Details of aminopyralid approvals

The approval of the Dow AgroSciences herbicide, aminopyralid, has been re-instated by ministers on the recommendation of the Advisory Committee on Pesticides.

The move lifts a voluntary suspension of approval for sales and use which the company sought in July 2008 after sensitive crops on some allotments and gardens were affected by manure containing traces of the herbicide.

Aminopyralid is a highly effective weedkiller for professional users. It is valued by farmers seeking to control pernicious and poisonous weeds such as ragwort, thistles and docks in pasture. In specific formulations it also has the potential to control invasive weeds, such as Japanese knotweed, in amenity areas and industrial sites.

Since sales and use were suspended, farmers have campaigned for the product's return because of the high levels of long-lasting weed control aminopyralid-based products offer. Those who have used the product since its launch in 2006 saw improved pasture and enjoyed increased output from their fields, compared with that offered by other products on sale to control weeds in grassland.

Dow AgroSciences, however, has always insisted that it would not seek to re-introduce aminopyralid before ways were found that minimised the risk of any repeat of the unfortunate incidents of 2008 and 2009.

The active ingredient will be re-introduced with new recommendations and a stringent stewardship programme devised to prevent both the inadvertent movement of manure from farms and its safe disposal on farm to avoid damage to sensitive crops and habitats such as flower-rich meadows. Key to this is the requirement that products containing aminopyralid are only applied to agricultural grassland that will be grazed by cattle or sheep; not land where forage will be cut for hay or silage. This requirement aims to ensure manure generated from treated grassland remains on the pasture. Problems have arisen when conserved forage from treated pasture was fed to housed livestock and manure created in large quantities.

Supporting these new recommendations is an enhanced stewardship package which will require anyone supplying or advising on the use of aminopyralid to be re-trained in the details of product use. Those applying, or using, products containing aminopyralid are required to confirm in writing that they have been instructed on product use, manure management issues and measures to reduce the risk of damage to flower-rich grassland, particularly those under agri-environment schemes or designated as Sites of Special Scientific Interest (SSSI). These records form part of a user traceability system.

The new stewardship requirements are stringent. We believe they will mitigate against manure leaving farms where aminopyralid has been used and so help to safeguard against repeats of sensitive crops being affected. In addition, they will reduce the risk posed to existing flower-rich grasslands and land being managed to increase its wildflower interest by giving clear guidance on the disposal of contaminated manure on farm, and management of grazing animals feeding on treated pasture.

The changes to how aminopyralid products will be used and the associated stewardship plan should allay concerns amongst gardeners and allotment-holders over using manure. However, it remains good practice to know the provenance of any manure as other materials can contaminate it.

Speaking for farmers, NFU Deputy President Meurig Raymond said: "We are pleased to see the suspension on the use of aminopyralid lifted. Many grassland farmers have found this a particularly valuable product in improving grassland and controlling pernicious weeds, such as ragwort and thistle.

"However, it is clear that those recommending and using the products have a duty to follow the stringent new label instructions. Not only is it a legal obligation, but important for the reputation of the industry."