The New York Times recently published the article "Doubts about the Promised Bounty of Genetically Modified Crops" which addresses the controversy surrounding the benefits of GM crops. Author Danny Hakim claims his “extensive examination” of the data provides evidence that genetically modified (GM) or engineered (GE) crops have not lived up to their most basic promises that they: 1) increased crop yields and 2) reduced overall chemical pesticide usage.
Contributing writers Susan Leaman, Diane Wetherington, and Samantha Duda have extensive experience and knowledge in the food industry. Susan works with companies and associations to develop solutions that address produce-related food safety issues; Diane is CEO of iDecisionSciences, LLC, a provider of specialty crop consulting services, and iFoodDS, Inc., a software solutions provider for the food industry. Sam joined iDecisionSciences, LLC as a research and analytics associate.
We were curious what experts in this field thought about the research presented by Hakim to support his claims, and found that a number of respected scientists swiftly responded.
Many who wrote letters to the editor or posted their opinions online called the author’s main assertion that GM crops were designed primarily to increase crop yields and reduce pesticide use as “a false premise”.
Dr. Steve Novella in his blog NeuroLogica writes, GM technology “is not inherently tied in any way” to any one application. Rather, he describes the promise of GM technology as providing “a tool for agricultural scientists to make more rapid and more specific changes to crop cultivars” using methods deemed “safe with no demonstrable inherent risks beyond any other method of crop development”.
In an open letter to the NY Times Public Editor (firstname.lastname@example.org), a group of scientists assert GM crops were “designed to manage and mitigate some of the causes of crop loss, especially pre-harvest losses due to insect pests or weeds.”
To many scientist critics, Danny Hakim missed the point of GM crops from the start.
Let’s take a closer look at the claim “GM crops promise, but do not deliver high crop yields.” To support this claim, Mr. Hakim uses rapeseed (canola) yield data from the Food and Agricultural Organization (FAO) of the United Nations to compare GM rapeseed yields in Canada to non-GM rapeseed yields in Western Europe. The data that is presented by Mr. Hakim does show that non-GM rapeseed yields in Western Europe are higher than Canadian GM rapeseed yields even as yields are increasing at a similar rate for both production areas.
Comparing yields in developed countries is inappropriate with since GM crops were not intended to further increase already high yields in developed countries like the United States and Canada.
GM crops are widely used in developed countries today primarily for two traits:
- Insect resistance (IR; resistance to certain types of pests)
- Herbicide tolerance (HT; imparts tolerance to an herbicide like glyphosate).
Graham Brookes, an agricultural economist with PG Economics UK, notes it is not surprising that average yields are higher in Western Europe than in Canada due to the seasonality of this crop. Canadian rapeseed is mainly a spring crop whereas in Europe, it is a winter crop, and winter crops generally yield better than spring crops.
Dr. Matin Qaim, a professor of agricultural economics at the Universities of Bonn and Kiel, further points out that Canadian farmers use GM rapeseed to reduce herbicide cost, labor, and fuel use due to the herbicide tolerance trait, and not to increase yields.
Although prior to the implementation of GM technology, many North American farmers were already using effective pest and weed control methods. Dr. Val Giddings, a senior fellow at the Information Technology and Innovation Foundation in Washington, D.C. explains that seeds provide superior pest control to non-GM seeds. GM seeds are designed to select and attack a specific pest rather than a broad-based effect typically delivered by common pesticides.
If you assume (as Danny Hakim proposes) that one of the main reasons developed countries like the U.S. and Canada use GM crops is to increase yields, it is still inappropriate to evaluate yields solely based on genetic modification. According to Graham Brookes, a seed’s genetic capability and “its ability to withstand yield-reducing effects of pests, diseases and weeds” are only two of many factors that affect yield. When considering the complex nature of the outdoor growing environment, there are numerous factors affecting yield including weather, soil quality, farming practices, inputs (e.g., fertilizers, pesticides, and seeds), farmers’ knowledge and skills, and the effectiveness of existing technology to control pests, diseases, and weeds among others.
Dr. Qaim published an analysis of 147 independent studies showing GM technology has indeed increased crop yields worldwide by 22% with developing countries experiencing higher increases in yields than developed countries.
GM crops and reduced pesticide use
Danny Hakim reviews herbicide, fungicide, and insecticide use data from the Union of Industries of Plant Protection in France, the U.S. Geological Survey, and the U.S. Department of Agriculture to support his claim that GM technology broke its promise to reduce pesticide use. He states “the United States has fallen behind Europe’s biggest producer, France, in reducing the overall use of pesticides, which includes both herbicides and insecticides”.
