Seeds of Concern -


Dec 3, 2012 (5 years and 7 months ago)


Title: Seeds of Concern. By: Brown, Kathryn, Scientific American Special Edition, 15512991, Dec2006 Special
Edition, Vol. 16, Issue 4


Canadian Reference Centre


of Concern

Section: In the BODY



crops an environmental dream come true or a disaster in the making? Scientists are
Booking for answers

How is your


diet going? If you ate cereal, drank soda, munched baked snacks or used
cooking oil this week, you very likely ate som
e engineered protein
now a staple of American fare.

During the past decade the amount of farmland devoted to


(GM) crops has increased more
than 50
fold, to an estimated 222 million acres worldwide in 2005, according to the Internation
al Service for the
Acquisition of Agri
Biotech Applications (ISAAA). The U.S. grows more than half this biotech harvest,
followed by 20 additional countries. Today's top crops: soybeans, corn, cotton, and canola

to tolerate
specific herbicides or
resist certain insects. Tomorrow new GM crops might withstand drought, resist viruses,
grow bigger, yield pharmaceuticals and do other things nature never imagined.

But it is not all sunshine and sweet profit for GM farming. Controversy
and confusion
r the technology
remains. "We haven't had the asparagus that ate Cleveland," says geneticist Norman Ellstrand, director of the
Biotechnology Impacts Center at the University of California, Riverside. "But there's been at least one notable
event of engineer
ed crop genes escaping from farms or field trials every year
and that doesn't give us comfort."

And GM crops suffer other growing pains. Their measurable benefit
in reduced pesticide use or increased
varies considerably, depending on the technology, crop and region. Moreover, preliminary research
indicates that at least one kind of GM cotton
is losing ground against pests. Finally, public debate over GM
foods continues, pitting state and local legislatures
and sometimes entire countries
against each other. As Jane
Rissler, deputy director of the food and environment program at the Union of C
oncerned Scientists, puts it:
"From where I sit,


crops are not a slam dunk."

A Modified Farmscape

IT ALL BEGAN With business. Although relatively small compared with other agricultural product markets,
the commercial

market in the U.S. (about $5.7 billion) and worldwide (about $25 billion)

is rapidly
growing, particularly for major field crops, according to the U.S. Department of Agriculture. Fewer than half a
dozen companies dominate the domestic

market, and as biotechnology emerged, they saw an opportunity

modify crop

with one or more desirable traits. Many farmers were willing to pay for

with these traits.

Today most GM crops contain genes enabling them to either resist insect pests or tolerate weed
herbicides (see box on page 44). The herbi
tolerant types contain genes enabling them to survive when
exposed to broad
spectrum weed killers such as glyphosate (sold as Roundup), potentially allowing farmers to
forgo more toxic chemicals that target specific weed species. The insect
varieties of GM crops make
their own insecticide, a property meant to reduce the need for chemical sprays. To date, insect resistance has
been provided by a gene from the soil bacterium Bacillus thuringiensis (Bt). This gene directs cells to
manufacture a
crystalline protein that is toxic to certain insects
especially caterpillars and beetles that gnaw on
but does not harm other organisms.

In 2005 herbicide
tolerant varieties represented 87 percent of the U.S. soybean crop and 61 percent of the cott
crop. That same year Bt varieties represented 35 percent of the U.S. corn crop.

These crops have shown clear benefit, says Zigfridas Vaituzis, a senior scientist at the Environmental Protection
Agency. "With herbicide
tolerant crops, farmers can spray t
heir fields with relatively safe, biodegradable
chemicals," Vaituzis says. "For its part, Bt cotton has cut pesticide use on cotton crops by half. A conventional
cotton crop may take 12 applications of various pesticides each season. Halving that means les
s exposure to
those chemicals, both on the farm, in groundwater and in spray drift in the surrounding community. Those are
measurable benefits."

Early environmental fears about potential negative effects of Bt corn pollen on monarch butterflies, or of Bt
oxins on soil organisms, have not materialized in repeated studies. "We've seen no uptake of Bt toxins by other
plants or any effect on soil microbes," says Guenther Stotzky, a soil microbiologist at New York University.
"That's why I'm no longer a critic
of Bt crops."

A Risky Escape

BUT AT LEAST ONE environmental risk l
ooms: escape. Researchers have long worried that unwitting insects
or the right wind could carry GM crop pollen to weedy plant relatives, fertilizing them. The newly endowed
plants could then break ecological rank, becoming "superweeds" that push out nativ
e plants or resist pesticides.

