July 5, 1999 | 4 comments

Poison Plants?

Genetically modified crops, grown over much of the U.S., remain controversial

 
e-mail print comment

Monarch
Image: World Wildlife Fund, Canada
ENDANGERED MONARCHS. Scientists say the larvae of these butterflies die when they eat milkweed leaves onto which pollen from genetically modified corn has drifted.
It looks just like a midwestern corn field is supposed to look this time of year; lush and richly green, stretching to the horizon. Maybe even a little bit better--there seems to be less pest damage to the leaves, and fewer weeds grow between the rows. The same is true for the fields of soybeans and the potatoes growing in Idaho.

Yet appearances can be deceiving. Indeed, there are quite a few people who would like to rip these super-ordinary looking plants out by their roots. These crops, being embraced by big agriculture in the U.S., carry genes that imbue them with resistance to herbicides and lace their tissues with a bacterial toxin harmless to humans but fatal to pests that may try to feed on them. For corporate farmers, the promise of such genetically modified crops seems clear--higher yields, superior quality, better nutrition and less need for spraying highly toxic and expensive pesticides.

Since the first genetically modified seeds were sold to farmers just a few years ago, the amount of acreage planted has grown exponentially. By the 1998 growing season, it was estimated that genetically altered crops planted in the U.S.--including tomatoes, squash, cotton, canola, corn, soybeans, rapeseed and potatoes--covered an area the size of Scotland. Corn alone, then in its first season after winning regulatory approval, accounted for some 15 million acres. The percentage of genetically modified seed, some experts estimate, is now approaching 40 to 60 percent of all U.S. plantings. More designer seeds are wending their way through the review and approval processes of the Department of Agriculture, the Food and Drug Administration and the Environmental Protection Agency, which regulates pesticides.

It is almost a certainty that practically everyone living in the U.S. has eaten some food that contained the produce of a gene-spliced plant. That's enough to make some people gag.


Do the risks of genetically modified crops outweigh the benefits?

Read what other readers say.


When genetic engineers began modifying bacteria to produce a new generation of drugs, such as human insulin, there was little outcry. But people seem to be far more finicky about what they put in their mouths for nutrition. As soon as plant scientists began tinkering with foodstuffs, controversy raged. Developers of modified seeds, among them Monsanto, Cargill, Novartis, Du Pont and a small horde of agbiotech startups, became the targets of demonstrations--and sometimes open warfare. Experimental plots were vandalized; protesters tried to block the loading of ships with genetically altered crops.

On the front lines of the controversy these days is Monsanto Inc. The agrochemical giant has developed a line of seeds that are resistant to its multi-billion dollar a year herbicide, Roundup, and carry a gene from a soil bacterium called Bacillus thuringiensis. The organism produces a toxin that makes plants the last repast of common insect pests.

In theory, at least, Monsanto's scheme would appear to be a boon to humanity. The gene conferring resistance to Roundup, a chemical known as glyphosate, allows farmers to spray fields with a broad-spectrum herbicide that will spare only the selected crop. And this ability in turn lets farmers optimize their use of "no-till" agriculture, a tactic that can reduce soil erosion by an estimated 70 percent.



Read Comments (4) | Post a comment 1 2 3 Next >


Share
Propeller    Digg!  Reddit delicious  Fark 
Slashdot    RT @sciam Poison Plants?Twitter Review it on NewsTrust 
sharebar end

You Might Also Like


Discuss This Article


Click here to submit your comment.

VIEW:

2,573 characters remaining
 
  Email me when someone responds to this discussion.
 

risk free issue 

Sciam - cover Email:
Name:
Address:
Address 2:
City:
State:  
spacer



World Changing Ideas



Editor's Pick


Newsletter

Basic Science Newsletter

Get weekly coverage delivered to your inbox


 Podcasts

  • 60-Second Science     RSS  · iTunes Botoxed Face Impairs Bad Feelings
    click to enable

    Download

  • 60-Second Science     RSS  · iTunes Distracted Customers' Wait Times Fly
    click to enable

    Download





ADVERTISEMENT
 
 


Also on Scientific American


© 2010 Scientific American, a division of Nature America, Inc. All Rights Reserved.
ADVERTISEMENT