[Market-farming] treated seeds consequences

Bill Shoemaker wshoemak at inil.com
Thu Jun 12 15:54:58 EDT 2008

Unless you plant on a massive scale and use lots of the seed treatment, it 
will probably biologically degrade before it causes any groundwater 
problems, especially if you feed your soil through composting, green 
manures, animal manures, etc. The microflora are actually quite capable of 
"feeding" on these substances to break them down and use the energy 
released. Most groundwater contamination results from massive, repeated use 
of pesticides, particularly herbicides. Also, they are not usually systemic, 
meaning the plant does not take them in. They will remain outside the plant 
and in the soil. The beans you harvest will not be contaminated and the 
shoot system will have no residues. They stay with the seed remnants.

Bill Shoemaker, Sr Research Specialist, Food Crops
University of Illinois - St Charles Horticulture Research Center

> Folks: I inadvertedly planted some seeds, unmarked, that were treated. My
> questions: what effect does this have? I know it will "pollute" the soil
> and eventually drain into the water table. But what will it do to the 
> plant
> (bean)? Will there be residue in the beans themselves? Should I destroy 
> the
> plant after harvest instead of putting it into the compost pile or 
> tunrning
> it in?

Do you know what the seeds were treated with? If beans, I'm guessing most 
likely it was a fungicide. Here's a website with some information that may 
be useful:


I don't know how the organic regs deal with this question, but if that's not 
a concern, my own inclination would be to not worry any more about it. The 
amount of fungicide per seed is quite small. It is likely to be largely 
confined to the seed coat, which will either remain in the soil after the 
cotyledons emerge, or to be dropped off by them as they sprout. Any small 
amount that penetrates to the cotyledons or the root tip would be so small, 
that it is likely to be dwarfed by the toxins we all ingest daily from just 
living in the world we do. I don't know what the half-life of the chemical 
used is, but it's pretty likely that, by harvest time, it's all broken down 
anyway. I wouldn't worry at all about composting.

If you really want something to worry about, ask yourself (as I do) what the 
effect is of all that rotenone we've been exposed to. Rotenone is used to 
induce Parkinson's disease in rats.

 Richard Robinson

Market-farming mailing list
Market-farming at lists.ibiblio.org

More information about the Market-farming mailing list