Metaldehyde Stewardship Best Practice for 2010
• Use minimum active per hectare to avoid drainage and run-off losses
• No pellets to be applied within six metres of a watercourse and ditch
• Maximum single application:  210 g metaldehyde a.s./ha.* For additional protection of water, suppliers / BASIS advisors may recommend rates reduced to 160 g a.s./ha or less.
• Maximum total dose rate from 1st August to 31st December: 210 g metaldehyde a.s./ha*. For additional protection of water, suppliers / BASIS advisors may recommend rates reduced to 160 g a.s./ha or less.
• Maximum total dose rate: 700 g metaldehyde a.s./ha/calendar year*
• Do not apply when heavy rain is forecast
• If drains are flowing do not apply metaldehyde based slug pellets

 *from any combination of metaldehyde products

New guidelines for the 2010 slug pelleting season significantly reduce the advised levels of metaldehyde that can be applied during the key autumn months.

Announcing the changes at a meeting held at Severn Trent’s Cropston visitor centre, the Metaldehyde Stewardship Group (MSG) revealed that the amendments to best practice are a result of a water catchment study. It showed diffuse losses through the soil profile and into drains during the autumn as having as having a far higher impact on the levels of metaldehyde being detected in watercourses than first thought.

The new best practice guidelines maintain the annual maximum advised dose rate for the calendar year at 700g. However, a new maximum single application rate of 210g metaldehyde per hectare has also been set, down from 250g. Additionally, the total recommended dose rate of metaldehyde applied from 1 August and 31 December is cut to 210g metaldehyde per hectare. For additional protection of water, suppliers / BASIS advisors may recommend rates reduced to 160 g a.s./ha or less.There was previously no restriction during this timeframe other than a maximum advised dose rate for the calendar year.

In all cases the best practice guidelines note that suppliers or BASIS advisers may recommend individual dose rates reduced to 160g of metaldehyde per hectare or less.

The MSG’s chairman Dr David Cameron said that the new guidelines build on last year’s successful ‘Get Pelletwise’ campaign following which there was an over-all drop in the levels of metaldehyde exceedances being detected by water companies at raw water abstraction points.

“But, the threat to the future of this important active ingredient has not gone away and we know that a dry September and reduced slug pressure last autumn will have been a significant factor in the 2009/10 results – but it could be a completely different story if pest pressure returns to more ‘normal levels’ next season,” he said.
 
Water Catchment Study
Dr Paul Fogg led the water catchment study assessing the relative significance of the three major routes of metaldehyde reaching surface waters. “Direct, point source and diffuse pathways were all assessed and while factors such as direct application into ditches and spillages remain important the study showed diffuse losses through soil drainage, when the field drains are flowing, as being most significant.

“What we found was that moisture moving down through the soil profile will take the metaldehyde from recently applied slug pellets into the network of field drains and from there into the streams, ditches and watercourses which may ultimately lead to a drinking water abstraction point.

The water catchment study showed that of the of metaldehyde ‘losses’ from applications to the heavy clay soils - under worst-case scenario conditions of high rainfall and drain flow - a massive 99% was through soil drains.

The MSG’s Colin Myram explained that a combination of factors can help prevent the problem occurring, which the new best practice guidelines aim to address. “It’s vital that metaldehyde based slug pellets are not applied if drains are flowing or when field moisture capacity is nearing its maximum and heavy rain is forecast. Growers should always aim to use the minimum amount of metaldehyde per hectare up to a maximum of 210g/ha. If further treatment is necessary during the key autumn period alternatives will need to be considered.

“By adding restrictions to applications between August and December it targets the main risk period when weather conditions are most conducive to both slugs and to cause field drains to flow. It is also typically the period when the water companies have detected the exceedances above water quality compliance levels.”

A further amendment to the new guidelines extends the buffer zone requirement when applying metaldehyde slug pellets to six metres, bringing MSG best practice advice into line with other industry stewardship measures.

Notes to Editors:
The Metaldehyde Stewardship Group (MSG) comprises of Lonza (the principal manufacturer of the active ingredient) and slug pellet formulators Certis, Chiltern Farm Chemicals, De Sangosse, Doff Portland, Frunol Delicia, Makhteshim Agan and SBM.

www.getpelletwise.co.uk 

Background information:
The Metaldehyde Stewardship Group was set up in 2008 in response to analysis showing traces of metaldehyde, an ingredient of certain slug pellets, being detected in catchments used for water supply production. At certain periods of the year the levels found could pose a risk to compliance with stringent drinking water standards, even though water companies have state of the art water treatment processes installed.

The UK’s Health Protection Agency and Environment Agency have advised that the levels detected pose absolutely no risk to health or the environment. MSG are engaging the entire agricultural supply chain from manufacturing, distribution and farm users of slug pellets as well as working with the water companies concerned, Water UK, the Environment Agency, The Drinking Water Inspectorate and the CRD (Chemicals Regulation Directorate).

Slugs are UK agriculture’s number one pest and have the potential to wipe-out large acreages of entire crops. Without effective slug control, in years of heavy infestation, significant areas of land would not be able to produce either cereals or oilseed rape – the two most important crops grown in the UK.