Short and LongTerm Response of Sunflower to Airb

Authors: Swen Follak Frank Walker Karl Hurle

Publish Date: 2005/06/14

Volume: 14, Issue: 5, Pages: 503-512

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Abstract

Wind tunnel studies and a field study were conducted to investigate the impact of the airborne herbicide bromoxyniloctanoate on nontarget plants Sunflowers at the twoleaf stage were used as test plants and exposed for 24 h in a wind tunnel to a range of concentrations of airborne bromoxyniloctanoate Quantum yield of electron transport at Photosystem II φPSII of exposed leaves and leaves developed after exposure plant height days to flower and head diameter were used to determine the short and longterm response of sunflowers to bromoxyniloctanoate Quantum yield of exposed leaves and of the second leaf pair determined 1 h and 2 days after exposure was reduced at concentrations 0449 and 1159 μg/m3 respectively but no effects on further leaf pairs developed after exposure were observed Growth parameters were partly affected when exposed to 1448 μg/m3 In a field study a maize plot was treated with bromoxyniloctanoate and parathionmethyl used as a tracer compound Afterwards potted sunflowers were placed inside the maize plot and at different distances 2 4 8 and 16 m from the treated plot The highest concentrations of bromoxyniloctanoate and parathionmethyl collected in air samples at a distance of 8 m outside of the treated plot were 0100 and 0055 μg/m3 respectively Little of the breakdown product bromoxynil phenol was detected in the air Detectable concentrations of bromoxyniloctanoate and bromoxynil phenol were found only in a few leaf samples whereas parathionmethyl was detected in almost 50 of the leaf samples up to 16 m from the treated plot Quantum yield and growth of sunflower were not affected due to low concentrations of bromoxyniloctanoate in the airFunding for this study was provided by the Deutsche Forschungsgemeinschaft DFG The study was carried out within the scope of the research project “Strategies to Reduce the Emission of Greenhouse Gases and Environmental Toxic Agents from Agriculture and Land use” at the University of Hohenheim Germany

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