Toxicity Assessment of Annona squamosa Oil Cake Using Earthworm Bioassay

An earthworm bioassay was conducted to assess the ecotoxicity of Annona squamosa oil cake amended soil using the species Eudrilus eugeniae. Mortality and abnormal morphology of earthworms exposed to different concentrations of the oil cake, i.e., 10, 100, 112.5, 125 and 150g/kg were examined. Mortality was measured as the ecological end point in the tests. Annona squamosa oil cake was toxic to the earthworm and the severity of the response increased with increasing concentration of the oil cake. The LC₅₀ value showed that the mortality observed was significantly different from the negative control, suggesting that it may be attributed to the effect of addition of Annona squamosa oil cake.