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The environmental toxicity
of Dicerothamnus rhinocerotis and Galenia africana
E. J. Pool*, J. A. Klaasen and Y. P. Shoko
Department
of Medical Bioscience, the University of the Western Cape,
Private bag X17, Bellvile, 7535, South Africa.
*Corresponding author. E-mail:
epool@uwc.ac.za. Tel.:
+2721 959 3535.
Fax: +2721
959 3125.
Accepted 22
June, 2009 |
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Over the years the use of pesticides has greatly increased.
This in turn has lead to concern about the adverse effects
that the pesticides may have on non-target organisms in the
environment. Due to increasing awareness there is great
pressure to reduce the use of synthetic pesticides. An
alternative to the use of synthetic pesticides is the
exploitation of natural botanical products with pesticidal
potential. Dicerothamnus rhinocerotis and Galenia africana
are plants, indigenous to South Africa, with fungicidal
properties against a fungal pathogen that causes grey-mould
rot on a wide range of agricultural produce. In this study a
series of acute toxicity tests were conducted to estimate
the potential environmental effect of D. rhinocerotis and
G. africana. The acute toxicities of the plants were determined
using the species
Daphnia pulex, Selenastrum capricornutum, Vibrio fischeri
and
Poecilia reticulata as bio-indicators. Results obtained
showed that
G. africana had higher toxicity units than
D. rhinocerotis, thus showing that
G. africana is more toxic to the aquatic
environment
compared to
D.
rhinocerotis.
Key words:
Pesticides, Galenia africana,
Dicerothamnus rhinocerotis,
acute toxicity. |
