Safe Application of Five Pesticides for Cowpeas

The safety of 5 pesticides, abamectin, imidacloprid, spinetoram, carbendazim and tebuconazole, applied on cowpea was evaluated. At the maximum recommended dosage, each of these pesticides was sprayed on the plants 1, 2 or 3 times prior to sampling. Samples of the treated cowpeas were analyzed using the ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) with the positive ion multiple reaction monitoring (MRM) mode. The residues of abamectin, imidacloprid and tebuconazole were found to be lower than their maximum residue limits (MRLs). The residue of spinetoram was below the MRL 2 days after a final application. However, carbendazim required more than 10 days to be considered safe for consumption and was, therefore, not recommended for the application on cowpeas at mature stage.