Date: Tue, 4 Apr 2000 09:03:14 -0700 (PDT) From: Barry Meyers-Rice <bamrice@ucdavis.edu> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1009$foo@default> Subject: Using poison on introduced carnivorous plants
Hi Dave,
I help advise natural area land managers (in particular, staff of The
Nature Conservancy) across the US on ways of managing and eradicating
invasive, non-native species from their preserves. This conversation on CP
weeds is right up my alley!
Anyway, the thing to remember when applying a control method is that
anything you do causes damage. Herbicide *is* a poison, manually
pulling causes soil structure damage, grazing and fire have significant
incidental effects, etc. So you try to maximize your damage to the weed,
while minimizing your impact on the native biodiversity.
The Drosera capensis plants in California would be quite difficult to
remove by herbicide because, as you note, the water is so plentiful. An
herbicide and application method would have to be designed carefully so
you do not hit non-targets. Unfortunately, the exotics are growing among
grasses and trees, and these could be damaged by herbicides, too. The
presence of (native) D. rotundifolia complicates the matter.
Incidentally, please note that not all herbicides are the same in terms of
toxicity, selectivity, or motility and persistence in the environment. The
herbicides that I would consider for this sort of situation would have to
be those that are broken down within the target plant, and would also have
to be ones that are rapidly decomposed in the environment by microbial
action. The choice of an "environmentally appropriate" poison (sounds odd,
but it can be done) is essential. Not all herbicides have the same
attributes.
The more I think about this, I think that the best thing to do would be to
map the infestation, and try manual removal as much as you
can---preferably during a wet time of the year so you get as much root
mass as you can. If that didn't work, I'd look at using a brush or wick
applicator like you mentioned.
HOWEVER, before you could do any of this, you'd have to investigate the
ownership of the land. You have to have permission to do restoration on
land that is not your own, and you especially need permission to apply
pesticides on land you do not own!
As for the Utricularia subulata infestation, I think you are just out of
luck. This species is probably intractable. I am also interested in the
greenhouse thrips and other insects which have been introduced at this
site. I wonder what will happen if these pests make it to the native
Darlingtonia populations?
Barry
--------------------- Dr. Barry Meyers-Rice Assistant Weed Specialist
The Nature Conservancy 530-754-8891, bazza@ucdavis.edu
http://tncweeds.ucdavis.edu
> Well, instead of pulling these weeds, how about using poison? I know
> that this may threaten nearby plants, especially since there is so much
> water in these areas, but if a systemic herbacide could be applied with a
> brush to the offending rosettes, so much more damage would be done to their
> population.....
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