Maize is South Africa's staple food and some people eat it up to three times a day. According to the South African Department of Science and Technology, 86 percent of maize and 85 percent of soy in South Africa are genetically modified and most are sprayed with the weedkiller Roundup which contains glyphosate.

According to the International Agency for Research on Cancer (IARC), a subdivision of the World Health Organization (WHO), there is strong evidence that glyphosate can cause cancer. Institutes in countries where glyphosate is in high use, for example Argentina and Canada, have carried out studies assessing that the use of the weedkiller leads to kidney diseases, birth defects or childhood cancer.

In the beginning, glyphosate was only used before seeding to get rid of weeds but biotechnology opened up new possibilities through the use of genetic modification. Now plants can be engineered to be resistant to poisons like glyphosate so that the weedkiller can be sprayed directly on to the crops.

Farmers spray glyphosate on their fields to kill weeds and pests

Many countries, including Germany, are highly critical of the use of glyphosate. In June 2016, the European Commission reduced its licensing of the product from 15 to 1.5 years following protests from member states. Other institutions, including the US Environmental Protection Agency and the European Food Safety Authority, object to the IARC's findings.

Poison or promise?

"Why is South Africa poisoning its people?"This is how Chief Mangosuthu Buthelezi, the President and founder of South Africa's Inkatha Freedom Party and traditional prime minister of the Zulu nation, titled a recent press release.

"It is disturbing that the government has abandoned its responsibility for the well-being of South Africans," the press release read.

Toren Wing is one of the co-signers of the press release and chairperson of the South African Traditional Doctor's Union. Even though no official statistics on cancer have been published since 2011, Toren Wing stated in an interview with DW that the rate of cancer is rising in South Africa.

"I work with about 500 doctors and the word from the doctors on the ground is that cancer is exploding in the country," he said. "Cancer used to be one in a thousand. Then some twenty or thirty years ago the figure was one in twenty-seven. Now the number is one in three."

Corporations versus farmers

"Our concern is the lack of any kind of research into the possible effects of glyphosate on humans," said Haidee Swanby, a researcher at the African Center for Biodiversity (ACB), in an interview with DW. Her institution campaigns against the activities of Monsanto, the main producer and provider of glyphosate in South Africa.

"The issue in Africa around those chemicals is that people don't wear safety gear, they often don't understand the language that the instructions come in. I've seen people mixing with their hands in open drums, I've seen people storing herbicides in their kitchen and people using empty containers to go and fetch water from the river," said Swanby.

The main ingredient of Monsanto's "Roundup" is glyphosate

The managing director of Monsanto in South Africa, Kobus Steenekamp, denies any negative effects on human health.

"We still believe that it's a safe product to use and we are guided by many internal studies. Glyphosate is still guaranteed and there is a full review of safety in the use. We still challenge the classification of the IARC," he said. "So many things are put in place like protective clothing, for instance."

Environmental impact

Glyphosate is the most-used weedkiller in the world. In 2006 South Africa's farmers sprayed 2 million liters per year, according to the African Center for Biodiversity. Now, the amount is more than five times higher.

While there continues to be a debate on the pesticide's effect on humans, the effect on the environment is clear. For example, weeds which were meant to be killed off by the pesticide have become resistant. The emergence of these so-called superweeds means that new chemicals have to be introduced into the cycle.

Swanby sees this as good business for big enterprises like Monsanto: more superweeds, more pesticides. But she questions the role of her country in this industrial domination of the agricultural section.

"South Africa has played a big role in helping to promote the use of GMOs in other countries. So definitely South Africa is a wonderful place for Monsanto. We are a very industrialized, agricultural country and we are very powerful on the rest of the continent. It's a perfect springboard," she said.

A success story?

Monsanto's Steenekamp sees a success story in genetically modified crops and glyphosate in South Africa. According to him, the productivity is higher on a smaller surface. Whereas in the 1970s two tons of crops were produced per hectare, Steenkamp claims that today the amount has more than doubled. He sees his company as the solution to food scarcity and even as a protector of biodiversity.

"Traditionally when you spray an insecticide over a maize field, you would have killed all the non-target or beneficial insects as well," he said. "Now you also protect all the other biodiversity."

Some 14 percent of land in South Africa is used for crop production

The African Center for Biodiversity has joined the UK's Pesticide Action Network, Canada's Biotechnology Action Network and the international Friends of the Earth organization to oppose the use of glyphosate. According to them, glyphosate causes serious decreases in biodiversity by eradicating wild plants which are an important food source for many insects and birds and is highly toxic to aquatic life.

Mariam Mayet, director of the ACB, wrote in a press release that "South Africa is at a crossroads: either it must abandon Monsanto’s GM maize or face an economic, social and ecological crisis."