Posted on 24-1-2002
Biotech
Learns From Nature
by Fred Pearce, BioMedNet News, news.bmn.com/news/
Could farmers grow more crops by planting weeds? It sounds improbable,
but
agricultural researchers in three African countries are about
to begin the
first ever detailed investigation into just this idea. The aim,
says the
Kenyan researcher behind the project, Zeyaur Khan, is to find
new ways to
fight the insect pests that menace grain crops by using selected
weeds as a
"fatal attraction - an alternative tasty food source that will
lure and
then kill them."
The project will catalogue the biodiversity of hundreds of species
of wild
grasses still growing in wasteland in Kenya, Mali and Ethiopia.
It will
chart their often complex relationships with insects - and seek
out those
that could be used as natural pesticides. Khan, who works for
the
International Centre of Insect Physiology and Ecology (ICIPE),
based in
Nairobi, figures that wild gramineae grasses, close relatives
of modern
cultivated cereals, often attract and repel the same pests.
So these
forgotten weeds make potentially ideal decoys, he says.
In collaboration with UK scientists at the Institute of Arable
Crop
Research at Rothamsted, he has already uncovered one such grass.
Napier
grass (Pennisetum purpureum), a common weed across much of Africa,
attracts
the moths of the stemborer, an insect whose larvae eat up to
a third of
maize crops in fields across the continent. Khan works from
ICIPE's
research station at Mbita Point on the shores of Lake Victoria
where he
discovered that local stemborer moths prefer napier grass to
maize.
Moreover, the weed produces a sticky glue that traps and kills
their larvae.
Farmers have been ripping up napier grass for years to clear
ground toplant
more maize. Inadvertently, this has encouraged the stemborer
to invade
their fields. But in the past four years, Khan has persuaded
thousands of
farmers in Kenya and beyond to grow napier grass round their
fields to
attract and kill the stemborer. Yields have risen by up to 30%
as a result,
he says. Now the idea is to find other similar relationships
by researching
other gramineae grasses long ignored by science. ICIPE's director,
Dutchman
Hans Herren, says the aim is both to help conserve the biodiversity
of the
fast-disappearing wild grasses and to help farmers practice
cheap,
chemicals-free pest management. "We want to know what causes
plants to
attract and repel insects," Herren told BioMedNet News. "We
know that
napier grass attracts and kills stemborers. But do other grasses
do similar
things to important crops pests? We expect to find them. Then
we can fight
the insects where they are weakest."
The $2.5 million project is being paid for by the Global Environment
Facility, based in New York.
Bacteria Aren't Corny
by Tim Todd
A dozen years ago and more than 3,000 miles from his Wisconsin
home, Eric
Triplett, according to this story, got an idea that could represent
a new
application of biotechnology to boost corn production that may
eventually
result in cornfields that don't need nitrogen fertilizer, a
large component
in corn production and a major cost factor for farmers.
The story says that Mr. Triplett, a microbial ecologist at the
University
of Wisconsin-Madison, is the leader of the first group of scientists
to
isolate and identify strains of plant bacteria that can increase
corn
yields by 5% to 10%, essentially giving U.S. farmers the potential
for an
additional 13 to 14 bushels per acre, based on the current average
U.S.
yield. The scientists have applied for a patent through the
Wisconsin
Alumni Research Foundation.
Mr. Triplett was cited as saying he started thinking about the
potential in
corn bacteria while guest lecturing at a Brazilian farm agency
in 1990.
While there, he said, Brazilian scientists showed him their
work on
sugar-cane bacteria that produce all of the nitrogen that crop
needs. The
story goes on to say that the product, however, doesn't involve
the
modification of genes -- a process seed companies have used
to create
soybeans able to withstand weed killers and corn able to resist
certain
pests but one that has also drawn the ire of some environmentalist
groups.
"There has been no genetic modification of the strains at all,"
Mr.
Triplett said of his project.
|