Maize plants exposed to atrazine at temperatures ranging from 10°C to 30°C showed increased hydroxylation of atrazine to form the non-toxic hydroxy-atrazine metabolite as temperature increased to 25°C, above which hydroxylation decreased again. When exposed to 12 ppm atrazine, accumulation of atrazine occurred in roots and shoots of maize plants under all temperature-regimes. The results presented show that hydroxylation of atrazine does occur in roots and shoots of maize plants. Therefore, in the case of insufficient atrazine hydroxylation in the roots, with resulting accumulation, atrazine will be transported via the transpiration stream to the shoots where subsequent hydroxylation will take place.S. Afr. J. Plant Soil1986, 3: 115–118