Topic: Aminopyralid and calcium

[Digeroo]

Does anyone know whether the presence of Calcium makes the effects worse?

We are having quite a problem on site this year but there are some very odd effects.  I have broad beans that have been fine and then started to get a problem five feet high.  Some people are having more problems than others.  Some people have potatoes had are growing through the problem and the leaves are unfurling and other people not.  There is even one person with beans that have a problem but are being grown on land that has not been manured this year but grew potatoes without problem last year. 

[Tee Gee]

Does anyone know whether the presence of Calcium makes the effects worse?

I can only give an opinion on this as I am not qualified in the subject.

Calcium is used as a pH adjustor and a plant that is growing at its optimum PH value will grow 'differently (good or bad) if the pH is wrong for it.

Meaning that if the soil is in good fettle the plant will take up nutrients better than a plant that is growing at the wrong pH.

So its feasible that it may take up Aminopyralid faster or slower as well.

So my guess is;  the variations in problems will have some relationship to the pH values on each of the plots, i.e. pH values are most likely different on each plot!

As I said this is only an opinion!

BTW I have sent my problem to the RHS advice Dept (I am a member) and they say it is most likely Aminopyralid based.

What they haven't told me is what to do with the affected plants or why other plants that are in contact with the same manure seem not to be affected. ???

I await a further reply so watch this space!

[Digeroo]

Many thanks for your post

I am beginning to think that using tap water is somehow making the problem worse.  The only thing that this contains is a high level of calclium carbonate.  Being well water it has no chlorine etc. 

I was beginning to think that the dry conditions were to blame but that would not explain the differences between neighbouring plots. 

I am interested in whether people who you have had problems have acid or alkaline soils.

[realfood]

In Glasgow last year it was in acid soils. The rate that it affects plants probably  depends on how suitable the soil conditions are for the breakdown of the grass fibers by the soil bacteria. For instance in dry conditions like this year, it will take longer for the bacteria to get to work. Warmth and moisture will hasten the process.
The reason why some of the first leaves of affected plants look normal, is that the aminopyralid has not been released as it is still locked up in the grass fibres. As the soil bacteria get to work on the contaminated manure and breaks down the remains of the grass fibers, aminopyralid is released to do the damage to potatoes, peas, beans, tomatoes, lettuce, carrots, rasps in particular.
After several weeks, the worst of the aminopyralid has been released and washed down by rain, and the plants start to grow again provided the concentration of aminopyralid is not too great.
There have been several reports of dissolved aminopyralid in the ground water, affecting plants many metres away from stored manure.