Abstract

                                Bioassay using cucumber growth was utilised to detect the residues of some common herbicides in soil. The experiment was conducted under pot culture conditions in alluvial (entisol), black (vertisol) and red (Alfisol) soils. Atrazine, oxadiazon, oxyfluorien and ter- butyrn inhibited the germination, plant height and dry matter production of cucumber. The red soil exhibited acute toxicity even at lower concentration and the LD 50 of these herbicides were lower than the alluvial and black soils. The detection of residues in the unknown soil can be easily computed from the derived quadratic equations.

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