Farmers Use Technology to Develop Slug Prediction Tool, Reduce Pesticide Use

The New Weapon Against Crop-Destroying Slugs

Farmers in England believe they have a new weapon in their age-old battle against the slugs that destroy their crops: modern technology. Slug prediction maps, created by computer models as part of a research project, are now helping growers to better target the use of pesticides, saving them money and reducing environmental harm.

Technology Breakthrough: The Slimers Project

The monitoring work is being carried out as part of the Slimers project – which stands for Strategies Leading to Improved Management and Enhanced Resilience to Slugs. This three-year, £2.6m scheme began in 2023 and is funded by the Department for Environment, Food and Rural Affairs, led by the British On-Farm Innovation Network.

A team of 28 "slug sleuth" farmers were recruited to work alongside scientists to increase understanding of the invertebrates' behavior by setting up traps – large plastic saucers – on their land. This information was fed into a computer model, and an algorithm was used to predict where the slugs would be found in arable fields, while soil samples were also taken.

Financial Impact: Saving £44m Annually

Slug damage is not just frustrating but also expensive for arable farmers, with damage to wheat and oilseed rape crops estimated to cost almost £44m a year in the UK. The gastropod mollusc grazes on the young leaves of emerging cereal crops and has also been known to eat barley, oat and wheat seeds. Slugs also damage potatoes and can have a huge impact on vegetable crops, as whole fields sometimes have to be abandoned if there are signs of an infestation.

The resulting slug prediction maps were tested by 16 farmers over the past autumn and winter, and have already helped them to halve the amount of slug pellets they need to use to control the pests.

Industry Transformation: Precision Agriculture Takes Root

Charles Paynter, a farmer in Bedfordshire who was involved with Slimers from the start, has already cut back on his use of pesticides. "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.

The chemical metaldehyde, which was commonly used in slug control products in the UK, was banned in 2022, and this has resulted in the increased use of ferric phosphate pellets. There is, however, appetite for alternatives to pesticides.

Prof Keith Walters and a team from Harper Adams University created the slug prediction model. "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."

Future Outlook: Resistant Crops and Wider Applications

Another part of the Slimers project has been working to develop slug-resistant wheat varieties. Scientists have identified three areas of the wheat genome that are responsible for resistance to the grey field slug, and it is hoped this finding will pave the way for plant breeders to develop new varieties that will not be damaged by what farmers call one of the most persistent pests.

As precision agriculture continues to evolve, the techniques developed through the Slimers project could potentially be applied to other crop pests and agricultural challenges, offering a template for how technology can help address agricultural problems while reducing environmental impact.