Pb-phytoextraction potential by castor beans in soil contaminated

The present work was developed with the objective to evaluate the accumulation of Pb in plant tissue of castor bean (Ricinus communis L.) in contaminated soil and investigate the potential for soil remediation. The experiment was carried out in a greenhouse at the Faculty of Agricultural Sciences/UNOESTE - Presidente Prudente/SP. Plants were grown in pots with a capacity of 9 dm(3) of soil. The treatments were in addition to the vessels of 18.8 mg kg(-1), 37.5 mg kg(-1), 75 mg kg(-1), 150 mg kg(-1), 300 mg kg(-1), 600 mg kg(-1) and 1200 mg kg(-1) in the form of Pb (Pb(NO3)(2)). Treatments were arranged according to completely randomized design with three replications. Samples of soil and plant tissue were collected ninety days after sowing for the quantification of mass of dry matter of shoots and roots, and for determining the accumulation of lead in tissues of both species. The parameters were subjected to analysis of variance evaluating the effect of treatments by the Tukey test at 5% level of probability. The results presented by significant F-test were submitted to polynomial regression. The castor beans had a higher accumulation of Pb in roots, there was a decrease in plant growth due to a reduction of mass of dry matter of shoots and roots with the gradual increase of the concentration of Pb in soil and the addition of 1200 mg kg(-1) Pb in soil was more effective in reducing the growth of castor bean.