Spray Pressure
Spray pressure influences spraying effectiveness in crops by 3 ways:
- Pressure influences the spray angle: the higher the pressure the wider the spray angle. If the pressure is too low (below 1,5 bar for flat fans and 3 bar for INJET) the spray angle is not wide enough to ensure full overlap and liquid distribution along the boom.
- The higher the pressure, the smaller the droplets and the more likely they are to be deposited within the upper canopy of the foliage. Smaller drops are also more sensitive to wind movement.
- The higher the pressure, the more surrounding air will be entrained with the spray, which helps larger droplets to penetrate the leaf canopy. The resulting air turbulence within the crop can also increase the deposition of smaller droplets on the underside of leaves, especially when using low output conventional nozzles
Pressures recommended for field spraying with standard and lowdrift nozzles
- Pressures of 2 to 3 bar for normal flat fan and lowdrift nozzles are recommended for most applications.
- Only for well developed dense canopies where penetration is needed - such as weeds that are concealed at the base of a vigorous crop - the pressure could be increased to 5 bar with larger nozzles (03, 04 and above).
Pressures recommended for field spraying with INJET nozzles
INJET nozzles require a minimum of 3 bar to have a full spray angle but can be used up to 8 bars.
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