title: Derivation of ozone flux-yield relationships for lettuce: a key horticultural crop.
abstract: Ozone flux-response relationships were derived for lettuce, employing a multiplicative approach to model the manner in which stomatal conductance is influenced by key environmental variables, using a dataset collected during field experimentation in Crete and yield-response relationships derived from parallel open-top chamber experiments. Regional agronomic practices were adopted throughout. Computed versus measured data revealed that the derived model explained 51% (P<0.001) of the observed variation in stomatal conductance. Concentration-based indices were compared with flux-based indices. Analyses revealed a significant relationship between accumulated stomatal ozone flux and yield employing flux threshold cut-offs up to 4 nmol m(-2) s(-1). Regressions employing very low or zero flux thresholds resulted in the strongest yield-flux relationships (explaining approximately 80% (P<0.05) of the variation in the dataset).
authors.affiliation: Environmental and Molecular Plant Physiology, Institute for Research on the Environment and Sustainability, School of Biology & Psychology, Division of Biology, Devonshire Building, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK.
authors.forename: Eleni
authors.initials: E
authors.lastname: Goumenaki
authors.forename: Ignacio Gonzalez
authors.initials: IG
authors.lastname: Fernandez
authors.forename: Antigoni
authors.initials: A
authors.lastname: Papanikolaou
authors.forename: Despoina
authors.initials: D
authors.lastname: Papadopoulou
authors.forename: Christos
authors.initials: C
authors.lastname: Askianakis
authors.forename: George
authors.initials: G
authors.lastname: Kouvarakis
authors.forename: Jeremy
authors.initials: J
authors.lastname: Barnes
mesh_terms: D018556:Crops, Agricultural / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D004780:Environment, Controlled; D004781:Environmental Exposure / Q000009:adverse effects; D006115:Greece; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008954:Models, Biological; D010083:Oxidants, Photochemical / Q000493:pharmacokinetics / Q000633:toxicity*; D010126:Ozone / Q000493:pharmacokinetics / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018570:Risk Assessment / Q000379:methods; D012621:Seasons; D006113:United Kingdom; D014887:Weather
chemical_list: D010083:Oxidants, Photochemical; D010126:Ozone