On Thu, Mar 21, 2013 at 10:36 AM, randy oliver <[log in to unmask]>wrote:

>
> Dan, I suspect that the contamination in the dandelions was due to planting
> dust falling on the blooms, as opposed to uptake from the soil.  This would
> be a temporary phenomenon.


Why do you think that?  Some French studies on sunflowers showed carryover
in the soil into the next year.  In fact,  it was a problem because the
fields of sunflower that had been designated as the control fields (not
treated in that year, but treated previously) showed levels of imidacloprid
in sunflower pollen almost as high as treated fields.  In potatoes Jim Kemp
found levels of imidacloprid in canola following potatoes that had levels
of imidacloprid in both pollen and nectar (from the previous years potatoes
carrying over in the soil) about the same as levels of thiamethoxam which
the canola had been treated with.

Why do you doubt the data on half life?  You said you corresponded with the
author of the British study on soil accumulation, did you have a particular
problem with his methodology or results?

Stan

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