Evaluation de la contamination des tubercules de manioc ( Manihot esculenta Crantz ) par les pesticides dans la zone cotonnière de Djidja (Bénin) ( Evaluation of contamination of cassava tubers ( Manihot esculenta Crantz ) by pesticides in cotton area of Djidja (Benin) )

In Benin, cultures are submitted to animals attacks and harmful plants. Such situations cause defoliation and destruction of the plants, thus causing huge losses to farmers. To reach the end of such situations, herbicides, insecticides and fertilizers are now being used in higher quantities than past. Even if the use of pesticides to fight weeds and parasites has increased the food crops, it also bads to their contamination. The purpose of this work is to evaluate the level of cassava tubers contamination by the use of pesticides in the township of Djidja (Benin). Nine (09) cassava samples were collected in nine (09) cotton fields in three (03) villages (Zakan Kossossa, Fonkpodji, Aklinme) from 15 th to 19 th March, 2014. The analysis has been done by gas chromatography after extraction and purification. The results show a cassava contamination by glyphosate varying from 0.134 to 0.157 μg/kg, by profenofos varying from 0.115 to 0.128 μg/kg, by acetamiprid varying from 0.095 to 0.151 μg/kg and by cypermethrin varying from 0.133 to 0.153 μg/kg. A regular program must be planned to limit as possible the cassava tubers contamination by pesticides in this township.