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GRAIN GUIDE
water flow; increase evapotranspiration and therefore increase water loss; reduce oxygen content
of the water; reduce water quality; habitat for mosquito larvae and bilharzia-bearing snails. There
are biological control agents that are registered for controlling the water hyacinth – these bio-
agents are very effective and must be the first priority in a control programme. Plants can also be
removed manually or mechanically with machinery that moves on the water or is placed on the
banks. However, care should be taken that every part of the plant is removed, as parts that remain
behind will grow again. Various chemicals are registered to control the plant – they can be useful
in combination with mechanical control. The CARA Act classifies water hyacinths as a category 1
plant – landowners must therefore control it.
Pennisetum setaceum (Forssk.) Chiov.
Crimson fountain grass is a thick, erect tussock grass that can
live between 15 and 20 years. The leaves bend down to the
ground and the stems can be between 20 cm and 100 cm
long, but it can be as high as 1,5 m. Crimson fountain grass
occurs in a variety of soil types and it is a weed in disturbed
soil like road reserves, along railway lines and on dumpsites;
it also occurs in grasslands, savannah areas, coastal areas
and even stony areas. It has a well-developed, fibrous root
system and is described as moderately to very drought resis-
tant. It propagates through seeds that can be dispersed by
the wind, water, animals and humans. The negative aspects
of crimson fountain grass are the following: Competitive for
light, water and nutrients, displaces indigenous vegetation;
unappetising; contaminant (seed); reduces the biodiversity
and grazing capacity; increases the risk of fires because of
the high biomass of the grass; reduces the water table level
because it absorbs a lot of water from the topsoil. There
are no biological control agents for this grass. If the plants are small, they can be pulled out by
hand. Mechanical control is not recommended, unless it occurs in dense stands. If it occurs in
dense stands, it can be cut regularly to prevent seed formation – however this must be done on a
monthly or bimonthly basis and it can take up to four years before the grass is under control. This
form of control is therefore very expensive. A chemical is registered to control the grass – it can be
useful in combination with mechanical control. According to the CARA Act crimson fountain grass
is a category 1 plant – the landowner must therefore control it if it does occur.
References
Anonymous. 2010.
Cara legislation made easy
. The Conservation of Agricultural Resources Act, 1983 (Act
No 43 of 1983) (CARA). Department of Agriculture, Forestry and Fisheries.
Henderson, M. Fourie, D.M.C., Wells, M.J. & Henderson, L. 1987.
Verklaarde onkruide en uitheemse
indringerpante in Suid-Afrika.
Departement van Landbou en Watervoorsiening: Pretoria.
Hendesrson, L.2001.
Alien weeds and Invasive plants.
Paarl Printers: Cape Town.
Sharp, D. & Klein, H.2012.
Invasive cacti and succulents.
Department of Environmental Affairs. (Unpub-
lished).
Wells, M.J., Balsinhas, A.A., Joffe, H., Engelbrecht, V.M., Harding, G. & Stirton, C.H. 1986.
A catalogue of
problem plants in Southern Africa
. Memoirs of the Botanical survey of South Africa, No. 53. Department
of Agriculture and Water Supply: Pretoria.
Dr FP Jordaan, Grazing Division, Technology Development and Transfer: Department of Agriculture,
Forests and Fisheries, Potchefstroom
Pennisetum setaceum