The Effect of Diluent Oils on the Electrostatic Atomization of Some Insecticides

Concern for environmental contamination, operator safety and economics has led to a desire to apply pesticides in as low an application volume as possible without loss of efficiency of the application device or pesticidal activity. One way to accomplish this is by use of electrostatic applicators, some of which require oil instead of water as the pesticide diluent.

The objective of this study was to determine the effect of different concentrations of Ambush 2E, Capture 2E, and Asana XL, mixed with Terra Prime Oil II, on the droplet spectra produced by an electrostatic atomizer. Each mixture was atomized using a single ligament nozzle. Droplet spectra were determined using an Aerometrics PDPA-100D phase/Doppler particle analyzer.

Ambush had the greatest effect on oil atomization. Ambush at 10% concentration gave the best atomization characteristics across the most suitable voltage range. Increasing the concentration of Capture gave a decrease in D_v0.5. With Capture at 20%, stable atomization was only attainable between 15 and 30 kv. Asana XL showed less change in D_v0.5 than either Capture or Ambush.

The resistivity of all the test mixtures was measured and was shown to be a key parameter in determining the potential atomization characteristics of the spray cloud.