In an attempt to refine calibration procedures for greenhouse spray chambers, the effects of an herbicide adjuvant, operating pressure, and travel speed on the static and dynamic spray patterns of single flat-fan hydraulic nozzle tips were studied. The volume output in the central 15 cm of the spray pattern (where target plants would ordinarily be positioned) was used as an indicator of the relative dosages received from both a tapered flat-fan tip (8001 VS) and an even-spray tip (8001 EVS). All tested variables significantly altered the spray pattern. Specifically, dynamic spray patterns differed from static patterns, and speed of travel affected the dynamic pattern for both tapered and even flat-fan sprays. Increasing the travel speed from 0.375 to 0.75 m/s reduced spray deposit in the central 15 cm of the spray pattern by up to 19% for water, and by up to 34% for water containing 0.1% v/v nonionic surfactant. Increasing surfactant concentration to 1% decreased the magnitude of the speed effect. Higher pressure sprays tended to reduce the effect of increased travel speeds. These results show that changes in physicochemical properties of the spray solution as well as air turbulence introduced by nozzle movement can affect the pesticide dosage to which a target plant is exposed in a spray chamber. For proper treatment comparison, delivery systems for greenhouse spray experiments should be calibrated with end-use spray liquids, operating pressures, and nozzle travel speeds.