The data in the chart he used as evidence to support this claim had different units of measurement (thousand metric tons for France, compared to million pounds in the U.S.). Additionally, the amount of pesticides is not standardized per unit area. As Dr. Andrew Kniss, an associate professor in weed biology and ecology at the University of Wyoming points out, this is acutely important since the U.S. has over 9 times the amount of arable land that France has. After converting the chart to the same units and standardizing by farmland, it is clear that France (though reducing their pesticide use) still uses far more pesticides than the U.S. — in particular fungicides and insecticides. As Dr. Kniss explains in his analysis of Mr. Hakim’s article,
“A relatively tiny proportion of these differences are likely due to GMOs; pesticide use depends on climate, pest species, crop species, economics, availability, tillage practices, crop rotations, and countless other factors. And almost all of these factors differ between France and the U.S. So this comparison between France and the U.S., especially at such a coarse scale, is mostly meaningless, especially with respect to the GMO question.”
Dr. Andrew Kniss, Associate Professor in Weed Biology and Ecology, University of Wyoming
Dr. Kniss also posted charts showing herbicide use for other European countries as evidence pesticide use has actually increased, with France being one of a few exceptions.
In the U.S., switching to an herbicide-tolerant crop allows more toxic herbicides to be replaced by a less toxic one such as glyphosate, the active ingredient in Roundup®…
Dr. Kniss reports, “Glyphosate has lower chronic toxicity than 90% of all herbicides used in the U.S. in the last 25 years.” So as U.S. farmers increased their glyphosate use, this usage has replaced more toxic herbicides that posed known risks to the environment and human health. Assessing herbicide usage alone misses the overriding fact that harmful effects on the environment and human health from more toxic herbicide use have dramatically decreased due to the implementation of GM crops. A 2016 peer-reviewed study took into account a pesticide’s environmental impact in its analysis and found that U.S. farmers growing GM maize and soybean crops used as much soybean herbicide as non-GM crop adopters, 9.8% fewer maize herbicides, and 10.4% fewer maize insecticides (Perry, 2016).
Hakim used a faulty comparison and an inaccurate chart to support his claim that pesticide use, as measured by weight, has not been reduced— but is using weight to evaluate pesticide use even useful? The National Academy of Sciences (NAS) doesn’t think so.
In their report, on The Impact of Genetically Engineered Crops on Farm Sustainability in the U.S. released early this year, the NAS recommended “researchers should be discouraged from publishing data that simply compares total kilograms of herbicide used per hectare per year because such data can mislead readers. Simple determination of whether total kilograms of herbicide used per hectare per year have gone up or down is not useful for assessing changes in human or environmental risks.”
Otherwise, using the measurement of weight for pesticide does not tell us anything about its toxicity. While Hakim cites pesticides such as sarin in his discussion of pesticide toxicity, he does little to explain the toxicity differences between pesticides commercially available and used in agriculture today and pesticides developed decades ago and nefariously used as weapons in wars.
To say that all pesticides are toxic is true but misses the point that they all differ significantly in the magnitude of toxicity and the organisms they affect.
In her response to the NY Times article, Dr. Nina Fedoroff who is Emeritus Professor of Biology at Pennsylvania State University explains how herbicides used today are developed to be toxic to plants by interfering with biochemical pathways and processes humans do not have.
For readers who are researching GM crops whether driven by interest or concern, it is imperative to investigate reports that appear to contradict other published peer-reviewed scientific studies. The formal and informal peer-review process that comes with publishing in the scientific literature provides an added level of confidence you are getting information that is not manipulated to support a particular narrative.
Rarely does technology create a magic bullet, and genetic engineering is no exception. However, the article goes beyond discussing any downsides to GM technology by misusing data in an attempt to dismiss the value of GM technology altogether. This article ignores the fact that farmers are business people who rely on their land and crops to stay in business. They test different varieties of seeds and analyze benefits and trade-offs to see what works best for them. So if the cost of GM crops outweighs the benefits, farmers will be the first to react by not planting GM seeds.
The Bottom Line
This article ignores the fact that farmers are business people who rely on their land and crops to stay in business. They test different varieties of seeds and analyze benefits and trade-offs to see what works best for them. So if the cost of GM crops outweighs the benefits, farmers will be the first to react by not planting GM seeds.