With limited capacity to produce ferric phosphate in Europe for the UK market and the country’s metaldehyde stock levels unknown, should there be a high pressure slug season this autumn and further ahead, UK farmers could find themselves struggling to source slug pellets.
When the UK government ban on metaldehyde was announced on December 19, 2018, De Sangosse managing director Dr David Cameron says he was ‘absolutely astounded’. “I never expected an outright ban. We had worked hard on stewardship through the Metaldehyde Stewardship Group. Not just manufacturers but distributers, the NFU, farmers, AIC and AICC agronomists.”
From announcement of the ban, no metaldehyde can be manufactured for the UK market, including imports, and products containing it can only be sold until June 30, 2019. A 12-month use-up period will follow, explains Dr Cameron, who is trying to get a handle on what stocks are available.
The only alternative chemical method for slug control is ferric phosphate, which concerns Dr Cameron from an availability and potential resistance point of view. “Until a little while ago we also had methiocarb – now we are down to one mode of action.”
While Dr Cameron says he does not expect resistance problems, ferric phosphate will not have been used on such a wide scale before and ‘nature has a way of fighting back’.
The company’s Ironmax Pro (ferric phosphate) has recently been reapproved for 15 years as a low risk product and Dr Cameron does not expect any environmental issues but says: “You never can tell and it’s always best to have an alternative mode of action.”
He believes alternative modes of action are unlikely to be forthcoming because of the high cost of bringing pesticides to market and that slugs are a relatively minor problem internationally, although a major problem for the UK, France and Germany. “The rest of Europe can use metaldehyde. Why would companies bring forward another when they already have two. The UK could lose out as companies are unlikely to develop a new mode of action just for the UK market.”
Availability of ferric phosphate is also a concern, says Dr Cameron. “With slug protection, every 3-4 years there is very high demand and demand can double or triple overnight. Should this happen I can’t answer as to whether there will be enough pellets available to satisfy UK demand.”
While there are 13 plants in Europe manufacturing metaldehyde pellets, there are only two producing ferric phosphate pellets, he says. “Until we have a large slug pressure year we won’t know. They are quite bulky products and have a finite shelf-life – they can be stored for two years so you can’t build up a huge stock. There are huge costs associated with manufacture and storage.”
ADAMA marketing and technical director Alison Bosher expressed disappointment at the decision to ban metaldehyde but added: “ADAMA is well on its way to developing new molluscicides using alternative modes of action and will be bringing these new products to market over the next couple of years.
Certis marketing manager Nathan Whitehouse says currently he does not foresee any issues with ferric phosphate availability and says this autumn will be a key season for growers to look at their slug control programmes and gain familiarity with the active ingredient and how to use it going forward.
He adds: “There needs to be more onus on looking at integrated control using products as and when they are needed. Certis has the SlugWatch app which offers local forecasting of slug pressures.”
David Cairns, agrochemical director at distributer McCreath, Simpson and Prentice, based in Northumberland, where drilling tends to be in September when slug pressure can be high, says he has seen good results with ferric phosphate.
“We have been using it very successfully over the last 2-3 years. Based on personal observation it is equal to if not more successful than metaldehyde. The [slug] damage stops immediately and there is equally as good or better knockdown and the pellets seem to be more persistent.”