Until recently, that fear remained fiction, as scientists engineered farm crops that mostly lack wild, weedy
relatives in the U.S. But in August 2006 ecologists at the EPA reported the first wild outbreak of a GM crop: a

In central Oregon the Scotts Miracle
Gro Company had field
tested an herbicide
tolerant variety of creeping
bentgrass, for possible use on golf courses. Surveying the nearby area, EPA scientists found wild grass with the
genetic modification at six
sites, some more than two miles away from the test plots.

Reporting in the journal Molecular Ecology, the scientists suggested that wind carried the


and pollen to the locations where new plants emerged. The USDA has launched an environmental impact
assessment of the transgenic grass to determine whether it could spread and become invasive.

The runaway grass alarms scientists, in part because they worr
y that next
generation GM crops
such as
"biopharms," or plants engineered to yield pharmaceuticals
could similarly escape. "When we start growing
antigens that could get back into the food chain, this kind of event becomes much more serious," Stotzky say

Already the USDA has come under fire for its oversight of biopharming. Four environmental groups have
successfully sued the agency over biopharm field trials in Hawaii, in which corn and sugar cane plants were

to make human hormones and vaccine

ingredients to fight HIV and hepatitis B. In August a U.S.
District Court judge in Hawaii ruled that the USDA broke national environmental laws by allowing the open
field trials without first considering their environmental impact, particularly on end
angered species. In response,
the USDA has overhauled its permit process.

Beyond the field, experimental GM crops have repeatedly found their way into the food supply
twice during
the summer of 2006 alone. First, Riceland Foods, the country's largest mark
eter of rice, discovered trace
amounts of an unapproved herbicide
tolerant rice strain in its commercial rice supplies, which are grown across
a wide region of the southern U.S. In response, the European Union placed strict testing requirements on U.S.
orts, sending U.S. rice prices tumbling and provoking a class
action lawsuit by farmers alleging that Bayer
which had bred the rice
was negligent in preventing GM

from contaminating the nation's


Also last summer, the enviro
nmental groups Greenpeace and Friends of the Earth reported that their tests of
processed rice foods in London had turned up five samples of rice products imported from China, such as
vermicelli and rice sticks, containing an unapproved insect
resistant ri
ce variety. The European Commission
urged member states to step up controls of GM foods, which are not approved for consumption in Europe.

But that will be difficult to do, Ellstrand says. In an ongoing $1.5
million study funded by the National Science
ndation, he leads a team of biologists and social scientists collaborating to analyze the unintended spread of
engineered plant genes. "One serious problem is the frequent disconnect between policymakers,

salespeople, regulators and farmers about how
to grow and control GM crops," Ellstrand explains. As

food cross borders, he adds, that coordination dissolves further.

A Long Lens

WHEN IT COMES TO basic biology, even GM crop proponents worry that gains made by

plants are
only temporary. After all, evolution does not stop for technology. Insects,

for instance, may evolve strategies for
overcoming Bt technology and eventually consume the transgenic plants with no effect.

Or nature may take a different tack, as suggested by the first long
term economic impact study of Bt cotton in
China. That study,

presented by Cornell University researchers at the July 2006 meeting of the American
Agricultural Economics Association, found that farmers planting Bt cotton
designed to defy the leaf
initially prospered, cutting pesticide use by 70 perc
ent. By year seven of Bt cotton farming,
however, secondary insects such as mirids crept in, replacing the bollworm as the star scourge
and forcing
farmers to return to typical spraying levels, even as they paid for Bt
, which costs two to three times

than conventional

That does not surprise Alison G. Power, an ecology professor at Cornell. "When we breed traditional plants that
are resistant to some particular pest, the next most important pest moves in," Power explains. "We see this all
e time with plant viruses."

Rebecca Goldburg, a senior scientist at Environmental Defense, predicts that farmers will eventually lose Bt as
an effective control against insects and will then move on to another chemical control. "Many of us view this
t generation of biotech crops as a kind of diversion, rather than a substantive gain, for agriculture,"
Goldburg says.

