I have copied this from the commondreams website via the Grauniad/Observer
here is the original link
http://www.guardian.co.uk/environment/2008/jun/29/food.agriculture

Home-Grown Veg Ruined by Toxic Fertiliser

by Caroline Davies

Gardeners have been warned not to eat home-grown vegetables contaminated by a powerful new herbicide that is destroying gardens and allotments across the UK.0629 03 1

The Royal Horticultural Society (RHS) has been inundated with calls from concerned gardeners who have seen potatoes, beans, peas, carrots and salad vegetables wither or become grossly deformed. The society admitted that it had no idea of the extent of the problem, but said it appeared ’significant’. The affected gardens and allotments have been contaminated by manure originating from farms where the hormone-based herbicide aminopyralid has been sprayed on fields.

Dow AgroSciences, which manufactures aminopyralid, has posted advice to allotment holders and gardeners on its website. Colin Bowers, Dow’s UK grassland marketing manager, told The Observer that links to their products had been proved in some of the cases, but it was not clear whether aminopyralid was responsible for all of them and tests were continuing. ‘It is undoubtedly a problem,’ he said, ‘and I have got full sympathy for everyone who is involved with this.’

He said the company was unable to advise gardeners that it was ’safe’ to consume vegetables that had come into contact with the manure because of pesticide regulations. ‘All we can say is that the trace levels of aminopyralid that are likely to be in these crops are of such low levels that they are unlikely to cause a problem to human health.’............................

How to deal with the problem

Do you have contaminated manure?
Tell-tale symptoms of crop damage include distorted foliage, with cupping of leaves and fern-like growth. There are no remedies once damage has occurred. Susceptible crops include potatoes, tomatoes, beans, peas, carrots and lettuce.

How should you deal with the affected area?
Experts say rotavation is the best practice, or forking over several times as soon as possible. This incorporates the plant tissue into the soil, where it will decompose and the chemicals will eventually be degraded by soil microbes. Repeat the rotavation in late summer/early autumn.

Should you replant this season?
No. The plant residues need to be given time to break down. The advice is not to replant for a year.

Why has the chemical lasted so long?
Aminopyralid, like other herbicides, works by binding strongly to plant tissues. Once the plant’s tissues decay, the chemical breaks down in the soil. If manure is stacked it takes far longer.

guardian.co.uk © Guardian News and Media Limited 2008