If your garden vegetables are showing symptoms similar to that shown on the left then they might be a victim of something called aminopyralid poisoning. The problem is caused by the residues of a hormone mimicking pesticide called aminopyralid which is used by farmers to kill weeds growing in fields of grass.
Government approval for the pesticide was suspended in 2008 after cases of cross contamination but it appears farmers are still able to use it under strict guidelines. This includes spraying it only on fields which are grazed directly by cattle and not on fields where silage or hay is grown. Manure from animals kept in the pastures should be used only on the farm and farmers must confirm in writing that they have been instructed in the use of the pesticide and in manure management issues. All of these measures should be enough to prevent further issues of cross contamination but it appears this is not the case.
The article highlights the case of a market gardener who lost their entire crop of vegetables to this curling disease. The problem was that the manure they had used was contaminated. It seems that somewhere in the process someone had not followed the stringent guidelines related to the use of aminopyralid. It seems many cases of this poisoning are simply put down to other factors such as poor weather and diseases and so go unreported with many gardeners unaware of the problem or indeed the real reason why their crops might have failed. Reading this I am reluctant to purchase any manure without knowing where it has been sourced from and think I may stick to simply using compost from the garden.