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Cedergreen N 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1099-1104
The herbicide, glyphosate, has been shown to stimulate growth in a range of species when applied at doses of 5-60 g a.e. ha−1, corresponding to realistic spray drift events. This study investigates growth of shoot parameters over time to detect whether the glyphosate induced growth increase was sustained and had a final effect on reproduction. The results showed that an actual biomass growth rate increase took place within the first week after spraying with glyphosate doses <60 g a.e. ha−1. This initial growth boost kept treated plants larger than untreated plants for up to six weeks, but at harvest there was no significant difference between control plants and treated plants. Possible effects of glyphosate hormesis on the competitive ability of spray drift affected plants are discussed. 相似文献
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Katrine Banke Nørgaard Nina Cedergreen 《Environmental science and pollution research international》2010,17(4):957-967
Background, aim and scope
The ergosterol biosynthesis-inhibiting (EBI) fungicide prochloraz can enhance the effect of other pesticides in a range of animal species. Approximately 50% of the fungicides used in Denmark are EBI fungicides. Hence, if they all have synergising potential, a risk assessment of pesticide mixtures based on additivity might not suffice. This study investigates the synergising potential of six different EBI fungicides representing the imidazoles (prochloraz), the triazoles (epoxiconazole, propiconazole and tebuconazole), the piperidines (fenpropidin) and the morpholines (fenpropimorph) together with the pyrethroid insecticide alpha-cypermethrin. 相似文献3.
An isobole-based statistical model and test for synergism/antagonism in binary mixture toxicity experiments 总被引:4,自引:0,他引:4
Helle Sørensen Nina Cedergreen Ib M. Skovgaard Jens C. Streibig 《Environmental and Ecological Statistics》2007,14(4):383-397
Synergism and antagonism are often defined in relation to the model of Concentration Addition (CA). Hence, it is vital for
the conclusion of mixture toxicity studies to be able to test whether an observed deviation from CA reflects a true deviation
or whether it is simply due to random variation. In this paper we consider a non-linear regression model for the classical
ray designs for binary mixture experiments. The model combines dose–response curves for each mixture in the experiment with
an isobole model, describing possible deviations from CA. The method allows us to test whether the chosen isobole model is
reasonable for the data and to test the hypothesis of CA. Furthermore, it provides us with a measure of the degree of synergism/antagonism.
The method is flexible since both the dose–response relationships and the isobole model can be chosen arbitrarily. We demonstrate
the use of the method on datasets where combinations of pesticides are tested on a floating plant, Lemna minor, and an algae, Pseudokirchneriella subcapitata. Furthermore, we conduct a simulation study in order to explore the power with which a specific deviation from CA can be
distinguished in different test-systems. 相似文献
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