Persistence of carbaryl residues in and on unprocessed and processed cauliflower curds.

Carbaryl was applied three times at 15 days interval to cauliflower (Brassica oleracea var. botrytis L.), and its persistence was determined spectrophotometrically at 0, 1, 3, 6, 10, and 15 days after the first and last treatments. In unprocessed cauliflower the prescribed tolerance level for carbaryl residues of 5 ppm was only reached on the sixth day, in processed cauliflower on the third day after application. Pretreatment with washing + boiling/cooking on the other hand led to a considerable decrease of the carbaryl residues already on the day of application. The lower carbaryl values encountered in all variants after the last application are attributed by the authors to a thinning effect due to an increased cauliflower mass.