| Abstract: | The molluscicide N-tritylmorpholine (FRESCON, 1 FRESCON is a Shell trade mark. trifenmorph) is used for the control of the intermediate snail hosts of fascioliasis in livestock. Laboratory and field studies have been undertaken to establish the fate of the compound following its use on pasture. Radiochemical techniques have been used under laboratory conditions to identify the potential degradation products. The major one has been shown to be triphenylcarbinol. Triphenylcarbinol was detected on pastures treated at 0.4 to 0.5 kg/ha under practical conditions but the residues of it and of the parent molluscicide were generally below 0.3 mg/kg within 8 weeks of the application. On the pasture grass half of the initial deposit of N-tritylmorpholine was lost within 1 to 3 weeks and on soils it was lost within 1 to 4 weeks. Residues could not be detected in the tissues of sheep feeding on the treated pasture. Whilst small residues (0.023 mg/kg or less) were detected in the milk of some cows feeding on the pasture soon after application they were absent (below 0.002 mg/kg) in the milk at 10 days or more from treatment. |
