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A sunny Wednesday afternoon in June. Just outside Kagio, a small town in Kirinyaga, Joshua Murimi Wanjohi stands at the edge of his tomato field and watches as one of his farm workers stirs chemicals into a blue plastic barrel: “Topstar”, a fungicide from a Chinese manufacturer that he uses alternately with “Belt”, an insecticide manufactured by Bayer. Both contain toxic, highly hazardous ingredients whose approval has not been renewed in the European Union. The water turns yellow and starts to foam. The man fills the liquid into a portable pump that he straps to his back. He then walks through the bed and carefully sprays all the tomato plants. A cloud settles over the shamba, the bitter smell stings the nose. No mask, no gloves, no gumboots.

Some pesticides contain ingredients that might cause cancer or hormonal disruption, others influence the bee populations or the water quality in the surroundings. A river runs below Wanjohi’s field, which is also a source of drinking water for hundreds of people in the region. Is he aware that the poison could get into the drinking water? He shrugs his shoulders.

President William Ruto has declared agriculture a “leading sector of economic transformation”. He wants to massively expand the agricultural sector, supposedly to lift many people out of poverty. In order to increase yields, farmers are to rely more heavily than before on chemical fertilisers and pesticides, many of which have been developed in Europe, including by the German multinational corporations BASF and Bayer. Growing markets in countries like Kenya are becoming more and more important for German companies, as markets are saturated in other parts of the world. Pesticide imports have increased massively over the years; 500 tonnes of pesticides were imported in 2000, a figure that had risen to an estimated 18,000 tonnes by 2018.

Some of the products manufactured by these companies have long been banned in Europe because they are considered too dangerous for people’s health or have harmful effects on the environment. Kenya officially follows international standards when it comes to pesticides. But in practice, once registered, substances are rarely taken off the market, even if they are no longer allowed for sale in the country where they are produced. In 2023, the Pest Control and Products Board (PCPB) announced that eight highly hazardous pesticides would be phased out by the end of 2024 after a number of organisations petitioned parliament in 2019.

A Bayer brochure on pesticides used in tomato cultivation by Kenyan farmers does not mention any of the scientifically proven dangers they present. Individual products are even advertised as environmentally friendly even though they contain substances that have been proven to endanger water ecosystems. Wanjohi employs thirty men, each of whom he pays a daily wage of roughly KSh500. He also sells pesticides to other farmers in his two agrovet stores. While medicines can only be sold in pharmacies run by certified pharmacists, anyone can run an agrovet shop. Three years ago, Wanjohi took part in a Bayer Crop Science training course. Despite this, none of his workers wear protective equipment, gloves or masks. “Too expensive,” he says. Empty pesticide containers are strewn around the shamba.  

The German company Bayer, which in 2020 supplied 15 per cent of the pesticides sold on the Kenyan market, claims that their products are safe for use if the “proper application” rules are followed. They take years to develop those products in highly controlled laboratories in Germany and then test them under similarly controlled conditions in the field. The fundamental difference is that the market in Kenya is in no way like the market in Germany. Germany’s agriculture is industrialised. Kenya’s agriculture is mainly subsistence farming carried out in direct proximity to houses and water sources. Only vegetables grown for export are thoroughly tested for pesticide residues – products that are rejected because of high pesticide residues go back into the local market, as Daniel Wanjama of the Seedsavers Network explains.

After the last general election in Germany, the new government promised that in future exports of certain pesticides that are banned in Germany would be prohibited. It was an announcement that caused waves – but it no such decision has been implemented. Instead, a dispute has broken out between pesticide manufacturers and environmental activists, farmers and beekeepers over the planned regulation. This is about influencing politics and different vested interests, and it raises the question: Is the German government under obligation to protect people, animals and the environment in countries like Kenya from German products?

Kenyan researchers report that there is still very little knowledge about the effects of pesticides. However, a study shows that pollen and honey contain residues of pesticides that are harmful to bees. The active ingredient Imidacloprid – found in several products exported by Bayer and also manufactured by other companies – belongs to the neonicotinoids group and has been banned in the EU for years. According to a Route to Food report, Imidacloprid is the active ingredient in “Thunder”, one of Bayer’s bestselling products in Kenya.

