Kenya’s agricultural sector faces a critical challenge: only 10% of the country’s total land is arable, according to a 2017 government survey. This puts immense pressure on farmers to maximize yields from every available hectare, in a country where 30% of the GDP is contributed by agriculture. Still, pests and diseases threaten crop production at alarming levels, with losses ranging from 20% due to fungal diseases to as high as 90% from invasive species and scale insects.
In response, Kenya’s annual pesticide imports have been doubling since 2015. However, food security has not seen a commensurate improvement. The initial benefits of synthetic pesticides often give way to long-term risks: pest resistance, soil degradation, and potential nutritional decline in crops. What’s worse, an estimated 44% of the pesticides used in Kenya contain active ingredients already banned in the European Union due to health and environmental concerns, according to a damning report released in 2023.
Recognizing these risks, the Pest Control Products Board (PCPB) has launched a review of six widely used pesticides—remnants of the 1970’s Green Revolution era, marked by widespread adoption of synthetic pesticides and fertilizers to increase agricultural output.
The Chemicals Under Review—and Why
Acrinathrin
Usage: A synthetic pyrethroid insecticide used on potatoes, tomatoes, and beans for mite and aphid control. Concerns: Pyrethroids disrupt aquatic ecosystems and have been linked to neurological disorders in children, according to a 2018 study in the International Journal of Environmental Research and Public Health. Biological Alternatives: Natural predators (Phytotech, Montech, Amblytech),Entomopathogenic fungi, (Lecatech, Beauvitech).
Hexaconazole
Usage: A systemic fungicide for powdery mildew and rust in wheat, barley, and vegetables. Concerns: Flagged by the FAO in 2021 as a persistent organic pollutant with bioaccumulation risks. Biological Alternative: Beneficial bacteria (D-Press).
Propoxur
Usage: A carbamate insecticide for household pests such as mosquitoes and cockroaches, and agricultural use in coffee and vegetable farms. Concerns: WHO classifies it as moderately hazardous, with studies linking exposure to Parkinson’s disease and cognitive decline.
Diazinon
Usage: An organophosphate insecticide used in horticultural hotspots in Naivasha and Mount Kenya to control aphids, beetles, and caterpillars. Concerns: A 2019 KEPHIS report found that 40% of tested vegetables exceeded safe levels of organophosphate residues. In fact, the EU banned Diazinon in 2007 due to its neurotoxic effects. Biological Alternatives: Fungal biopesticides (Beauvitech), granuloviruses (Cryptogran), Entomopathogenic nematodes (Nematech H) and Plant extracts like Nemguard SC.
Methomyl
Usage: A carbamate insecticide for aphids, caterpillars, and flies in horticultural zones. Concerns: Highly toxic to bees and other pollinators, with increased cancer risks for farmworkers, according to a 2021 EPA study. Biological Alternatives: Entomopathogenic fungi (Beauvitech), soil-drenched nematodes (Nematech S).
Profenofos
Usage: An organophosphate insecticide used in cotton and vegetable crops in Makueni, Machakos, and coastal regions. Concerns: Linked to respiratory disorders, endocrine disruption, and water contamination—30% of samples in farming zones contained unsafe levels, per a 2022 NEMA report. Biological Alternatives: Predatory mites (Amblytech), beneficial nematodes (Nematech S, Nematech H), fungi (Beauvitech).
The Case for Biopesticides
Kenya is steadily transitioning to Integrated Pest Management (IPM), with biopesticides charging at the forefront. Adoption is particularly notable in export-driven farms in Naivasha, Thika, and Kericho, where meeting international standards is non-negotiable.
Biological control methods have proven successful before even outside the farm. In the 1990s, Lake Victoria faced a water hyacinth invasion that threatened fisheries and water transport. Scientists introduced two species of weevils—Neochetina bruchi and Neochetina eichhorniae—which slashed the hyacinth cover by 90%.
Unlike synthetic pesticides, biopesticides offer precise targeting, sparing beneficial insects like bees and ladybugs that are crucial for pollination and ecosystem health. They also decompose naturally, reducing soil and water contamination risks while mitigating pesticide resistance.
With the mounting evidence against harmful chemicals and the success of sustainable alternatives, Kenya stands at a crossroads. The future of its agriculture depends not just on higher yields, but on safer, long-term solutions that protect both farmers and ecosystems.