Pesticide residues on lettuce (Lactuca sativa L.) in Cundinamarca-Colombia

Lettuce is Colombia's most widely cultivated leafy vegetable, but in the absence of good agricultural practices, there is the risk of some pesticide residues that affect its safety and quality. This work aimed to identify the pesticides used by farmers for the lettuce crop, the iceberg variety (Lactuca sativa var. capitata), in some municipalities of Cundinamarca (Colombia) and to investigate their residues by sampling and analysis. The farmers reported in the survey 44 active ingredients, most fungicides (54%), while the laboratory analysis showed 23 chemical compounds (52% insecticides, 39% fungicides and 9% herbicides). In addition, dithiocarbamates, procymidone and some organophosphates were among the active ingredients that exceeded the maximum residue limits (MRLs). About 80% of the identified pesticides were not registered with the regulatory entity Instituto Colombiano Agropecuario (ICA) for their use in lettuce, but some were in commercial products legally registered in Latin American and Caribbean countries.