Just because relatively few autumn herbicides reached watercourses last season, don’t think the risks have gone away.

Vigilance is vital to ensure growers continue to have as wide a range of products as possible.

That’s the message from industry specialists including Voluntary Initiative manager Patrick Goldsworthy, who warns that complacency could lead to more restrictions and the loss of products.

“Generally, last autumn was quite dry and we had perfect spraying conditions. So in most situations the risks of pesticides getting into water were lower than usual. Indeed in some places drains never ran,” says Mr Goldsworthy.

Key ESF river basins
Anglia region * R Wensum * R Yare and Waveney Severn region * R Teme * R Lugg Humber region * R Yorks Ouse, Nidd & Swale

The exceptions were mainly where heavy rain caused surface run-off.

In terms of what sprayer operators should do to avoid polluting watercourses little has changed in two years. But more must appreciate that it is not solely isoproturon (IPU) that requires attention.

“We must also be vigilant with chlorotoluron (CTU), simazine, and mecoprop.” There are decision trees to help with them, all available from the VI website*.

“And if we have another wet autumn like 2004, there’s always a risk that some oilseed rape herbicides – for example carbetamide and propyzamide – may get into water,” says Mr Goldsworthy.

To tackle parts of the country where the risks of contamination tends to be greater, VI staff have been asked to provide action plans for five key river basins (see panel) under the government’s England Catchment Sensitive Farming Delivery initiative.

“We effectively already have a toolbox of protective measures that CFS officers can use straight away.”

Based on ideas from the VI’s own pilot catchments exercise, it involves encouraging greater use of decision trees*, more effort to increase awareness of water pollution issues, and regular text message alerts to guide growers on the suitability of spraying conditions.

Be sure to get good advice on resistance and which products to apply and don’t forget the damage that careless farmyard practice can do, urges Mr Goldsworthy. “If you have a spill don’t flush it down the drain, as it will end up in water.

“Soil management is perhaps a bigger issue than we thought.” Spraying should always be avoided if soil has wide cracks. That is because herbicides can easily be washed through to field drains by heavy rain, he says.

At the other extreme treating wet land, even if it is possible to travel, should be shunned to avoid spray chemical run-off.
Cross-compliance buffer strips undoubtedly help, he notes.

Once in the field, operators should strive for perfection even if it is not always practically possible, he says.

“It’s all about accurate application. Spray the headlands last so that you don’t carry herbicide off the field in mud on the sprayer and tractor wheels.”

• www.voluntaryinitiative.org.uk