The troubled Limpopo River area is in trouble again — this time from the effects of herbicides used by contractors employed by the SADF, writes Stephanie Dippenaar
ILLEGAL and dangerous herbicides — used by South African Defence Force contractors to control 70km of sisal fence along the Zimbabwe border — have contaminated farmers’ crops and natural vegetation along the Limpopo River, a Northern Province inquiry heard this week.
The Agricultural Research Board told a commission of inquiry, appointed by provincial MEC of Agriculture Dr Tienie Burgers, that it had found traces of unregistered herbicides in and around the sisal fence.
“Their research has clearly shown that two products, Brumisal and Ethidimuron, are present not only in the sisal fence, but also in the seepage areas, the river bed and the agricultural crop areas,” said the commission’s Dr Gerhard Verdoorn. He also confirmed that the two herbicides were not registered as required by law.
The fence was erected in the early 1980s to keep “undesirable elements” from neighbouring countries from entering South Africa. Ironically, the area’s farmers whom the “impenetrable” sisal fence was supposed to protect, have for years claimed that they suffered great crop losses because of the use of herbicides on the
The fence was the responsibility of the former SADF and they employed contractors to maintain it from 1982 to around the end of 1992. For the first three years herbicides with the active ingredients of Ethidimuron and Brumisal were used.
Among the evidence is a letter dated July 6 1984, in which the manufacturer strongly advised the contractor against using these herbicides. The manager of the chemical section of the manufacturer warned in the letter that the continued use of the herbicide could be dangerous, “even to the sisal”.
The prescriptions on the label of the particular herbicide also specifically warn that it should not be used in the vicinity of water, agricultural crops and rivers — instructions which were clearly contravened. A list of plant species is mentioned which should not come into contact with the herbicide. Various of these are indigenous species in the area.
>From about 1986 a herbicide with the active ingredient Thebuthiron was allegedly used by the contractors. This herbicide is registered for use on the sisal, but it appears this, like the herbicides used earlier, was sprayed at a much greater frequency than the manufacturer recommended.
Ecologist Professor Ben van der Waal said: “If you use the substances every year at full strength, as it is alleged happened, for 10 consecutive years, then you’ll get an accumulation of the poison,” he said.
Irrigation farmers next to the fence have claimed that their crops declined dramatically since the application of the herbicides started in 1982. They complained that yield dropped up to 90 tons a hectare in the worst years. However, for many years these complaints were put down to the result of the bad drought in the area, increased salinity and even general bad farming practices.
But it is not only the border farmers who are concerned about the use of the herbicides. Ecologists are up in arms about the presence of herbicide poison in the sisal fence where it runs through the Matshakatini Nature Reserve, which has become all the more important in the context of talks about the establishment of a trans-national game reserve. The Matshakatini reserve would form an important link between the Kruger National Park and the parks of Mozambique, Zimbabwe and Botswana in the east and north.
Visiting the Limpopo area one can clearly see that the vegetation on the southern side of the river is in a poorer condition than on the northern side. This is not the case further east where the sisal fence is further removed from the river. But the Department of Agriculture claims infrared photos taken of the area show no difference — and say that even if there is a difference, it is not necessarily linked to the herbicides.
Van der Waal said the fence in itself had already damaged the environment in that it disturbed animal migration patterns. He said if the fence was removed it could leave a scar of more than 70km in the nature reserve which could take a long time to recover fully because of the presence of the poisons.
“It can take anything from 50 to a 100 years to recover. A long stretch in the middle of a national, possibly international, park where trees are still dying is totally unacceptable.”