The use of spray nozzles that provide a homogeneous covering with uniform droplet spectrum is important to obtain an efficient pesticide application, without damage to the environment. Thus, the principal aim of this work was to evaluate the technical characteristics of four hydraulic spray nozzles available in the market, under different working pressures and positions in relation to the objective, seeking to supply indicators for a correct selection of spray nozzles. In a controlled atmosphere, the following parameters were determined: distribution profile, the flow, the coefficient of variation of the nozzle distribution, the volume median diameter, the number median diameter, the homogeneity coefficient, and the percentage of droplets smaller than 100 mum. In a general way, the nozzles presented satisfactory levels of distribution uniformity, working with a pressure of 300 kPa and 50 cm of height. The appraised nozzles, in agreement with the used methodology, presented a volume mode diameter of 340 mum, and the droplets spectrum was shown to be within the recommended patterns. The homogeneity coefficient of the droplet size was better with low flow and low pressure.
droplets; spray nozzles; application technology
