DRUG WAR AWAITS ATTACK OF KILLER FUNGUS

BOZEMAN, Mont. -- Dr. David C. Sands holds out a clear plastic petri dish
filled with a white fuzzy fungus growing across the bottom. This substance,
he believes, is the key to ending much of the world's production of illicit
drugs.

Members of Congress also believe that Dr. Sands and other researchers may be
on to a powerful and environmentally safe method of killing not only coca
plants, but also marijuana and poppy plants. The members have asked the
government of Colombia to test a strain of Fusarium oxysporum over the next
two years. If it proves effective, the disease will be sprayed on vast
fields of coca plants there, and experts say it could wipe out much of the
coca crop within a year.

The research holds such promise that officials at Montana State University
ended it two years ago, fearing it could make the university a target of
drug cartels. But the technique had already been developed.

Others are not sure that fusarium will be effective against the the cartels.
"Efficacy is high on my list of concerns," said Eric Rosenquist, a United
States Department of Agriculture official involved with international
research programs.

"You can put a lot of energy into this and get nothing out in the end." Mr.
Rosenquist said a naturally occurring fusarium coca virus in Peru had killed
only 40 percent of the crop there.

An attack on coca plants may be only a first salvo in the attack of the
fusarium fungus. Dr. Sands and others believe that the use of fungal disease
is an ideal way to kill a broad range of undesirable plants. Research on
fusarium has been under way for years, and Dr. Sands and other scientists
say the research is about to usher in an era of effective and
environmentally safe controls that would be alternatives to chemical
herbicides and genetically modified organisms.

Biological controls, the use of a pest's enemies against it, are old:
centuries ago, the Chinese built bridges between trees so predatory ants
could find and destroy aphids. But biological control is not yet proven as a
viable alternative to chemicals. Most diseases and predatory insects, for
example, are not especially deadly; they "farm" a plant, attacking it but
not wiping it out, so they can keep consuming it.

"They live in total coexistence, like real estate agents," Dr. Sands said.
"They take a percentage. If they took too much they would be out of
business."

But some diseases are especially virulent, wiping out most or all of the
host. Phytophtora, a fungus that destroyed potatoes in 19th-century Ireland
and caused the great famine there, is one. Fusarium, Dr. Sands said, is
another of the "Attila the Hun" diseases, and there are strains of fusarium
for virtually every cultivated plant and many wild ones.

A plant pathologist, Dr. Sands came to the field of bioherbicides in his
search for a way to treat exotic plants from Asia that run rampant through
Western range land because they are unchecked by native enemies. Some
diseases found in Montana are being tested on these weeds. But a much more
effective approach, Dr. Sands said, may be to bring back the fungal diseases
that the weeds evolved with in Central Asia and elsewhere and use them as
herbicides.

He has had collaborators scouring Kazakhstan and Russia for diseases that
evolved with two especially difficult species, spotted knapweed and leafy
spurge, and some have been shipped to the United States where they remain in
a containment facility in Maryland awaiting approval to be used in testing.

In 1987, while working with weeds, Dr. Sands got a call from the department
of agriculture. Worried about a revolution in Peru, Coca-Cola had
established a coca plantation in Hawaii to assure a supply of the plant for
its soft drinks. (The stimulating components of the plant are not included
in the product.)

When the plantation was abandoned, the department used the plants to test
herbicides that might be used in the drug war. But something killed many of
the plants in a control plot that was not being sprayed. Dr. Sands
discovered that it was a strain of fusarium.

Dr. Sands cultured the fungus and spread it as granules on a three-acre
plot. It killed nearly all of the coca plants.

Fusarium is especially virulent on plants that dominate a landscape, he
said. Dutch elm disease and chestnut blight are both fungal diseases similar
to fusarium. They destroyed trees across America because those trees were
the only ones that many cities planted.

While Dr. Sands believes that importing diseases can be an effective
approach to combating exotic weeds in Montana, officials in Colombia say
they will use an indigenous fungus, a strategy Dr. Sands also advocates,
because coca is a native plant. But because politics as well as biology is
involved, the outcome in Colombia remains in question.

Conservationists generally favor substitutes for chemicals in killing weeds,
but some are not sure that de facto biological warfare is the answer. They
worry about "mission drift"; a disease may start as an effective enemy of
coca but somehow change hosts and kill important nontarget plants, like
bananas, or attack wild relatives of the coca plant and threaten
biodiversity.

Dr. Peter Stiling, a professor of biology at the University of South Florida
who has studied introduced species, says possible unintended effects have
not been sufficiently examined. "I am not prepared to come down on one side
of the fence." Dr. Stiling said. "But I think we should be careful. It's
difficult enough to find the nontarget effects of insects, and it's even
more difficult for nontarget effects of fungi and bacteria."

Such problems are often subtle at first and might not be found for a long
time, Dr. Stiling said. A study in Oregon has indicated that the use of Btk,
a bacterial pesticide for control of the western spruce budworm, may have
reduced the abundance and diversity of butterfly larvae.

"There are 500 people working on fusarium," Dr. Sands responded, "and we
don't see it changing its host species."

So far, no environmental problems have been blamed on fusarium, largely
because it has not been widely used in the United States.,

The use of fungal disease as a herbicide was studied before by the
Agricultural Research Service, but the agency determined that it wasn't
viable as a biological control primarily because it required a great deal of
the product to cover the vast areas involved.

To make fusarium economical, Dr. Sands and other researchers have discovered
they can use a native grass seed to culture the fungus. In a patented
process, they spray fusarium on the seed and drop it; when it hits the
ground the fungus multiplies. Once the fungus kills the coca plants, the
theory goes, the grass seed or whatever seed officials choose to use, takes
over for the dead plants.

What's more, the fungus lasts in the soil. "They kill and they survive the
nongrowing season perhaps for as long as five years," Dr. Sands said.

Another advantage to fungal defoliants is that while chemicals must be
sprayed on coca plants from very low altitudes during daylight, fusarium can
be dropped from thousands of feet above the fields at night.

Although the university ended the fungus research, Dr. Sands said that
others could easily follow his formula for making fungus-based
bioherbicides.

Culturing fungus is fairly simple and can be taught in a couple of weeks, he
said.

The coca producers could respond with a fungicide or disease-resistant
plants, but Dr. Sands said that could take many years.