Observe a 5m buffer zone when spraying residual herbicides in oilseed rape this autumn, Patrick Goldsworthy, Voluntary Initiative manager, is reminding growers.

“This summer we encouraged farmers to establish permanent 6m grass buffer strips between oilseed rape crops and watercourses to reduce the risk of pesticide losses in surface run-off.

“While such strips exist on many farms, we recognise very dry conditions this autumn have not been ideal to establish grass margins. But whether the strips were established, it remains good practice when spraying herbicides to observe a 5m no-spray zone in oilseed rape adjacent to any watercourses, even small ditches.”

Key oilseed rape herbicides have been found in raw water at levels above the EU drinking water standard. “It is a hard balancing act. Optimum performance comes when soil is moist and cooling but increases run-off risk.”