Field Evaluation of Calibration Accuracy for Pesticide Application Equipment

Abstract

ABSTRACT A1979 field survey was conducted in Nebraska and western Iowa of 152 private and commercial pesti-cide applicators. The survey showed that only one out of every four cooperators were applying pesticides within 5 percent of their estimated application rate. Incorrect calibration accounted for the greatest amount of applica-tion errors and ranged from nearly 60 percent underap-plication to more than 90 percent overapplication. Uniformity of the application was also in error. The coef-ficient of variation among nozzles for liquid applicators averaged 21.9 percent whereas granular applicators averaged 4.7 percent among boxes. The survey also showed that the most common method of calibration was the Known Area method, but no statistical relationship between this method and accurate applications was measured.