INTERCEPTION AND PERSISTENCE OF PARATHION AND FENVALERATE ON COTTON PLANTS AS A FUNCTION OF APPLICATION METHOD

Parathion (O,O-diethyl O-4-nitrophenyl phosphorothioate) and fenvalerate [(RS)-alpha-cyano-3-phenoxybenzyl (RS)-2-(4-chlorophenyl)-3-methylbutyrate] were applied by controlled droplet applicators (CDAs) and conventional hydraulic nozzles in refined soybean oil, soybean oil + water, or water, to mature cotton plants (Gossypium hirsutum L.) as ULV (ultra-low volume, < 5 litre ha-1), VLV (very low volume, 5-50 litre ha-1), or LV (low volume, 50-200 litre ha-1) carrier rates. The use of CDA or soybean oil applied as ULV and VLV sprays did not produce greater deposition or persistence for either insecticide during the 49-h test period following application. In general, insecticide persistence was greatest when applied with water or soybean oil + water as LV sprays using the conventional TX8 hydraulic nozzle.