FIELD EVALUATION OF RESPONSE TIMES FOR A VARIABLE RATE (PRESSUREâBASED AND INJECTION) LIQUID CHEMICAL APPLICATORS

Abstract

This study investigated the field performance of a ground sprayer for applying chemicals at constant and variableapplication rates with both pressurebased and injection sprayer control technology. Evaluation of the variable rate chemicalapplication system was performed by assessing the field application accuracy through instrumentation of the system tomonitor sprayer chemical flow, sprayer field location, and sprayer speed. The data collected provided information fordetermining the sprayer application rate for each constant and variable rate application.<br><br>The application system produced an average application rate within .2.25% of the desired application rate. The transportlag in the pressurebased variable rate technology is approximately 2 s due to GPS signal lag and control valve response lag.The average active ingredient lag time for the injection variable rate technology is based upon the flow rate of the carrierand ranged from 15 to 55 s. This transport lag varies however for each nozzle.