Henry Muriuki of the Kenya Organic Agriculture Network in Kirinyaga says he knows farmers who have to pollinate their flowering pumpkins by hand – ”with cotton buds” – because there are no insects anymore. He has been trying to fight the uncontrolled use of pesticides for decades, as he witnessed how the introduction of pesticides coincided with the massive dying of bees. He wrote letters to universities, tried to meet with county politicians. Unsuccessfully. “All they have in mind is money, and I don’t have money. But the agrochemical companies have lots of money,” he says in frustration.

Around 6,000 kilometres away, in the small German town of Monheim am Rhein, a man stands in front of a glass box to show how responsibly he believes these substances are being developed. He says: “We protect everyone involved as best we can.” Fifty-one-year chemist Heiko Rieck is head of insecticide research at Bayer’s Crop Science Division. The department is surrounded by flowering fields enclosed by a high fence. “Alongside medicines, crop protection products are perhaps the most studied and analysed product group.”

A white robot arm moves up and down in front of a row of seedlings, spraying a clear liquid. The box is hermetically sealed, the side effects are still too uncertain. This is where substances are developed that are termed as highly hazardous pesticides. Each product is not only tested for its effectiveness, but also for possible side effects: What effect does it have on the plant? What consequences can its use have for humans, nature and animals? In order to answer these questions, the company carries out tests in greenhouses and laboratories as well as on test fields. Substances that are approved in Germany undergo a complex process that takes several years.

During the tour of his department, Rieck is at pains to show that Bayer’s products are safe for people and nature – as long as they are “used properly”, he says. This also applies to the active ingredient imidacloprid: if used correctly, there is no risk of harm to bees. But even in Germany, mistakes in its use are apparently being made; in 2008, residues of the imidacloprid insecticide on maize seed were apparently the cause of massive bee mortality in Baden. To this day, this active ingredient is widely used in Kenya and is one of the ingredients with a high market value.


For Bayer, the development of an active ingredient is like a huge bet: according to the company’s own figures, development costs more than EUR400 million. Rieck says,

“If an active ingredient would not be approved, our investment would be gone.”

That is why Bayer is spending a lot of money to exert public influence. In Germany, the company says it invests EUR2 million a year in a so-called liaison office to establish contact with politicians. At the European Union level, Bayer spends a total of more than EUR6 million a year on lobbying. The company has more than 100,000 employees worldwide.

These companies are also doing everything they can to keep their products on the Kenyan market. CropLife Kenya, the national branch of CropLife International, the world’s largest lobbying association for pesticide manufacturers – on whose board Bayer and BASF sit – negotiates directly with the authorities. Just how influential CropLife Kenya is is demonstrated, for example, by the fact that around half of the profits from import duties on pesticides flow directly back to the lobby association itself. The other half of the import fee goes to the Pesticide Control and Products Board (PCBC), which is chronically underfunded. Former head Esther Kimani says: “The only tests we do in Kenya are to check whether the product is effective against the infestation of the plants.” There are still hardly any studies on the long-term consequences. When asked, a representative of the authority explains that they rely on the research the companies themselves submit. Meanwhile, companies like Bayer are providing scholarships for PhD students.

Different actors report that when it comes to involving civil society or smaller farmers’ organisations, the PCPB is more reluctant. It also emerged during the interview with the PCPB that the agrochemical companies finance travel and training for the authority.

Bayer repeatedly emphasises how much they care for farm workers and the environment. Following its takeover of Monsanto in 2016 amid public criticism of the merger, Bayer launched a charm offensive. “We have listened. And understood,” it said in an advertisement, and continued: “There must be no doubt that we need further progress for sustainable agriculture as the basis for our food supply.” Images like that of farmer Wanjohi, who lets his employees spray without protective equipment, are not good for the company. This is one of the reasons why four so-called Bayer Centres of Excellence have been operating in Kenya since 2022, where farmers can learn how to handle the toxic substances correctly, free of charge.

