14 June 1996

Germanys IPU clampdown is worrying for UK

By Andrew Blake

SWINGEING new restrictions on the use of isoproturon in Germany, the member state currently re-assessing the herbicide under the EUs review programme, could have serious implications for the UK.

"IPU is certainly not off the hook," Dr Steve Moss of IACR-Rothamsted told an ARIA meeting at IACR-Long Ashton last week.

Dr Moss pointed out that about 2300t of IPU is used annually in the UK. It was sobering to realise that just 200g – only a coffee cup full – was enough to take a days water supply for London over the 0.1ppb limit.

Although this would pose no health hazard, as the rules stood, growers had to use the chemical with care, he warned. "It really is up to the farming community to take it seriously."

Dr Moss believes the new German constraints, breaches of which attract fines of £40,000, are clear pointers to the outcome of the EU review. They prevent IPU being applied on "drained areas" from Nov 1 to Mar 15, though the definition of drained remains unclear.

Contrary to MAFFs position, the German view is that the chemical has strong environmental effects, he added. To minimise the risk of run-off the authorities there require cover cropped strips at least 10m (33ft) wide to be placed around fields with slopes of more than 2% if they are due to receive IPU.

"It is all slightly depressing, but we will have to wait and see. The Water Authorities and the Environment Agency here are flexing their muscles. But it is very hard to get any clear idea of how fast anything will happen in the UK."

Trials indicated that loss of IPU from the herbicide armoury would have grave consequences for UK growers, especially those faced with resistant blackgrass, explained Dr Moss.

Be ultra-careful when washing gloves if you have been spraying isoproturon herbicide. That warning to sprayer operators comes from AgrEvos Dr Roy Hewson as pressure to keep the chemical out of water supplies continues.

He believes few farmers are fully aware of the tiny amounts needed to tip concentrations over the critical 0.1ppb imposed for drinking water.

One study suggests there is enough IPU on a pair of gloves at the end of a days spraying to contaminate a 100m (330ft) farm ditch 1m (3.3ft) wide by 1m (3.3ft) deep. In Germany disposable gloves are now recommended and washing the outside of sprayers must be done in the field, he notes.

Small spills and direct over-spraying of streams, albeit momentarily, can have a dramatic impact, adds Dr Hewson.

His emphasis on so-called point sources is spurred by findings from 1995 concentrations in watercourses. "Last autumn there were some quite high peaks, which related to rainfall events and hence the increased flow. The really interesting point is that field drains didnt start running until just before Christmas, so these peaks must therefore have come from spillages and washings."

&#8226 Strong environmental effects.

&#8226 No IPU allowed on "drained" land Nov 1 to Mar 15.

&#8226 10m (33ft) of cover to serve as buffer strip where ground slopes more than 2%.

&#8226 Fines of £40,000 for contravention.

Use IPU with care to protect its future, says AgrEvos Roy Hewson.