Farmers in England are harnessing modern technology to combat slug damage, which costs the UK an estimated £44 million annually in wheat and oilseed rape losses. Through the Defra-funded Slimers project, slug prediction maps have enabled growers to halve their use of slug pellets, saving money and reducing environmental impact.
How the Prediction Tool Works
The Slimers project—short for Strategies Leading to Improved Management and Enhanced Resilience to Slugs—recruited 28 “slug sleuth” farmers to work alongside scientists. These farmers set up large plastic saucer traps on their land to monitor slug populations. The data collected was fed into a computer model, which used an algorithm to predict where slugs would be found in arable fields. Soil samples were also taken to refine the predictions.
The resulting maps were tested by 16 farmers over the past autumn and winter, leading to a 50% reduction in the amount of slug pellets needed to control the pests.
Farmer Success Stories
Charles Paynter, a farmer in Bedfordshire involved with Slimers from the start, has already cut back on pesticide use. “My threshold for taking control measures is higher now because I have been able to prove to myself that I can evaluate the risks from slug activity with greater accuracy,” he said.
Scientific Validation
Prof Keith Walters and his team from Harper Adams University created the slug prediction model. They are now confident it works. “We already knew that slugs didn’t occur randomly across fields, but that they form distinct patches according to soil type and climatic conditions,” Walters said. “The slug sleuths’ data of slug populations across their fields helped us develop that understanding further and allowed us to confirm our hypothesis about how slug patches re-form after waterlogging.”
He added: “In waterlogged soils, patches become unstable and break down, but we have now confirmed that patches re-form temporarily in places we wouldn’t expect in normal conditions and then quickly return to their predicted areas once more typical soil conditions return.”
Broader Impact on Pesticide Use
The chemical metaldehyde, commonly used in slug control products in the UK, was banned in 2022, leading to increased use of ferric phosphate pellets. However, there is growing appetite for alternatives to pesticides. The Slimers project also works on developing slug-resistant wheat varieties. Scientists have identified three areas of the wheat genome responsible for resistance to the grey field slug, which could pave the way for new varieties that are less vulnerable to what farmers call one of the most persistent pests.
Project Details and Future Outlook
The three-year, £2.6 million scheme began in 2023 and concludes in late August. It is funded by the Department for Environment, Food and Rural Affairs and led by the British On-Farm Innovation Network. The success of the prediction maps offers a promising tool for arable farmers to target pesticides more precisely, saving money and reducing environmental harm.
