Which factor does NOT directly influence the flow rate of the sprayer?

The flow rate of a sprayer is primarily influenced by factors that directly affect the delivery of the liquid being sprayed. Nozzle size is critical because it determines how much liquid can exit the nozzle at a given time, thus affecting the flow rate directly. Aircraft speed influences the amount of time the spray is applied over a surface; faster speeds can lead to lower application rates per unit area if the flow rate stays the same. Pesticide viscosity affects how easily the liquid flows through the system; more viscous liquids will flow slower, affecting the overall flow rate.

Field geography, while it can impact operational decisions and safety, does not have a direct effect on the physical flow rate of the liquid coming from the sprayer. Terrain and landscape may require different strategies or adjustments in application but do not change the fundamental mechanics of how fluid is dispensed from the nozzle. Thus, it is the factor that does not directly influence the flow rate of the sprayer.