heavy metals extraction potential of sunflower (helianthus annuus) and canola (brassica napus)

phytoextraction is a remediation technology that uses plants to remove heavy metals from soil. the success of a phytoextraction process depends on adequate plant yield (aerial parts) and high metal concentrations in plant shoots. a pot experiment was conducted to investigate the combination effects of plants [sunflower (helianthus annuus) and canola (brassica napus)] with soil treatments (manure, sulfuric acid and dtpa). treatments, included two plants and seven soil treatments, which were applied baeed on a completely randomized factorial design. three replicates were used for each treatment.. the largest shoot dry weight biomass production occurred in manure treatments for both plants. the maximum shoot concentrations of pb and zn were 234.6 and 1364.4 mg kg-1 respectively in three mmoles dtpa kg-1 treatment of sunflower. furthermore the results showed that sunflower had a higher extracting potential for removal of pb and zn from polluted soil.