Port Owen dredger collecting
water hyacinth with a boom.
The problem is that often there are submerged trees that can damage
the boats. The alien vegetation that is found in the Berg river is of
particular interest. Hundreds of Blue gum trees are found in and around
the river. They provide natural barriers for the water hyacinth to pack
and form huge beds of impenetrable growth.
Photograph by John Hoffman for
e-mail permission to use it from
There is a small beetle that has been imported from Australia. This beetle is known as the
snout beetle. It is one of the main water hyacinth fighters. It burrows
into the spongy stem of the plant which stresses the plant which then sink and die.
This beetle has proved to be very effective in the tropical areas.
This is a sap sucking mirid used in South Africa. The females inserts
their eggs into the leaves of the water hyacinth. When the nymphs hatch
they eat away at the undersides of the leaves of the water hyacinth.
They develop into adults and can live for about 50 days. The adults also
feed on the water hyacinth. The leaves turn brown and the plant becomes
stressed and dies because of these insects.
Biological control of water hyacinth does not seem to be working well on the West Coast
of South Africa . The farmers believe it is because not nearly enough
beetles have been sent to this area. The small number released have not
bred well and so the impact is minimal.
of crops on the West coast of South Africa
This method is of course very effective. Many different poisons are
used including a product called "Roundup"
A very dangerous chemical called 2,4-D has been used to kill off
When 2,4-D is used, it destroys the Water Hyacinth and everything
else in that environment. There is another chemical used called
Glyphosate which works much more slowly but it creates less environmental
We do not agree with the use of chemicals as there are many side effects
to both the environment and to man.
Did you know?
2,4-D was one of the major ingredients in "Agent orange," This
was used in chemical warfare in Vietnam. It destroys and kills plants
and trees. 2,4-D has been banned in South Africa, Zimbabwe and Sudan because it is
such a health hazard.