Controversy about GMO crops never seems to go away

We’re all familiar with the term GMO, and many have already made up their minds about these crops. Unfortunately, most people don’t really know how they were developed or how they are different from any other commodity.

That doesn’t stop opinions from forming. To be honest, genetically modifying food and other crops has been around since farming began. Farmers have always selectively bred crops and livestock.

Most plants considered GMO are ones that have been modified by a process other than simple selection and breeding. The results are organisms that contain genetic material from different species. We call these transgenic organisms.

Decades ago, scientists found that a bacteria species called Bacillus thuringiensis (Bt) produced a chemical that was toxic to most caterpillars. It was and is still used as a pesticide to kill these plant pests.

In the mid-1990s, the gene from this bacterium was inserted into corn DNA and the result was a plant that was resistant to European corn borer and other related pests. The corn plants were able to produce the same chemical that the Bt bacteria did. They needed no additional pesticide to control the caterpillars. Yield and quality increased.

Additionally, no traces of Bt related chemicals were present in any part of the plant other than the foliage. This meant fewer pesticides were necessary to produce corn, and if only the grain were used, no chemical would be consumed.

About the same time, scientists stumbled upon another bacterium that contained a gene resistant to the effects of the chemical glyphosate (Round-up). This gene was incorporated into soybean plants and Round-up Ready Soybeans were born. The soybean plants can break down the pesticide and not the other way around.

Glyphosate is a chemical that is non-selective. That means it kills all plants hit by the spray. This herbicide has many desirable traits. It has low toxicity to mammals, it doesn’t persist in the environment for very long, and it doesn’t get absorbed by plant roots.

Reducing the amounts of pesticide necessary to produce crops is a major goal of GMO research. Furthermore, EPA regulates all transgenic crops, so they undergo substantial testing before new ones can be released. Developing chemicals that decompose quickly makes producing crops safer, too.

The upside to GMO technology is high. However, there are potential environmental problems that could result. Back in 1989 scientists took a gene from a Chinook salmon and an ocean pout, which has the ability to eat and metabolize food at extremely low temperatures. They inserted this into an Atlantic salmon.  Atlantic and Chinook salmon are close relatives but won’t cross naturally. Ocean pouts are totally unrelated. The result was a growth rate that was close to four times faster.

This sounds great, but what if that cross was introduced into wild populations somehow? Other species might be put at a disadvantage and natural balance of ecosystems could be disrupted. I realize wild Atlantic salmon populations aren’t what they once were, but this could be like the dilemma of the resident Canada geese.

We also could generate superweeds if any cultivated GMO species crossed with wild ones. For example, if GMO sunflowers were developed and they crossed with wild types, it could be a problem.

GMO technology has great potential for solving world hunger, but scientific ethical standards are critical. Short-term thirst for money can destroy great science.


Ted Manzer teaches agriculture at Northeastern High School.

About tedmanzer

I grew up in Old Town Maine and got a B.S. at the University of Maine in Plant Sciences/ minor in Botany. From there I moved to West Virginia and earned a M.S. in Agronomy at WVU. I also met my wife there. She grew up in rural WV as the daughter of tenant farmers who raised cattle and hogs. Their lifestyle at times was one of subsistence and I learned a lot from them. I've always been a foraging buff, but combining my formal botanical knowledge with their practical 'Foxfire-type' background opened up my eyes a little more. I recently retired from teaching high school agriculture after 25 years teaching with my wife. Until recently I wrote a weekly nature/foraging column for the local paper ( I also have written several Christian nature/adventure novels that can be purchased on Amazon in Kindle format. One is a five book family saga I call the 'Forgotten Virtues' series. In the first book, Never Alone (presently out of print), a young boy comes of age after his father dies in a plane crash, and he has to make it alone. The second book, Strange Courage, takes Carl from his High School graduation to his recovery from a nasty divorce. The third book, Second Chances, takes Carl from his ex-wife's death and the custody of his son to his heroic death at age 59. The fourth book, Promises Kept, depicts how his grandchildren react and adjust to his death (this one is not yet published). In the final book, Grandfather's Way, his youngest and most timid granddaughter emerges from the shadow of her overachieving family and accomplishes more in four months than most do in a lifetime. I use many foraging references with a lot of the plants I profile in these articles in those books. I also wrote a romance novel titled Virginia. It is available on Amazon and is a different type of romance from a man's perspective.
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2 Responses to Controversy about GMO crops never seems to go away

  1. abby millager says:

    If glyphosphate is harmless to mammals, why is it banned in Europe and now the subject of a slew of lawsuits against Monsanto, related to cancer? It was classified by the WHO as “probably carcinogenic to humans” in 2015.
    I agree that Bt corn is probably ok to eat.
    But there is also Round-up ready corn, as well as Round-up ready soy.
    The problem with roundup ready GMO edible plants is not the genetics of the plant (in my opinion) but rather the fact that now that crop may be indiscriminately treated with massive quantities of roundup and I’m worried about eating the residue.
    So I avoid GMO corn and soy products–not because of the mutations but because of the herbicides.

    All that said, I really enjoy the concept of your blog (which I just discovered) and hope to read more of it!

    • tedmanzer says:

      It’s not harmless. It does have a relatively low toxicity. There are many more highly toxic pesticides commonly used. The biggest problem with glyphosate is that it was developed by Monsanto, and that company is considered the devil, deserved or not.

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