The company knows very well that few if any of its customers in Kenya adhere to the recommended safety measures. Not when it comes to protective equipment while using the products, nor when it comes to respecting the physical distance to housing, or the waiting period between spraying and harvesting. “They spray today and harvest tomorrow,” says Erastus Mwangi, the agronomist at the Bayer Centre of Excellence. The company wants to teach farmers the importance of adhering to the safety precautions but, as David Ndungu, the head of sales at Bayer East Africa, says, the central question for Bayer is: “By how much can we increase our business by having a Centre of Excellence in Central Kenya?” Providing extension is a marketing strategy for the agrochemical companies. The public extension system under the Minstry of Agriculture is chronically underfunded.

The big players in the agrochemical industry have a good relationship with the authorities. “There is a lot of cooperation,” says Ndungu. “Whenever we have field days, we are inviting the county government’s representative in agriculture, we like them to be part of this transformation training.” Daniel Wanjama has worked with the ministry of agriculture for ten years. He is still irritated as he recounts the many occasions on which representatives from big agrochemical companies used to present their newest products to a room full of ministry employees. “Even the very senior ministry officials would attend these functions and say, ‘we will support you in this,’” Wanjama says. “That made everyone believe that the solution to any situation in the field is basically the chemicals that the companies are producing.” Potential dangers were not part of those conversations.

When the German Minister of Agriculture Cem Özdemir declared in September 2022 that efforts would now be made to ban the export of harmful pesticides, Bayer and BASF got into position. Internal documents from one of the regional ministries of agriculture in Germany show that both Bayer and BASF reached out to the minister by email about the proposed ban and were granted follow-up meetings. As early as November 2022, a BASF representative wrote to the ministry: “In the medium term, a national export ban on certain PPPs [plant protection products] would lead to an exodus of domestic production facilities with high standards and jobs.” In the following weeks, BASF provided a legal opinion to prove how problematic the planned export ban is and again threatened to relocate the production of pesticides.

It seems that their lobbying efforts have been successful. A bill that was supposed to be implemented a year ago has since stalled. And the initial ideas have been largely watered down: hardly anything remains of the original demands for a comprehensive ban on the export of active ingredients not approved in Germany. Now only the export of already mixed products that have been explicitly banned because they are harmful to human health is being proposed in the bill that is awaiting approval. Products whose approval has expired, often because new research showed that they are no longer fit for use, and ingredients such as imidacloprid, which are harmful to the environment and dangerous to bees, will continue to be exported, even when the bill is passed.

In Germany as well as in Kenya, there is a growing movement for change in the civil society. Daniel Wanjama is part of this movement. As the coordinator of the Seed Savers Network, he and his team offer training for successful agriculture that does not rely on harmful pesticides. Wanjama tells stories of farmers who seek his support after suffering pesticide poisonings, or because the water from the rivers in their area is no longer potable because of the uncontrolled use of pesticides. According to Wanjama, a central problem is that “modern agriculture” is presented as a means of making money and no longer from the angle of producing good food. “You’re being told to make money on one acre of land, which is very small. So maybe it will not give you money. It will only give you problems if you upset the system with fertilisers and pesticides,” Wanjama says.


If the development of crop protection products is a bet, then Bayer seems to be winning it. In 2022 alone, Bayer Crop Science generated sales of more than US$25 billion – more. On the slopes of Mount Kenya, Henry Muriuki of the Kenya Organic Agriculture Network has taken care of his bees and his garden where he grows avocado trees, cabbages and zucchinis, with wild flowers blooming in between. To protect his plants from pests, he makes his own pesticide from the urine of his rabbits, goats and cows. It is not intended to kill the insects, but only to repel them. Scientific studies suggest that such products can be successful. In Kenya, the international insect research centre ICIPE is also conducting research into low-threshold, environmentally friendly biopesticides. Three products based on their research have been introduced into the market, but are not known to most farmers. There is not enough money for their commercial production and marketing. Down in the plains at the foot of Mount Kenya, many farmers prefer to use the Bayer product “Thunder” instead, a product that has been banned in Europe for years. The balance of power in the dispute over the future of agriculture in Kenya is unevenly distributed.

This research has been supported by Journalismfund EU.