23 August 2001
Old v new in weed-control wars

By Tom Allen-Stevens

SPRAY manufacturer Aventis has hit back at competitors claims that new herbicide chemistry may take a significant chunk of the market from isoproturon.

IPU is a cost effective choice and still looks set to play a strategic role in the control of grass weeds on many farms this autumn, says the company.

The active ingredient forms the backbone of Aventis autumn weed control line up, partnered with diflufenican in products such as Panther and Javelin.

But its dominance of the market now appears threatened as a raft of new active ingredients join the armoury this autumn.

Herbicide resistance problems and concerns over the levels of IPU found in groundwater have also put a question mark over its future.

“The good news for growers is that there are no anticipated changes in legislation that will effect usage this autumn,” says Aventis Gordon Anderson-Taylor.

Maximum annual dose remains at 2500g/ha with no buffer zone requirements, but growers are advised not to exceed 1500g/ha if applied after 31 October.

These voluntary stewardship guidelines were introduced last year after detection of traces of IPU in surface water and subsequent water company pressure.

Dr Anderson-Taylor concedes that in some scenarios IPU is not the front line black-grass control product it once was.

“But IPU still provides effective control of a range of grass weeds and has a strategic role to play in the control of grass weeds and some broad-leaved weeds.

“IPU is well understood by farmers and agronomists, has a wide range of tank mix partners, and has to be one of the most cost-effective cereal herbicides available.”

He adds that low profits may see growers turning to lower-priced products this autumn and few would wish to be caught out by wet autumn conditions again.

“A shift back to earlier applications of residuals is a distinct possibility for growers now reluctant to risk later applied contact products,” he said.

IPU is still an important tool in the box and is capable of containing black-grass on some farms and can also contribute to sterile brome control, he added.

His comments followed the launch of BASFs new herbicide PicoPro (pendimethalin + picolinafen) on Wednesday (22 August).