Controversy over GMO crops never seems to go away

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By Ted Manzer

Saturday, June 15, 2019

We’re all familiar with the term GMO, or genetically modified organism, 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 less 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 bacteria 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 the 1990s scientists took a gene from a northern flounder and inserted it into a species of salmon used for aquaculture. The result was a growth rate that was four times faster.

This sounds great, but what if that gene was introduced into wild populations somehow? Other species might be put at a disadvantage and natural balance of ecosystems could be disrupted.

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.