Injection pump frequency effect on sprayer uniformity

The effect of four spray nozzle arrangements and injector pump frequency on uniformity along the spray path was evaluated using collector strings spra yed with fluorescent dye. Injector pump frequency and nozzle type were sign ificant factors affecting spray deposit uniformity differences along the pa th(simulated crop rows). Low pump frequencies affected uniformity along the path less for cone nozzles with large wetted areas than for fan type nozzl es, Injector pump frequencies of 300 rpm resulted in string fluorescence co efficient of variation (CV) values < 10. These CVs were not significantly d ifferent from CV values at pump frequencies of 1725 rpm. Uniformity of dye solution flow among adjacent nozzles(rows)was controlled by micro-tubes wit h injection ports near the spray nozzle at each ron! There were no signific ant differences among mean fluorescence of four strings on different rows e ach injected with dye flow rates of 30, 45 or 60 mL/min (1.0, 1.5 or 2.0 oz /min) through 1.3 nun (0.05 in.) I.D. tubing. A WRK String Analysis System was art acceptable method for determining effects of injection sprayer para meters on application uniformity along and among rows.