Mwea Farmers Warned Against Unapproved Chemicals for Snail Control

In Summary

• KEPHIS warns Mwea rice farmers against using unapproved chemicals to combat apple snails.
• Invasive snails damage 50–80% of rice seedlings across 1,500 acres in Mwea.
• Unapproved pesticides risk consumer health, environmental harm, and export bans.
• Farmers urged to use biopesticides, ducks, and drainage to manage snail infestations.
• Government supports research for eco-friendly solutions and irrigation expansion.
• Challenges include high control costs (KSh 20,000/ha) and duty-free import threats.

The Kenya Plant Health Inspectorate Service (KEPHIS) has issued a stern warning to rice farmers in the Mwea Irrigation Scheme, Kirinyaga County, against using unapproved and potentially harmful chemicals to control the invasive golden apple snail (Pomacea canaliculata), which threatens rice production. The alert, announced on August 4, 2025, follows reports of farmers resorting to unregistered pesticides to curb the pest, which has damaged 50–80% of rice seedlings across 1,500 acres in Ndekia, Tebere, and Kimbimbi sections since its introduction in 2020.

KEPHIS Managing Director Prof. Theophilus Mutui emphasized the risks of unapproved chemicals, including consumer health hazards, environmental contamination, and potential export bans to markets like the EU. “Using unregulated pesticides can lead to toxic residues in rice, endangering lives and harming ecosystems,” Mutui said at a farmer training session in Mwea. A 2023 Route to Food Initiative report noted that 76% of Kenya’s pesticides are highly hazardous, with chemicals like chlorpyrifos linked to cancer and water pollution, underscoring the need for caution.

The golden apple snail, known for its muddy brown shells and pink egg masses, destroys rice by feeding on young shoots and can lay up to 3,000 eggs, surviving in mud for six months. Farmers like Monica Wambui are spending KSh 20,000 per hectare on labor-intensive methods like handpicking snails and eggs, which offer only partial relief. “Chemicals seem faster, but we’re told they’re risky. We need affordable, safe solutions,” she said.

Instead, KEPHIS and the Mwea Research Centre recommend eco-friendly methods such as draining fields for the first 30 days after planting, using ducks to eat young snails, and installing barriers in water canals. Trials with biopesticides are underway, as chemical controls have harmed aquatic life in past pilots, according to Kirinyaga Governor Anne Waiguru. “We’re investing in research for sustainable snail management,” she said, noting collaboration with the National Irrigation Authority.

The government is expanding Mwea’s irrigation to boost production to 846,000 tonnes by 2032, while KEPHIS enforces quarantine protocols to prevent snail spread to Ahero and Bura. Farmers are urged to adopt climate-smart practices like transplanting older seedlings, but high costs and water shortages remain challenges. Further training and research outcomes are expected by early 2026 to safeguard Mwea’s rice industry, which produces 70% of Kenya’s 264,000-tonne annual output.