Slug pellets are a vital part of the arable farmer’s toolbox in our region. But how do you know which ones to use, and how can we tell if they are effective?

Do you know what pellets you’re using? Are they the most suitable to your conditions and requirements?  I have spoken to a few hundred farmers since joining Anglian Water as a catchment advisor in March this year and I have found that very few of us are aware of what pellets are available and what the differences are between them – dry vs wet and metaldehyde vs ferric phosphate?

Currently in the industry, we have 1.5% and 3% metaldehyde and 3% ferric phosphate pellets.  We cannot use Methiocarb after the 19th September 2015.

The dry processed metaldehyde pellets are the cheapest but they will breakdown quickly due to the manufacturing process and will only last 3-7 days in the field under rainfall. The wet processed pellets are more durable and trials have shown they will last up to 21 days in the field, however they are slightly more expensive per kg.


It is essential to calculate the cost of slug pellets on a per hectare basis rather than looking at the cost per kg.  If you’re having to apply subsequent applications because the pellets are breaking down and disappearing you are losing money down the drain, quite literally.  Do a trial yourself with the wet and dry processed pellets and see which half of the field fairs better and what the cost difference is.

The Water Framework Directive, the Drinking Water Inspectorate and the Metaldehyde Stewardship Group all talk about the impact of metaldehyde on drinking water – it’s a serious issue and one we need to get to grips with. We all have to think water.  Slug pressure increases in wet conditions on heavy land.  Heavy land is drained and it’s estimated that 90% of metaldehyde enters the water courses through field drainage. With metaldehyde being soluble and water treatment processes unable to remove it, should you be looking at using ferric phosphate in these higher risk situations?


Ferric phosphate, whilst being slightly more expensive, has been proven to be as effective as metaldehyde and is insoluble in water with no known adverse effects to water quality.  If farmers are using ferric phosphate in higher risk areas, they could help protect the use of metaldehyde for lower risk areas.  Ferric phosphate works in a different way to metaldehyde. When a slug digests metaldehyde, the slug produce surplus mucus and dies on the surface, when a slug digests ferric phosphate, the slug will stop feeding immediately and will go underground to die, so you will not see the mucus or the dead slug.

To have any chance of keeping metaldehyde in our tool box, we must look at using alternatives in high risk areas where run off and field drainage are more likely to impact on drinking water quality.

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Posted by anglianblog