Yorkshire Water is calling on farmers on land south of Barmby Moor to manage the use of slug control pesticides carefully.
The plea is part of new plans to reduce the impact the pesticides could have on tap water quality.
Slug pellets are commonly used by farmers this time of the year to control slug infestations, which risk eating away at crops and damaging food production.
It is estimated that around 22% of land used for wheat growing is affected by slugs.
However, the pellets occasionally leak into watercourses in Yorkshire’s farming heartlands around the outskirts of Pocklington.
An active ingredient in the pellets - metaldehyde - poses no danger to health or the environment, but its levels in the River Derwent, Wiske and Ouse have occasionally breached EU drinking water standards in the past year.
In response, Yorkshire Water and partners including the National Farmers Union are encouraging farmers to adopt an integrated pest management approach with less reliance on slug pellets.
Andrew Walker, catchment strategy manager at Yorkshire Water, said: “We really appreciate the efforts farmers in Yorkshire are making to reduce the amount of metaldehyde getting into our rivers. These measures include switching to ferric based pellets; adhering to the new 10 metre buffer strips and implementing the new integrated pest management plans, and other cultivation techniques which can control slug populations without the need for chemicals.”
NFU Vice President Guy Smith said: “Metaldehyde remains an important part of the management options available to farmers to control slugs and a crucial part of an integrated pest management plan. Using traps to assess slug pressures, ferric phosphate and cultivation are all useful alternatives to Metaldehyde as part of an integrated pest management plan.”