parameters of the nozzles are different from the European nozzles. In this study, one series of the drift reduction nozzles under different nozzle-pressure combong>inong>ations were tested ong>inong> the wong>inong>d tunnel ong>inong> order to estimate the drift reduction performance ong>basedong> on one reference spray. Additionally, the ong>inong>fluences of the nozzle size, pressure and height on the DPRP values were also ong>inong>vestigated. 2. Materials and methods 2.1 Wong>inong>d tunnel parameters and measurong>inong>g protocol The wong>inong>d tunnel experiment was carried out ong>inong> the Bio-oriented Technology Research Advancement Institution (BRAIN), Saitama city, ong>Japanong>. The dimensions of the wong>inong>d tunnel were illustrated ong>inong> Fig. 1. To obtaong>inong> the vertical deposits of each nozzle-pressure combong>inong>ation under different nozzle heights at the same time, the nozzle was ong>inong>stalled at 1.2m above the floor and 6 polyethylene long>inong>es (V 1 ~V 6 ) were placed horizontally across the wong>inong>d tunnel 2m downwong>inong>d with the heights from 0.7m to 1.2m at an ong>inong>terval of 0.1m, respectively. A tracer (Solium fluoresceong>inong>, 200ppm) and a non-ionic surfactant (Tween 20, 0.1%) were used ong>inong> this study. After sprayong>inong>g, the collector long>inong>es were washed ong>inong> 100ml de-ionized water and the liquid was taken to measure the tracer concentration value. The volume of the spray liquid deposited on each collector long>inong>e was obtaong>inong>ed by calculation. FIGURE 1: The dimensions of the wong>inong>d tunnel and the sketch of drift potential measurement ong>inong> the wong>inong>d tunnel by usong>inong>g polyethylene long>inong>es Table 1 showed the nozzle ong>inong>formation and environmental parameters of the nozzles ong>inong>vestigated ong>inong> this study. The Hypro ISO F 110 03 standard flat fan nozzle with a nozzle pressure of 0.3MPa and a nozzle height of 0.5m was used as the reference spray. The YAMAHO KIRINASHI ES nozzles were recommended to use with a nozzle height between 0.3~0.4m. The spray time of the nozzle-pressure combong>inong>ations was 10s when the flow rate was above 0.8L mong>inong> -1 and 20s for the other combong>inong>ations.
TABLE 1: Overview of the ong>inong>vestigated nozzle-pressure combong>inong>ation and the environment parameters ong>inong> the drift experiment ong>Nozzleong> ong>inong>formation Environment parameters  Notation  Flow rate  , L mong>inong> -1 Pressure, MPa Air temperature, ℃ Water temperature, ℃ Relative humidity, % HS03-0.30 1.20 0.30 22.4 20.6 57.3 ES05-1.00 0.35 1.00 23.7 21.6 50.7 ES05-1.50 0.43 1.50 27.0 22.8 46.7 ES06-1.00 0.51 1.00 25.4 22.0 53.3 ES06-1.50 0.62 1.50 25.6 22.2 43.7 ES07-1.00 0.68 1.00 27.0 22.8 37.7 ES07-1.50 0.83 1.50 21.8 20.7 78.0 ES08-1.00 0.90 1.00 22.2 20.7 71.7 ES08-1.50 1.10 1.50 26.5 22.0 42.7 ES09-1.00 1.13 1.00 25.8 21.2 45.3 ES09-1.50 1.39 1.50 23.1 31.7 42.5 ES10-1.00 1.41 1.00 24.3 21.0 49.0 ES10-1.50 1.73 1.50 17.5 17.6 66.7 ES11-1.00 1.69 1.00 17.4 17.5 70.3 ES11-1.50 2.07 1.50 22.0 19.3 60.0  HS03, Hypro ISO F 110 03 standard flat fan nozzle; ES, YAMAHO KIRINASHI ES nozzle;  The flow rate data were cited from manufacturer data;  The values of the environment parameters were obtaong>inong>ed by averagong>inong>g the value of three repetitions. 2.2 Index calculation and nozzle drift ong>classificationong> In this study, the DIXRP value was calculated to estimate the drift reduction performance of the ong>inong>vestigated nozzle-pressure combong>inong>ations (Herbst, 2001). In the calculation process, the nozzle heights were 0.5m for the reference spray while the nozzle heights were 0.4m and 0.3m for the ES series nozzles ong>basedong> on the manufacturer recommendation. The details of the calculation equations could be found ong>inong> the above reference. The virtual floors (h=0m) ong>inong> the ong>inong>dex calculation were assumed to be 0.6m, 0.7m and 0.8m above the floor of the wong>inong>d tunnel correspondong>inong>g to the three nozzle heights, respectively. Thus, the nozzle heights which equal the vertical distance between the nozzle and the lowest collector long>inong>e were 0.5m, 0.4m and 0.3m. The nozzle drift ong>classificationong> for the nozzle-pressure combong>inong>ations ong>inong>vestigated was carried out followong>inong>g the methods adopted by German Federal Biological Research Centre for Agriculture and Forestry Braunschweig (BBA) (Herbst, 2001).