Toxicity of herbicides to cyanobacterial isolates
Belma Aslim and Sahlan Ozturk*
Department of Biology, Faculty of
Science and Arts, Gazi
University, Teknikokullar
- 06500, Ankara, Turkey
(Received: December 08,
2007; Revised received: August 05, 2008; Accepted: September 01, 2008)
Abstract: The herbicides most commonly used in Turkey are trifluralin (a,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine),
2,4-D (2,4-dichlorophenoxyacetic acid), and linuron
[3-(3,4-dichlorophenyl)-N-methoxy-N-methylurea]. The
effects of these three herbicides on the growth of 10 threatened aquatic cyanobacterial isolates were tested by using 9-day exposure
experiments at concentrations of 50-200 mg l-1 for trifluralin and 2,4-D and 0.05-1 mg l-1 for linuron. Concentrations of herbicides that elicited a 50%
growth reduction over 9 days (EC50) were 136-882 mg l-1 trifluralin, 122-747 mg l-1 2,4-D,
and 0.002-0.714 mg l-1 linuron. Synechocystis sp. H6 was more tolerant to the
three herbicides than the other isolates of cyanobacteria.
Chroococcus sp. S27, Microcystis
sp. S17, and Synechococcus sp. S24
were the most sensitive to trifluralin, 2,4-D, and linuron, respectively.
There has been increasing awareness about using cyanobacteria
as pollution control agents. The present study indicated that as the
concentrations of the these herbicides were increased,
significant changes were recorded in cyanobacterial
growth rates. Results obtained from this comparative study allow the choice of
suitable herbicides for agricultural practices based on their effects on cyanobacterial growth.
Key words: Herbicides, Trifluralin, 2,4-D,
Linuron, Toxicity, Cyanobacteria
PDF of full length paper is available with
author (* sahlan@gazi.edu.tr)
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