Midmar Allotments have received the following helpful communication from the Health and Safety Executive that may be of interest to allotment holders:

While it is likely that the abnormal leaf development has been caused by aminopyralid residues in the manure, you should also consider that other factors might also cause leaf damage such as lack of water and frost.

If the manure came from a farm, you might be able to confirm whether the farmer used an aminopyralid product such as Forefront on grass which was then either grazed by his cattle or cut for hay or sileage and fed to his cattle over winter (probably Winter 2008; it is also possible that he bought in hay or sileage from elsewhere, in which case you would also
need to try and trace back to the original farm to see if that farmer had used an aminopyralid product.

If the manure came from a stable, then you will need to ask the same questions though it is much more likely in this case that hay or haylage would have been bought in. If the stable offers DIY livery where owners bring their own hay in, the tracing back to find the aminopyralid becomes very much more difficult.

I'm afraid it is not possible to predict whether affected crops will
fail; this will depend on the sensitivity of the crop to aminopyralid, the amount of aminopyralid present, and the rate at which the aminopyralid is released into the soil (which depends on yet other factors, including soil conditions, temperature and rainfall). Crops such as peas, beans and other legumes, carrots and parsnips, potatoes and tomatoes, and lettuce and similar crops are most sensitive to aminopyralid and therefore most likely to be affected whereas crops such
as sweetcorn and squashes, courgettes and marrows are less sensitive and more likely to survive.

Basically, the aminopyralid is held in the remnants of the treated grass which, having passed through the livestock which produced the manure, form part of the manure. As these grass remnants decompose, they release aminopyralid which then becomes available for take up by any plants growing in the soil; it also becomes available to bacteria in the soil which will then deal with it by breaking it down into simple substances. If aminopyralid is present, it will not be necessarily be present at the same levels throughout the manure; nor will it be released at the same rate (or even a constant rate) throughout the affected area. You might therefore find that some crops are affected early on but then recover (because there's no more aminopyralid left in
that are while other crops appear to be growing well and then succumb later on.

If the manure has been incorporated into the beds, there is little that can be done. Your choice is either to wait and see if the crops recover and produce some sort of harvest or to dispose of the crop now and leave the beds empty until autumn at the earliest, ensuring that the beds are thoroughly dig over every few weeks - the more the manure is dug in, the more it breaks down, releasing any aminopyralid to be dealt with by the soil bacteria. With this method, the aminopyralid will eventually disappear although it is not possible to say exactly how long this might
take.

If the manure was added to the surface but not actually dug in to the bed, then it should be removed from the beds and stacked somewhere temporarily; it should not be composted or recycled in any way. There are several options for disposal:

* see if the supplier will take it back;
* see if you can find another farmer who will take it (it can quite
safely be added to grazing land);
* contact your local council to see if you can dispose of it through the normal channels - you will need to let them know that it contains aminopyralid and probably needs to go to landfill;
* dispose of it via a commercial licenced waste disposal operator (it is not hazardous but it has been contaminated with chemicals so needs to be disposed of properly); again, you will need to let them know it contains aminopyralid and should not be diverted into any composting or manure
processing operation;
* contact Dow AgroSciences at ukhotline@dow.com who might be willing to arrange for its collection and disposal.

When you come to consider whether to use the beds again, it will be worth trying some test germinations; Dow suggest broad beans - see "What can I do? On the right hand side of
http://www.manurematters.co.uk/gardening.htm for details of a simple structured test. If the plants show signs of distortion, this is an indication that the bed is not yet ready; if the plants appear to be growing properly, this indicates that it might be possible to use the bed but does not demonstrate conclusively that no aminopyralid is present.

If anyone does eat produce from affected plants, this should not pose a risk to their health. Based on reasonable worst case assumptions – that cattle are only fed grass treated with aminopyralid (or silage made from grass treated with aminopyralid), that vegetables are grown in soil
mixed with manure produced from the animals, and that all the
aminopyralid released from the manure is taken up into the plants, the highest residues would not be a concern for health, so vegetables should be safe to eat. Dow AgroSciences also provided information on studies of residues in treated food crops which indicates that actual residues will be much lower than estimated, which gives additional reassurance.
Aminopyralid is an effective herbicide/weedkiller, but of low toxicity to mammals. We do, however, appreciate that not everyone will be happy to eat food produced in these circumstances and that they will prefer to dispose of any crops.

You will find further information on the aminopyralid problem on our
website at http://www.pesticides.gov.uk/safe_use.asp?id=2465,
http://www.pesticides.gov.uk/safe_use.asp?id=2480,
http://www.pesticides.gov.uk/approvals.asp?id=2501 and
http://www.pesticides.gov.uk/safe_use.asp?id=2529, and on the Manure
Matters website at http://www.manurematters.co.uk/. Susan Garrett, Chair of Green Lane Allotments in Wakefield , West Yorkshire , has put a lot of time and energy into collating and compiling information about the problems caused on allotments by aminopyralid residues in manure so you may find further useful information on the allotment website at
http://glallotments.co.uk/default.aspx (follow the link to "Contaminated Manure" in the navigation bar).