[APWG] Knapweed control, other than insects = Cryptic Indigenous Pathogens?

[Craig Dremann]

TO: Scott Ruhren, Ph.D.
Director of Properties and Acquisitions
Audubon Society of Rhode Island
12 Sanderson Road
Smithfield, RI 02917-2600

401-949-5454 (Ext. 3004)

Scott's request: "By the way, I would love to hear about knapweed
control agents other than insects released by USDA et al."


Dear Scott and All,

While searching at the patent office many years ago, I came across a
patent filed by a Hawaiian researcher on the discovery of a pathogenic
fungi that killed knapweed, and if I remember correctly, it was an
indigenous fungi, not an introduced species.  If you search the US
Patent office for "Knapweed", that word was in the title of the patent,
and it was issued about 15-20 years ago.

The patent was assigned by the Hawaiian researcher to the Colville
Indian tribe in northern Washington State, I think with the hopes that
they might find the funds to develop this patent into something that
could control knapweed on their reservation lands, and also provide a
source of income for the tribe, via the patent licensing fees.

Unfortunately, I think that this patent has been so obscure and unknown
to even the biological control community of researchers and businesses,
that nothing commercial has ever been done with it so far.  Maybe
somebody on the list has an update on the patent and the commercial use
of the fungi pathogen that was patented?

Usually, all the biological control agent researched and developed for
exotic plants, are the introduction of exotic insects or exotic
pathogenic fungi, imported from the country of origin of the exotic
target species.  I think there needs to be a lot more investigations on
the existence of the potential Indigenous pathogenic fungi of North
America.

For example, many years ago, I discovered that there is a part of
California where neither wild oats (Avena fatua) grew, nor where any
eucalyptus seedling could survive---and the local native ecosystem was
in the most excellent shape.  It was almost like the native ecosystem
was charged with "Antibodies against Exotics".

And that idea proved correct, when I discovered that there is an
indigenous pathogenic fungus in the soil---and it didn't wait to attack
the wild oat plants like most fungi pathogens do, but instead killed the
seedlings as they were trying to germinate!

In order to propagate, this fungus must reproduce benignly within the
native ecosystem, just like we humans always have pathogenic staph
bacteria on our own skins that don't cause us symptoms of infection. 
You could call this a "Cryptic Indigenous Pathogen", because you don't
see obvious evidence of its existence.  

By conducting petri-dish tests with cultivated oat seeds, you could see
the oats being killed as soon as the roots started emerging from the
seeds---and in situ, the pathogen was 100% successful in keeping the
area completely free of wild oat plants.   

Of course, wherever this pathogen occurs, you couldn't ever grow a crop
of cultivated oats---but I'm just trying to show an example of the
successful action of an Indigenous pathogenic fungi, that it can be just
as effective as an exotic introduced one. 

So, instead of continuing to import and introduce exotic pathogens for
biological control, perhaps we could start a search for these "Cryptic
Indigenous Pathogens", which may be already ready and willing to work
for the health of their native local ecosystems---if we can only
recognize that they are there?

And perhaps this wild oat/cultivated oat pathogen is suggesting a future
cultivated area/wildlands dichotomy?  

Whereas native plants are usually completely excluded from cultivated
areas,  we may need to utilize materials in wildlands ecosystems, that
will strengthen ecosystems to the point that they will have the
equivalent of “antibodies” to resist exotic plant invasion ---but then
will also be strong enough to exclude our related cultivated plants?

Sincerely,  Craig Dremann, Redwood City, California USA (650) 325-7333