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Date: | Sun, 20 Jul 2008 11:25:32 -0400 |
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> This is not a fight we can win.
We certainly cannot eliminate or cure all disease,
just as we cannot hope to eliminate all pests of
plants.
But I think it is important to realize that
more than antibiotics and pesticides can
prompt "resistance".
The discussion about "Pesticides on Sweet Corn"
prompted me to recall that the corn rootworm
in the Midwest became "resistant" to not a
chemical or drug, but a simple cultural practice.
(I like early corn, so I keep up on the R&D.)
If corn was rotated annually with soybeans, it was
not infested with rootworm larval damage because
western corn rootworm laid eggs only in cornfields.
Also, rootworm larvae could not survive on soybean
roots, so any larvae that hatched from eggs laid in
corn the previous year simply starved.
So crop rotation was the best tactic for managing
western corn rootworm. But the rotation of corn and
soybeans for decades in Illinois resulted in the
emergence of a new strain of rootworm which lays
its eggs in soybean fields.
All this is very recent - 1995! Rootworm damage in
corn crops rotated with soybeans appeared, and
when samples were taken, rootworm adults were found
in both corn and soybean fields. Tests on the new
rootworm variant show that it also lays eggs in
alfalfa, oat, and even wheat stubble.
The mutants with less "picky" tastes survived,
and the main population of the pest became
dominated by pests with the mutation.
This is a serious problem for corn farmers, but it
does at least annoy the heck out of the creationists
in the Midwest, as it is a prima-facie example of how
a creature evolves, and can evolve quickly (over a
span of mere decades) if conditions change suddenly.
As a result, creationist corn farmers are now an
endangered species themselves, and must evolve.
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