Backpack sprayers: These sprayers have a portable tank, worn as a backpack, with a pump, hose, wand and a valve to control the spray. A back pack sprayer can be filled to the capacity of the tank, typically about four gallons, making it ideal for larger jobs. Backpack sprayers have a piston pump that delivers a fine to long-range spray depending upon nozzle adjustment. Slow, steady strokes of the pump handle keeps the spray flowing at an even pressure.
Like compression sprayers, backpack sprayers save money because they minimize the use of the insecticide or fertilizer. With a mist, a little bit goes a very long way. They also are designed to apply material right on target, so you can spot treat just the trouble spots, which is safer for the environment.