Effect of nozzle type and pressure on spray droplet characteristics

Spray nozzles can be considered the most important items of sprayers, and the ideal nozzle-pressure combination plays a major role in the effectiveness of pest control in the field. Spray nozzle manufacturers often develop, and make new alternatives available on the market; however, studies are always important to verify the behavior of tríese new technologies concerning the spectrum of the droplets produced. Therefore, the present study aimed to evaluate the spectrum of droplets generated by four spray nozzles (FC3D 100-02; VP 110-02; TR 110-02 and TT 110-02) under different working pressures (138, 207, 276, 345, and 414 kPa). For this, a factorial scheme in a completely randomized design with four replications was used. The parameters evaluated were volumetric median diameter (VMD), relative amplitude (Span), and the percentage of droplets with a diameter smaller than 100 um (<100 um). The spray nozzles models and the working pressure had a direct effect on the droplet size. Furthermore, there were no significant differences between the TR 110-02 and VP 110-02 models for the percentage of spray volume containing droplets <100 um neither for the VMD. Lastly, the increase of pressure resulted in an increasing linear effect on the Span index for the FC3D 100-02 nozzle.