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ARS Home » Southeast Area » Miami, Florida » Subtropical Horticulture Research » Research » Publications at this Location » Publication #296910

Title: Nutrient uptake of ornamental plants exposed to arsenic in hydroponic solution

Author
item Reed, Stewart
item Ayala-Silva, Tomas
item Dunn, Christopher - Chris
item GORD0N, GARRY - US Department Of Agriculture (USDA)
item Meerow, Alan

Submitted to: World Journal of Agricultural Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2013
Publication Date: 11/15/2013
Citation: Reed, S.T., Ayala Silva, T., Dunn, C.B., Gord0n, G., Meerow, A.W. 2013. Nutrient uptake of ornamental plants exposed to arsenic in hydroponic solution. World Journal of Agricultural Sciences. Vol 5 No.12;2013 ISSN 1916-9752 E-ISSN 1916-9760.

Interpretive Summary: Arsenic-based chemicals applied on turf-farms, orchards, and around horticultural production structures have contaminated a considerable amount of acreage. A study was undertaken to evaluate iris, switchgrass, tithonia, Coreopsis, Sunflower, and Marigold for their potential use in removing arsenic (As) from contaminated soil. Plants were grown hydroponically in a nutrient solution containing either 0.0, 0.75, 3.75, 5.25 parts per million As. At 5.25 ppmsolution there were no significant reductions in dry weight below that of the controls for iris marigold and sunflower. Dry weights increased slightly in iris and marigold. Improved mineral nutrition was found with these plants and could account for the higher dry weights. The maximum As content in coreopsis and tithonia was reached at 0.75 ppm and for switchgrass at 3.75 ppm As. Iris marigold and sunflower maximum As levels occurred at a solution concentration above 5.25 ppm As, the high level used in this study. In general P decreased and S increased with increasing solution As. Coreopsis and tithonia appear to have a competitive uptake mechanism between arsenate with phosphate. Arsenic tolerance in iris appears to be a result of prohibiting As from accumulation in root tissue.

Technical Abstract: Arsenic-based agro-chemicals have contaminated considerable acreage on turf-farms, orchards, and around horticultural production structures. A study was undertaken to evaluate iris (Iris virginica), switchgrass (Panicum virgatum), Tithonia rotundiflora, Coreopsis lanceolata, Sunflower (Helianthus annuus), and Marigold (Tagetes erecta) for their potential use as arsenic (As) accumulator plants. Plants were grown hydroponically with a modified Hoagland solution containing either 0, 10, 50 or 70 uM As (0.0, 0.75, 3.75, 5.25 mg L-1, respectively). At 5.25 mg As L-1 solution there were no significant reductions in dry weight below that of the controls for iris marigold and sunflower. Dry weights increased slightly in iris and marigold. Improved mineral nutrition could account for the higher dry weights. Maximum shoot As content (mg) for coreopsis and tithonia was reached at 0.75 and for switchgrass at 3.75 mg As L-1 solution. Iris marigold and sunflower maximum shoot As levels occurred at a solution concentration above 5.25 mg As L-1 solution, the high level used in this study. In general P decreased and S increased with increasing solution As. Marigold, switchgrass and sunflower, species that tolerated As at the levels used in this study, had a weak negative correlation between As and Cu concentrations in common. In these species As in hydroponic solution had no effect, or even slightly enhanced, P uptake compared to controls. Arsenic sensitive species coreopsis and tithonia had weak negative correlations between As and K and P in common. Coreopsis and tithonia appears to have a competitive uptake mechanism between arsenate with phosphate. Arsenic tolerance in iris appears to be a result of prohibiting As accumulation in root tissue