The Manure Matters website lists a number of vegetable types affected by aminopyralid. I wondered "are there plants it doesn't affect - so we can use our suspect stores of manure with impunity?"...So I asked Dow, here is their reply (received within 2 days of my mail)...
Message starts -
Thank you for your enquiry about the relative sensitivity of different plant species to the herbicide active ingredient aminopyralid.
On the ManureMatters website we have tried to list the plant species we know to have greatest sensitivity to aminopyralid. Your question about plants which might be less sensitive is interesting and we will look to add the information below to the website. Thank you for raising it.
Sensitivity or tolerance to any herbicide is dose-dependent, so this list is drawn up in the context of the likely amounts of aminopyralid found in manure that might be used in gardens or allotments. Plant species which exhibit less sensitivity to aminopyralid include:
· Grass
· Sweetcorn
· Brassicae (e.g. broccoli, cabbage, cauliflower)
· Established top fruit trees (e.g. apples, pears)
Cane fruits, such as raspberries, gooseberries, blackcurrants, redcurrants and whitecurrants do show some sensitivity to residues of aminopyralid, but not to the same degree as potatoes, tomatoes, carrots and legumes.
I hope you find this list useful.
Message ends.
And follwed up with another message...
Message starts:
"We will endeavour to add to the list of less sensitive crops, but as you know the variety of crops grown on allotments is vast. Are there any particular crop types that you have in mind that you have not already mentioned?
But please remember the earlier response which said that plant sensitivity or tolerance is a dose dependent. It is unlikely that the crops previously mentioned will be greatly affected but it is not a guarantee."
Message ends
I guess we can assume that "less sensitivity" means safe since the website calls for horse owners "to ensure that it gets spread on grassland or land destined for grass, cereals or maize."
So if any one has a list of vegetable types not mentioned above please post a reply to this thread and I'll collate them over the next few days and forward them to Dow,
Hope this helps.