Details

Autor(en) / Beteiligte

• Cedergreen, Nina
• Andersen, Lone
• Olesen, Charlotte Frihauge
• Spliid, Hans Henrik
• Streibig, Jens Carl

Titel

Does the Effect of Herbicide Pulse Exposure on Aquatic Plants Depend on K sub(ow) or Mode of Action?

Ist Teil von

• Aquatic toxicology, 2005-02, Vol.71 (3), p.261-261

Erscheinungsjahr

2005

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• Pulses of high concentrations of herbicides in surface waters can occur due to runoff, spray drift, or leaching. The effects of three hour pulses of six different herbicides that had three different modes of action and different octanol-water partition coefficients (K sub(ow)0 were investigated in duckweed. The range of the log K sub(ow) was -4.6 to 5.2. Imazamox and metsulfuron-methyl inhibit acetolactate syntase, terbuthylazine and diquat inhibit photosynthesis, and pendimethalin and propyzamide inhibit assembly of microtubules. Results showed that for all herbicides except diquat and terbuthylazine, the same effect as four days of exposure could be shown after three hours of exposure to concentrations that were ten times greater than the four day dose. For the other two compounds, 100 times more herbicide was needed to induce an effect compared to the concentration needed to induce the effect after four days of exposure, although terbuthylazine showed adverse effects on photosynthesis within one hour of exposure. However, photosynthesis recovered quickly. For the enzyme and microtubule assembly inhibitors, recovery was much slower.