The spread of transgenic corn, soybeans and cotton

As a follow-up to Tom Philpott’s post about genetically modified crops (also known as transgenic or genetically engineered crops), I thought I’d post some data on transgenic crop adoption in the United States. Because products made from transgenic crops are never labeled, it is probably not well known that over 70 percent of the corn acreage, around 90 percent of the soybean acreage and almost 90 percent of the cotton acreage is planted with transgenic varieties. These statistics and the figure below are drawn from a report from the USDA called Adoption of Genetically Engineered Crops in the U.S.

In the figure below, the acronym HT stands for "herbicide tolerant" (the plant is impervious to a specific class of herbicide, like Monsanto’s Roundup) and the term Bt indicates that the plant carries genes from the soil bacterium Bacillus thuringiensis (which make the plant toxic to certain insects). The genes of some plants are modified to contain herbicide tolerance and Bt genes; these are called "stacked gene" varieties. Note that when the USDA calculated the quantity of HT or Bt acreage, they included the stacked gene varieties in both categories (that is why the sum of HT cotton and Bt cotton is greater than 100 percent). Fortunately, the Excel spreadsheet included with the report has a section with the percentage of acres planted with any type of transgenic crop — in 2007 it was 73 percent of corn acres, 87 percent of cotton acres, and 91 percent of soybean acres.

Graph of GMO crop adoption between 1996 and 2007 from ERS/USDA



Here are more comprehensive definitions of Bt and HT from the USDA Glossary on Genetically Engineered Crops:

Bt crops are genetically engineered to carry the gene from the soil bacterium Bacillus thuringiensis. The bacteria produces a protein that is toxic when ingested by certain Lepidopteran insects. Crops containing the Bt gene are able to produce this toxin, thereby providing protection throughout the entire plant.

Herbicide-tolerant (HT) crops were developed to survive certain herbicides that previously would have destroyed the crop along with the targeted weeds, and allow farmers to use them as postemergent herbicides, providing an effective weed control. The most common herbicide-tolerant crops (cotton, corn, soybeans, and canola) are Roundup Ready (RR) crops resistant to glyphosate, a herbicide effective on many species of grasses, broadleaf weeds, and sedges. Other genetically modified herbicide-tolerant crops include Liberty Link (LL) corn resistant to glufosinate-ammonium, and BXN cotton resistant to bromoxynil.




9 Responsesto “The spread of transgenic corn, soybeans and cotton”

  1. Bonnie P. says:

    Jeffrey M. Smith, in the talk that Tom covered, mentioned several studies indicating that eating Bt crops resulted in altered intestinal bacteria, and that many livestock had died or sickened as a result of eating Bt cotton stalks. And while Monsanto touts how less herbicides will need to be used thanks to HT crops, Smith showed USDA graphs indicating that they have led to exponentially more chemical usage.

  2. Jen says:

    It’s very disturbing to realize that conventionally grown crops are **so** heavily engineered.

    Thanks for providing actual numbers and percentages– Before I saw this I abstractly knew that many conventionally grown crops, corn & soy especially, were genetically engineered in some way, but I didn’t realize JUST HOW MUCH!! 91% of soy is a shocking number

  3. wachai says:

    I am wondering if so many people would be interested in crops that don’t offer them any benefit. The fact that GM crops are grown widely in the U.S. and elsewhere means there’s something good in them.

    I have also heard and read Jeffrey Smith’s writings on GM crops: they’re all false. Regarding cattle dying after eating Bt cotton stalks, this has been disproved scientifically. Consider visiting FBAE Blog, which is authored by a renowned scientist in India.

  4. Judi says:

    Quote: “The fact that GM crops are grown widely in the U.S. and elsewhere means there’s something good in them.”

    Um, no. It merely means that there is money in them. Money and good are not the same thing.

  5. Michelle says:

    Whether it’s good or bad, consumers should know what they are eating. Why is it up to the non-GMO brands to label themselves? It strikes me that if GMOs were ‘good’, marketers would be shouting the benefits from rooftops instead of keeping it quiet.

  6. Most of the currently grown GE crops have traits that the farmers are interested in. Cotton, for example, normally requires a ton of pesticides to grow, and Bt cotton reduces that amount.

    I agree that consumers should be able to know what they’re eating, however, a “GMO” label doesn’t tell you anything about what the trait is, it only tells you how the trait was derived.

    There are a lot of myths going around about genetically engineered crops, and there are few people trying to explain the science behind them to the general public. On the same token, the people most active in fighting the use of transgenic crops aren’t usually very interested in checking their facts. Hence the sheep example, et al.

  7. Responding to Inoculated Mind: In an ideal world, GMO labels would say whether the transgenic plants had their DNA poked and prodded to allow heavy sprays of pesticide or to reduce the need for pesticide, or whatever their trait happened to be (and whether the plant is covered by a patent). But there is no need to wait until the perfect labeling system is available to provide information to consumers. It doesn’t matter to me (and probably many others) whether the DNA is modified for pesticide resistance or to contain bits of the Bt bacterium’s DNA. Either way, the DNA has been directly tampered with. So let’s start with a simple “contains genetically modified corn/soybeans/cottonseed oil” and work on making it more complicated as time goes on.

  8. Re: Mental Masala,

    In reality, the DNA of crop plants has been poked and prodded through selective breeding, mutagenesis, the fusion of multiple species into tetraploid and hexaploid varieties. In addition, new genes are brought into food (and other) crops through outcrosses

    There’s a give and take to the different traits currently being grown. You mention “heavy sprays of pesticide,” but don’t recognize that it is allowing farmers to abandon far worse herbicides (such as Atrazine). Shouldn’t we therefore label all foods that have had Atrazine sprayed on them? It might not be a bad idea actually. In addition, you should therefore also label all the organic crops that are sprayed with toxic rotenone, fish-killing copper sulfate, etc. How will this help the consumer?

    Indeed, some crops have been bred to have herbicide tolerance through conventional breeding – how come no one’s pushing to label those?

    The “contains GMO” label seems to be more of a political measure, aimed not at “knowing what’s in our food,” but instead trying to put a market pressure on the use of this technology. It only serves those that are against the technology in its entirety.

    It doesn’t matter to me (and probably many others) whether the DNA is modified for pesticide resistance or to contain bits of the Bt bacterium’s DNA. Either way, the DNA has been directly tampered with.
    And in that statement you confirm that.

    An informative labeling scheme is possible, but the people pushing for labeling schemes aren’t interested in an informative label.

    My two cents on the labeling issue is that any mandatory product labeling should be done in the interest of public good, not the predispositions of a few.

    There’s really a lot more than herbicide tolerance and Bt pest resistance genes going on with GE crops. You have viral resistance in squashes, (which prevents the need to spray pesticides to control viral vectors, i.e. Insects) and there are the newly developed (and therefore not commercialized) nutritionally enhanced tomatoes and carrots. An Australian company made the world’s first ever blue roses and purple carnations, and a Japanese company removed more than half the caffeine from a coffee bean variety through RNAi. Even some organic farmers (In Marin County, CA!) want to grow them. Genetic Engineering is really not the Frankensteinian process extremists would like you to believe.

  9. That’s strange, in my comment above, the blockquote-closing tag didn’t work. From “And in that statement…” onward are my words.