GE: Herbicide Resistance, NO Increased Yields & Inconclusive Environmental Effects
Recently, we discussed GE for the trait of pest resistance with the case example of Bt toxin. Now, we are going to explore crops that are GE with herbicide resistance traits. These GMOs are designed to survive exposure to herbicides that would normally be fatal.
The goal of GE herbicide resistant crops is to increase yield via enhanced weed control. [1] The goal is to kill all plants except the GE crop, and to prevent casualties of the intentional GE crop thanks to its forced-in herbicide resistance.
One would hope that herbicide use may decrease as a result of GE crops. Not so. While herbicide levels initially decreased with the adoption of the GE crops, these decreases have not been sustained. [2] In other words, farmers still depend on copious amounts of chemical weed killers.
Moreover, the way corporate scientists report herbicide use is sneaky: they simply report kilograms per hectare per year without factoring in the differences in toxicity amongst the various chemicals used. It sounds like lying by omission to me by excluding the practical MEANING of study results.
According to the #GECropStudy, “the herbicide-resistant trait selects for weed resistance only if the corresponding herbicide is applied to the field.” [3] This sounds admittedly cool, but I would like to see further clarification. My understanding is that if farmers were to decide not to use weed-killing chemicals then the GE plant would grow normally without expression of the herbicide resistant trait. Not sure what the point is here. Perhaps to make GE look precise?
Similar to insects able to resist Bt toxin, weeds become able to resist herbicides over the course of repeated exposure. Nature is smart! The weeds that survive the herbicide application proliferate, stronger and more resilient than ever. As a result, farmers must utilize diverse weed management strategies, like “cropping systems and regions where weeds have not yet been exposed to continuous glyphosate applications.” [4] The report concluded that more research is necessary. Read: they don’t know how to outsmart nature on this one.
GE crops are not really increasing yields in US agriculture. Oops, I thought that was the point.
When considering USDA data of changes in yield in maize, soybeans, and cotton fields before, during, and after switching from conventional breeding to GE crops, scientists found “no significant change in the rate at which crop yields increase.” [5] This is in contrast to experimental data—most likely done by biotech corporations themselves—that showed yield increases related to the introduction of GE crops.
This begs the question: why are we using GE crops if they don’t accomplish the desired end: increased yields compared to conventional breeding?
Money? Power? I don’t know. The possibilities aren’t super awe-inspiring.
Biodiversity
So far researchers have not found a decrease in diversity among crop varieties, weeds, and insects. [6] Although they admit it is possible to occur in the future.
Conclusions about the environmental effects of GE Crops
The report concluded a lack of conclusive evidence that GE crops are CAUSING environmental problems. However, the report added that “the complex nature of assessing long-term environmental changes often made it difficult to reach definitive conclusions.” [7]
I sense more convoluted bullshit; how about you? In other words, they don’t know. Either the data really aren’t there to determine the effect of GE crops on the environment, OR corporate interests are blocking scientists from reporting data that do show a causal relationship between GE crops and environmental harm.
The researchers called for lots more research. [8] In the meantime, GE crops are still being commercially grown on millions of hectares of land in the US, showing up in millions of grocery stores worldwide, and ending up in the food eaten by millions of Americans. Shouldn’t the research have been done before such widespread adoption of GE? I would think yes.
References:
[1-8] National Academies of Sciences, Engineering, and Medicine. 2016. Genetically Engineered Crops: Experiences and Prospects. Washington, DC: The National Academies Press. doi: 10.17226/23395.
Disclaimer: These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease.