In June 2008 a group of plot holders on our site noticed that potato and tomato crops were not growing well. Both types of crop were displaying distorted leaf formation. We realised that the problem was confined to areas where plot holders had applied manure which had been purchased from the same supplier which indicated that the manure was the source of our problems. This instigated more investigation and we discovered that the problem, which was identified as likely to be hormonal herbicide contamination, was not just affecting our allotment site. It also seemed that the contamination was not confined to manure as some reported that bagged compost seemed to be affected.

I decided to post information on my website so that others having problems had access to all the information that we had managed to gather. The suspect herbicide aminopyralid had its licence withdrawn by the manufacturer and after they drafted a improved stewardship the Chemicals Regulations Directorate (CRD) - formerly Pesticide Safety Directorate reapproved the licence. This means that the chemcal is back in use so we need to be vigilant in monitoring whether the new stewardship is affective. An information sheet offering advice to anyone obtaining manure can be accessed here

The pages linked form here tell the story in full and hopefully the photographs and video helped in identification of the problem.

Cupping of leaves upwards is a typical sign of hormonal herbicide contamination. New growth may take on a fern-like appearance. Leaf texture may become leathery and veins may appear more prominent. In some plants the veins will be parallel to one another.  

Just for reference the potato council has photos of symptoms of the many pests and diseases that can affect potatoes click here

Press release from DOW AgroSciences 17 June 2010

Reintroduction of aminopyralid products will not lead to more manure problems

Aminopyralid herbicides have been re-introduced this year to help grassland farmers deal with difficult to control weeds but with tight controls to prevent problems with manure management.

Aminopyralid herbicides are the most effective solutions to control dock, thistle, nettle, and buttercup infestations in grassland. To ensure that their use does not lead to a repeat of the issues seen previously, their availability is now tightly controlled with a significantly amended label and a stewardship scheme which ensures farmers are aware of the implications for subsequent manure management. The herbicides cannot be used on grassland destined for hay and silage nor on grassland grazed by horses. This year sales are restricted to Scotland, South West England and Northern Ireland.

There have been some incidents this year of manure containing aminopyralid ending up on gardens and allotments.

“This is disappointing and upsetting for those affected,” said Dow AgroSciences principal biologist Andy Bailey. “Although of small comfort, we would reassure anyone affected that this manure has not come from use this season under the new controls. It is a reflection of manure generated from past treatment and kept in heaps for more than a year. Also, the past long winter means old stocks of forage will have been consumed on livestock farms.”

The new restriction in aminopyralid use will mean any manure returns immediately to pasture where it will cause no harm and cannot leave the farm. The stringent use restrictions are explained in detail to every professional farmer who wants to buy a product and a written confirmation of understanding must be completed.

Dow AgroSciences’ advice to concerned farmers or gardeners remains the same – to check carefully the provenance of any manure being used where sensitive crops, such as potatoes, peas, beans and carrots, may be grown.

“If anyone supplying manure cannot state with certainty that no aminopyralid-based product (sold as Forefront, Pharaoh or Banish) was used on the forage from which the manure resulted, then it is best not to accept any supply,” says Mr Bailey. “For anyone who has manure and is concerned, please contact us through our dedicated website http://www.manurematters.co.uk.This site also contains detailed information and frequently asked questions for gardeners, horse owners and professional grassland farmers.”

Additional information:

I couldn't find any information on the new labelling for the UK but found this information with respect to Canada click here

Herbicide packaged before the reintroduction have been recalled see here

Question:

Anyone know why sales are being restricted to Scotland, South West England and Northern Ireland?

Back to top of page