Contaminated manure update
6 August 2008
The chemical, aminopyralid, thought to be responsible for contaminating manure and destroying vegetable crops has been withdrawn at least temporarily at the request of the manufacturer Dow AgroSciences, while The Pesticides Safety Directorate (PSD) investigates how and why contaminated manure made its way to allotment holders and gardeners. In the meantime it cannot be sold, supplied or used.
The RHS was alerted to the problem in June when members were calling for advice on why their vegetable crops were growing abnormally. See original story posted 17 June.
On 11 July, an announcement from the Pesticide Safety Directorate reassured gardeners that produce from affected land was safe to eat. This was followed on 23 July by the news that, at the request of the manufacturers, all products containing aminopyralid had been withdrawn from supply, sale and use while the PSD investigated what went wrong.
Since then, gardeners have reported instances of some crops growing out of the problem and guidelines to dig over contaminated ground several times between now and the autumn should ensure the soil is safe to plant by spring 2009.
Guy Barter, RHS Head of Horticultural Advisory Services, still has this word of warning: "It is unlikely that the current suspension of aminopyralid is going have immediate effect. Batches of contaminated manure will continue to be in the supply chain for at least the next year or so and gardeners should remain vigilant about using manure from sources that cannot confirm that it is free from persistent weedkillers such as this.”
The RHS gardening advice service recommends that unused manure be returned to the supplier, or left to rot down for at least several years or as a last resort disposed of as waste.
An advisory note for gardeners can be found on the Dow AgroSciences website which manufactures aminopyralid.
Or email ukhotline@dow.com if you need further help.
For more advice on contaminated manure, see the RHS Advice profile: weedkiller in manure