a plurality of spray nozzles, a pressure vessel for storing compressed air, a pressure regulating valve assembly, and a receptacle containing a liquid. A flow controller actuates the pressure regulating valve assembly to allow the flow of a controlled release of compressed air to the plurality of spray nozzles at a spray out pressure.
