title: Assisted phytoremediation of mixed metal(loid)-polluted pyrite waste: effects of foliar and substrate IBA application on fodder radish.
abstract: Exogenous application of plant-growth promoting substances may potentially improve phytoremediation of metal-polluted substrates by increasing shoot and root growth. In a pot-based study, fodder radish (Raphanus sativus L. var. oleiformis Pers.) was grown in As-Zn-Cu-Co-Pb-contaminated pyrite waste, and treated with indolebutyric acid (IBA) either by foliar spraying (10 mgL(-1)), or by direct application of IBA to the substrate (0.1 and 1 mgkg(-1)) in association, or not, with foliar spraying. With the exception of foliar spraying, IBA reduced above-ground biomass, whilst direct application of IBA to the substrate surface reduced root biomass (-59%). Trace element concentrations were generally increased, but removals (mg per plant) greatly reduced with IBA application, together with greater metal leaching from the substrate. It is concluded that, in our case, IBA had a negative effect on plant growth and phytoextraction of trace elements, possibly due to unsuitable root indoleacetic acid concentration following soil IBA application, the direct chelating effect of IBA and the low microbial activity in the pyrite waste affecting its breakdown.
authors.affiliation: Department of Environmental Sciences, University of Parma, Viale G.P. Usberti 11/A, 43100 Parma, Italy. teofilo.vamerali@unipd.it
authors.forename: Teofilo
authors.initials: T
authors.lastname: Vamerali
authors.forename: Marianna
authors.initials: M
authors.lastname: Bandiera
authors.forename: William
authors.initials: W
authors.lastname: Hartley
authors.forename: Paolo
authors.initials: P
authors.lastname: Carletti
authors.forename: Giuliano
authors.initials: G
authors.lastname: Mosca
mesh_terms: D001673:Biodegradation, Environmental; D007211:Indoles / Q000494:pharmacology*; D007501:Iron / Q000032:analysis / Q000378:metabolism*; D058955:Metalloids / Q000032:analysis / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D031224:Raphanus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D013440:Sulfides / Q000032:analysis / Q000378:metabolism*; D014866:Waste Products / Q000032:analysis
chemical_list: D007211:Indoles; D058955:Metalloids; D012989:Soil Pollutants; D013440:Sulfides; D014866:Waste Products; C014612:indolebutyric acid; C011342:pyrite; D007501:Iron