Extreme caution urged with metaldehyde

The Metaldehyde Stewardship Group (MSG) has again stepped-up the message to take extreme care with applications of metaldehyde slug pellets as Water UK reveals concerning levels of detections of the substance in streams, rivers and reservoirs across England.

Speaking at a briefing meeting this week the MSG’s Dr Paul Fogg explained that the results from monitoring by water companies – that represent a geographic spread across England – followed periods of heavy rainfall that have been a feature of the last month’s weather conditions.

“The situation is a clear culmination of circumstances where wet weather, a poor harvest, difficult establishment conditions and protracted crop growth have provided the ideal environment for slugs to thrive and breed. Meanwhile the usual ‘cultural controls’ such as rolling and generating a fine seedbed to deter slugs have been impossible to implement because of poor soil conditions. Crops that would normally have been in the ground for some time and that should be well established by now, remain vulnerable to attack as they have been slow to grow in the cold soil,” he said.

Gloucester based NFU farmer James Cox added that; “Growers and operators have been in an untenable position in reconciling protecting valuable food producing crops from certain decimation, and abiding by metaldehyde stewardship. From my own experience and what other farmers tell me, the slug pressure is at its worst for a decade.”

Phill Mills of Water UK explained that water companies take regular samples of river and reservoir water to monitor the levels of metaldehyde. 

“Since late September this year, a number of companies have reported to the MSG that levels of metaldehyde have significantly increased in rivers and reservoirs across much of England,” he said. “The levels have greatly exceeding the 0.1 parts per billion (ppb) standard for drinking water, which is the threshold for the majority of individual pesticides.

“Peaks in metaldehyde have reached over 4ppb in several water catchments, with some river samples recording their highest ever value since intensive monitoring began in 2008,” reported Phill.

He added that the issue for water companies is that metaldehyde is particularly difficult to remove from water, even using existing advanced water treatment processes, which can ultimately lead to exceedances of the standard in drinking water supplies.

“This is certainly a serious situation,” noted Phill. “But, it needs to be taken in the context that the 0.1ppb standard is not determined on a health or environmental basis, but is defined as the ‘near-zero’ value, reflecting EU legislation that sets out that pesticides should not be present in drinking water.

 MSG Chairman Dr David Cameron reiterated the MSG’s commitment to promoting best practice stewardship at farm level to prevent exceedances occurring. “Since the formation of the Group in 2008 a number of important measures have been introduced. They include the removal of the highest dose metaldehyde products, the addition of a statutory maximum rate of 700g/ha/year on the label, and the introduction of voluntary restrictions for doses applied as single and seasonal treatments.

 “Specific operator training – the PA4S – has also been introduced; a 6 metre buffer zone set; and guidelines issued that clearly set out the conditions under which metaldehyde should not be used – such as when heavy rain is forecast and when drains are flowing. This has all been supported by the high profile ‘Get Pelletwise’ campaign to raise awareness and ensure best practice is communicated and understood.

“Today, the urgent need to abide by MSG best practice is more pertinent than ever,” added David.

Hazel Doonan of AIC (Agricultural Industries Confederation) stated that the AIC members have made a firm commitment to the MSG campaign, with agronomist members highlighting the importance of following the MSG stewardship measures to growers and members endeavouring to supply a range of   alternatives where metaldehyde cannot be used. “It is vital that the industry retains a number of active ingredients for slug control to allow products to be alternated in the interests of sustainable and long-term pesticide best practice. It is also important in terms of ensuring a constant supply of slug pellets in circumstances where demand can fluctuate drastically depending on the conditions of the season.”

In a Briefing Paper, Water UK set out that the water industry remains committed to working with the MSG, regulators and agricultural stakeholders to ensure that metaldehyde does not reach watercourses, and fully support the voluntary measures and catchment management approaches being taken. However, if a voluntary approach does not generate sustainable reductions in levels of metaldehyde in rivers then restrictions may be imposed to protect essential water supplies.


Metaldehyde Stewardship Group best practice

Application guidelines

• Use minimum active per hectare to avoid drainage and runoff losses

• Maximum application rate 210g metaldehyde a.s./ha* For additional protection of water, suppliers/BASIS advisors may recommend rates reduced to 160g a.s./ha or less*

• Maximum total dose from 1st August to 31st December: 210g metaldehyde a.s./ha* For additional protection of water, suppliers/ BASIS advisors may recommend rates reduced to 160g a.s./ha or less*

• Maximum total dose rate: 700g metaldehyde a.s./ha/ calendar year*

• No pellets to be applied within 6 metres of a watercourse

• 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



Notes to editors:

The Metaldehyde Stewardship Group* (MSG) 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 abstraction.

Certain periods of the year levels found in some water bodies could pose a risk to compliance with stringent drinking water standards. The entire agricultural supply chain is engaged.

Best practice guidelines have been put in place and there is a statutory maximum of 700g/ha calendar year for metaldehyde. In addition, the MSG have set an autumn restriction period (1 Aug- 31 Dec) when total doses are restricted to a maximum total application rate of 210g/ha of the active ingredient, which may be reduced to 160g/ha or less upon the recommendation of a BASIS qualified advisor.

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

The Metaldehyde Stewardship Group (MSG) represents 100% of the UK agricultural market for metaldehyde slug pellets and comprises the manufacturers; Certis, Chiltern Farm Chemicals, De Sangosse, Doff Portland, Frunol Delicia, Lonza and Makhteshim Agan.

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