Metazachlor and Quinmerac Stewardship
Protection of Water, Best Practice Advice
Why Metazachlor matters
Oilseed rape is an important break crop in the arable rotation. It is especially important on heavy land where spring crop establishment can be difficult.
Metazachlor and quinmerac form the foundation of most winter oilseed rape weed control programmes and are key active ingredients for the crop, but in common with some other major herbicides, they have been detected in watercourses at levels that risk non-compliance with the Water Framework Directive (WFD), the EU legislation drawn up to protect all surface and ground waters.
The water companies report that if they cannot show progress in reducing pesticide concentrations in raw water abstracted for drinking water supply, there will be further restrictions on their use. DEFRA has to-date looked at voluntary measures to deliver WFD compliance. It considers a regulatory approach to be a last resort, understanding growers’ needs and the agronomic challenges they face.
Joint initiative from BASF and Adama
BASF and Adama have joined forces on a European basis to develop stewardship guidelines specifically for metazachlor and quinmerac to try and mitigate against this threat and build on the general best practice advice within the Voluntary Initiative (VI). Both companies are also involved in the 'OSR Herbicides? Think Water' stewardship campaign.
How can Metazachlor and Quinmerac reach water?
The major route by which metazachlor and quinmerac are entering water is via field sources such as surface run-off or via field drainage. Spillages are also an issue, but more easily avoided. Field sources represent a far greater challenge, with prevention reliant upon sound agronomics.
In line with all metazachlor and quinmerac label approvals for 2015, all applications should be limited to a maximum of 750g metazachlor and 250g quinmerac per hectare.
Drained fields, including temporary – aim for 1st October, cut off 15th October
Applications after 1st October can be made as long as soil and seedbed conditions are good and drains are not flowing
Drained fields in Surface Water Drinking Water Safeguard Zones cut off 1st October (visit WIYBY for zone details).
Is your land at risk?
The majority of heavy, drained soils are likely to be at risk of metazachlor and quinmerac reaching surface water. To date, many central areas of England have been officially identified by the Environment Agency as Surface Water Drinking Water Safeguard Zones for metazachlor and/or quinmerac.
To find out if your land, or if the land your advise upon, falls is in an ‘at risk’ catchment, enter your postcode at the Environment Agency’s ‘ WIYBY’ website. The interactive map will reveal if the area is within a Safeguard Zone and if metazachlor and/or quinmerac are mentioned, then the most stringent stewardship application timing advice is relevant to you.