response to ozone and ethylenediurea

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EDU can potentially reduce O3 visible injury in cutleaf coneflower, but may have phytotoxic effects regarding plant productivity. a r t i c l e i n f o ... 1 Present address: School of Forestry and Natural Resources, University of FL, ...... College of.

Environmental Pollution 157 (2009) 840–846

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Environmental Pollution journal homepage: www.elsevier.com/locate/envpol

Cutleaf coneflower (Rudbeckia laciniata L.) response to ozone and ethylenediurea (EDU) Zoltan Szantoi a,1, Arthur H. Chappelka a, *, Russell B. Muntifering b, Greg L. Somers a a b

School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA Department of Animal Sciences, Auburn University, Auburn, AL 36849, USA

EDU can potentially reduce O3 visible injury in cutleaf coneflower, but may have phytotoxic effects regarding plant productivity.

a r t i c l e i n f o

a b s t r a c t

Article history: Received 2 September 2008 Received in revised form 6 November 2008 Accepted 9 November 2008

Cutleaf coneflower (Rudbeckia laciniata L.) seedlings were placed into open-top chambers in May, 2004 and fumigated for 12 wks. Nine chambers were fumigated with either carbon-filtered air (CF), nonfiltered air (NF) or twice-ambient (2) ozone (O3). Ethylenediurea (EDU) was applied as a foliar spray weekly at 0 (control), 200, 400 or 600 ppm. Foliar injury occurred at ambient (30%) and elevated O3 (100%). Elevated O3 resulted in significant decreases in biomass and nutritive quality. Ethylenediurea reduced percent of leaves injured, but decreased root and total biomass. Foliar concentrations of cell-wall constituents were not affected by EDU alone; however, EDU  O3 interactions were observed for total cell-wall constituents and lignocellulose fraction. Our results demonstrated that O3 altered the physiology and productivity of cutleaf coneflower, and although reducing visible injury EDU may be phytotoxic at higher concentrations. Ó 2008 Elsevier Ltd. All rights reserved.

Keywords: Ozone Ethylenediurea Natural vegetation Nutritive quality Rudbekia laciniata L.

1. Introduction Since Middleton (1956) first recognized tropospheric ozone (O3) as phytotoxic, evidence has mounted that it is the most significant regional air pollutant affecting vegetation in the United States (US EPA, 1996, 2006). Concentrations during pre-industrial times averaged

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