Like scientists, politicians are at odds over GM crops. During the 2005 legislative session, 117 pieces of
legislation related to agricul
tural biotechnology were introduced in 33 states and in the District of Columbia.
Many state legislatures attempted to disallow local and county efforts to ban or limit GM

and crops. Of
the 23 state bills that passed during 2005, two thirds supported

GM technology, according to the Pew Initiative
on Food and Biotechnology.

More than anything, the public is just plain confused about GM crops, as reported in a survey released in 2005
by the Food Policy Institute at Rutgers University. In the survey of 1
,200 U.S. residents, about half said they
were unsure or could not take a position on GM foods. Roughly a fourth of them approved of GM technology,
but almost as many disapproved. Lead author William Hallman, a Rutgers psychologist, concluded that people
seem to be willing to believe just about anything they hear about GM foods." The study suggests that fewer
than half of Americans realize that supermarkets regularly sell GM foods.

Like them or not, GM crops are poised to grow
and not just in the U.S. In
2005, according to the ISAAA, 38
percent of the land planted in GM crops was in developing countries, which desperately need plant varieties that
tolerate drought and improve yield, among other traits. In 2006 Iran produced its first full
scale commercial

supply of Bt rice. China is expected to follow. "Yes, this technology will have to be
, due to
resistance factors, the appearance of new pests and other challenges," Vaituzis says. "But


crops are here to stay."

Three Worries

1 Superweeds will arise
as genes that give crops the
ability to kill insect pests or two withstand herbicides find
their way into weeds.

What the research says:

Researchers recently found accidental release of GM grass genes into wild grasses n Oregon. Such incidents
could pose serious problems both in the U.S. and in regions where GM crops have weedy relatives.


GM crops will fail
because insect pests will evolve tolerance to, or somehow overcome, built
in insecticides.

What the research says:

Studies have not demonstrated insect tolerance, but a preliminary survey of farmers in China suggests that
secondary pests unaffected by Bt gene modification are damaging Bt cott
on crops.

3 Innocent creatures will be hurt
by insecticides built into many GM crops.

What the research says:

Based on field and lab tests, the Environmental Protection Agency has determined that current GM crops
engineered with insect resistance or herbicide tolerance do not pose unreasonable risks to the envir


The year 2005 marked

the 10th anniversary of the commercialization of


(GM) crops. That
year, according to Clive James of the International Service for the Acquisition of Agri
Biotech Applications
(ISAAA), 8.5 million farmers across 21 countries planted
such crops. In total, ISAAA reports, 475 million
hectares (more than one billion acres) of GM crops have been planted. In 2005 such crops covered 90 million
hectares (222 million acres). More than half of the biotech harvest is grown in the U.S. More than
a third is
grown in developing nations.

Countries Producing GM Crops in 2005

1. U.S. 55%


3. BRAZIL 10%

4. CANADA 6%

5. CHINA 4%



6. Paraguay 16. Iran

7. India 17. Honduras

8. South Africa 18. Portugal

9. Uruguay 19. Germany

10. Australia 20. France

11. Mexico 21. Czech Republic

12. Romania

13. Philippines

14. Spain

15. Colombia

of Total GM Area in 2005

BY TYPE. . .


CORN 24%






BOTH 11%

Farmers cultivated other GM crops as well, but these essentially

dropped off the data screen when James
rounded his figures to the nearest 100,000 hectares. Among them were potatoes, squash, papayas, melons,
tomatoes and plants engineered for such traits as virus resistance, delayed spoilage and improved nutrition.


By Kathryn Brown

KATHRYN BROWN is a science writer based in Alexandria, Va. She frequently writes about botany, ecology
and earth science for magazines such as Scientific American and Science. Brown is a member of the board of
the D.C. Science Writer
s Association.


Seeds of Concern

Name: _____________________________


What do the top genetically modified crops, soybeans, corn, and canola, tolerate through modification?


How do the insect
resistant varieties of GM crops
reduce the need for chemical sprays?


In 2005, herbicide
tolerant soybean crops made up what percent of US soybean crops?


What is the concern about “superweeds”?


What was the first wild outbreak of a GM crop?


Why does the “runaway” grass alarm


What event sent U.S. rice prices tumbling?


Are GM foods approved for consumption in Europe?


What forced cotton farmers to return to typical spraying levels, even as they paid for Bt

seed, which costs two to
three times more than conventional seed?


What are the three major worries highlighted in this article?


Who are the top five countries producing GM crops in 2005?


What are the top four crops as a percent of the total GM ar
ea in 2005?


What are top 3 GM traits?