The spray nozzles are one of the most important components of pesticide hydraulic sprayer. This study evaluated the droplet spectrum of hydraulic flat fan (standard and low drift) and hollow cone spray nozzles, available in the market, under different working pressures. In laboratory, droplet spectrum, using a real time laser particle size analyzer, was measured with the operating pressure of 200; 300 and 400 kPa, for flat fan, and 400; 500 and 600 kPa, for hollow cone. The results showed that: the droplet spectrum was affected by the nominal flow and by the liquid pressure; the drift potential of standard flat fan and hollow cone spray nozzles was high; the use of low drift nozzles increased the droplet diameter, which was an effective factor in drift reduction, and the technique of laser diffraction provides a robust means of measuring the droplet size produced by spray systems.
spray technology; pesticides; sprayers
