Pubdate: Mon, 24 Jul 2000
Source: Reuters
Copyright: 2000 Reuters Limited.
Author: Diane Bartz

US PRESSES COLOMBIA TO USE HERBICIDE ON COCA

WASHINGTON (Reuters) - The United States is pressing Colombia to use a
controversial fungus to kill coca plants, U.S. officials and others familiar
with the program say.

Advocates of the fungus Fusarium oxysporum, such as Florida Republican Rep.
Bill McCollum, see it as what he calls the ''silver bullet'' that can defeat
coca and win the war on drugs.

The hope is that eradicating Colombia's coca industry will cripple a
guerrilla movement that controls up to 40 percent of Colombia, where a
30-year internal conflict has left more than 35,000 people dead since 1990.

The program's supporters say the fungus kills only coca, used to make
cocaine, and opium poppy, used to make heroin, without hurting food crops.
But its detractors warn that using even an apparently benign biological
agent can damage the environment and possibly hurt the farm families who
grow coca.

While various strains of Fusarium have killed coca, tomatoes, corn and a
host of other crops for decades, this particular strain was discovered
accidentally when it decimated a coca crop in Hawaii that researchers
planned to use to test chemical herbicides, said Eric Rosenquist, head of
international programs at the Agriculture Department's Research Service in
Beltsville, Maryland.

Rosenquist said the next step was to do field tests in Colombia to determine
if the fungus killed enough of the coca it attacked to drive farmers into
planting other crops, usually 40 to 50 percent.

``Conceptually it seems to work,'' he said, adding: ``It certainly is not
ready to use.''

But Colombia has balked at field trials, and Environment Minister Juan Mayr
said in Madrid in early July that Bogota believed Fusarium may pose
``serious risks to the environment and human health.''

Still, Bogota is under heavy pressure from U.S. drug czar Barry McCaffrey's
office, the State Department and elsewhere, said a source familiar with the
project.

Colombia wants to find a strain of the fungus already in the country, rather
than risk introducing one from outside. This means that tests must start
from the beginning and sets the program back two to three years, Rosenquist
said.

In the United States, Florida has considered using Fusarium to kill
marijuana plants but that program appears to have been put on a back burner
because of environmentalists' objections.

David Struhs, the state's secretary of environmental protection, said in an
April 6, 1999, memo that he was concerned that Fusarium applied to kill drug
plants could mutate into something more dangerous.

``Mutagenicity is by far the most disturbing factor in attempting to use a
Fusarium species as a bioherbicide. It is difficult if not impossible to
control the spread of Fusarium species. The mutated fungi can cause disease
in a large number of crops, including tomatoes, peppers, flowers, corn and
vines,'' he wrote.

But Jim McDonough, director of the state Office of Drug Control Policy, said
that Florida officials were ``watching to see where the research goes'' in
terms of efficacy and safety.

``Personally it appears to me that the research is showing promise,'' he
told Reuters.

Some of the debate over whether to use Fusarium centers on what danger, if
any, the fungus poses to people.

Agriculture Department spokeswoman Sandy Miller-Hays said that the
coca-killing strain of Fusarium oxysporum does not produce mycotoxins that
could hurt farm families.

However, even without the mycotoxins, it is not clear that it is safe for
humans to be around large amounts of the fungus, said Dr. Michael Rinaldi, a
clinical mycologist who directs a fungus testing laboratory at the
University of Texas at San Antonio.

People who are severely immunosuppressed because of AIDS or cancer
treatments, for example, are vulnerable to Fusarium infections, and a minor
eye injury may lead to blindness if Fusarium is involved, said Rinaldi, who
estimates he has seen at least 100 Fusarium oxysporum infections over 10
years.

Ramon Sandin, director of microbiology and virology at the H. Lee Moffitt
Cancer Center in Tampa, Florida, said he had treated cancer patients with
Fusarium infections, and had been frustrated to find anti-fungal treatments
often did not work.

``We're not very happy when somebody comes down with a Fusarium infection.
We know the potential for demise,'' he said. ''We've lost several in the
past couple of years.''

Still, a U.S. official was derisive about the notion that the fungus could
hurt people, likening concerns about it to warning labels in microwaves
telling people not to use the ovens to warm pets.

``There are a number of people in the U.S. Congress who are enthusiastic
about this,'' the official said.

In addition to concerns about its safety, Rosenquist seemed unconvinced that
Fusarium would kill enough coca to be worth pursuing. Overall, he said, just
20 percent of released biogens do what they are supposed to.

In Peru's coca-growing Upper Huallaga Valley, the fungus is endemic and has
caused real economic losses to farmers. But while the Upper Huallaga Valley
is tropical mountains, coca in Colombia is grown on drier savanna so it is
not clear that the fungus would survive, he said.

Currently, crop-dusting planes spray Roundup (glyphosate) on coca to kill
the plants. But the aircraft must fly so low that they are vulnerable to
ground fire from coca-growers or rebels. Pilots would be safer spreading the
fungus.

``One of the methods of applying this fungus is using an airplane to eject
seeds infected with the fungus,'' the U.S. official said. ``If it could be
worked out, it would enable airplanes to fly higher than when applying
liquid herbicide.''
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MAP posted-by: Don Beck