Traditional corn and science
No scientific basis to protect traditional corn in Mexico?
Determining whether the importation and propagation of genetically modified corn to Mexico from the United States has been a long running battle. Protectionism of the existing corn industry in Mexico could be a strong incentive to limit imports. However, Mexico has taken several legal steps to protect its traditional and heritage corn from contamination from genetically modified corn. Most recently, triggering this recent dispute, Mexican President Andres Manuel Lopez Obrador signed a decree first in 2020 that would ban the use of genetically modified corn in tortillas and food and also plan for eventual elimination of glycophosphate containing corn (the genetic modification in GE corn) in a couple of years.1 In February 2023, the decree was modified to remove the eventual elimination of GE corn from importation and use in Mexico, citing in Art. 6 of the President’s decree the need to protect indigenous corn varieties:2
Article Six.- For the purpose of contributing to food security and sovereignty and as a special measure of protection for native corn, milpa, biocultural wealth, rural communities, gastronomic heritage and the health of Mexicans, the biosecurity authorities, within their area of competence, in accordance with applicable regulations, will revoke and refrain from granting permits for the release into the environment of genetically modified corn seeds.
Likewise, the biosecurity authorities, within their area of competence, in accordance with applicable regulations and based on criteria of sufficiency in the supply of glyphosate-free corn grain, will revoke and refrain from granting authorizations for the use of genetically modified corn grain in the diet of Mexicans, until it is fully replaced on a date that may not be later than January 31, 2024, in accordance with the country's food self-sufficiency policies and with the transition period established in the first article of this Decree.
This decree raised alarms with the U.S. which is the major exporter of corn to Mexico, the world’s biggest importer of corn,3 making no distinction in genetically modified corn. A study of the costs of this ban quoted by the Congressional Research Service4 found that:
In October 2022, a study sponsored by certain Mexican and U.S. agricultural groups was released that highlighted the potential negative economic impact of a Mexican GE corn ban on USMCA countries. The study estimated a 10-year forecast showing an economic loss of $13.61 billion for the U.S. corn industry and a 19% rise for the cost of non-GE corn in Mexico.5
The U.S. demanded that Mexico explain how the GE corn ban was based on a scientific reason — the criteria for banning imports in the United States-Mexico-Canada Agreement (USMCA).6 Failing to provide a scientific basis, the U.S. proceeded to use the dispute resolution process of the treaty to appoint a panel to resolve the dispute.
In December 2024, a panel appointed for this dispute under the United States-Mexico-Canada Agreement (USMCA) recommended that the measures taken by Mexico to block genetically modified corn are not based in science and so, a violation of the trade agreement, USMCA.7
A report developed from the panel appointed to determine whether Mexico could limit importation of genetically modified corn applied the standards for limiting imports — the phytosanitary rules of the USMCA.
The USMCA went into effect as international law July 1, 2020. It is the free trade agreement that replaced NAFTA, the North American Free Trade Agreement, which was intended to make more fairness in labor and revising the rules of origin to make it more even-handed for all parties.
This dispute is not new. As early as 2004 the environmental council, the Council on Environmental Cooperation, authorized by NAFTA, reported on the dispute around trade in genetically engineered crops. Mexico opposed GE crops being imported into Mexico based on the precautionary principle, like Europe in the free trade agreement there (GATT). Mexican scientists also produced research that showed the germ seed of traditional corn had been contaminated with genes from genetically engineered corn. This was published in the prestigious scientific journal, Nature; 8but shortly thereafter, the research was found to not be capable of duplication (a test of reliability in scientific research) and the paper was withdrawn from the scientific journal.9
Researchers considered this as an important topic for research.10
Why did the U.S. chose the forum of the USMCA mechanism for dispute resolution rather than the broader GATT (General Agreement on Tarriffs and Trade)?
GATT has two mechanisms that are relevant to this dispute. The TBT and SPS Agreements which have evolved as tools to analyze whether protectionism is the underlying reason for trade blocks or reasons deemed legal under GATT. Art. III, requires parties to given imported goods treatment no less favorable than given to nationally produced goods and products. Art. XX of GATT does allow less favorable treatment when it is necessary to protect human, animal or plant health (Article XX(b)).
During the Tokyo Round of trade negotiations, a new layer of obligations were drafted. These govern a special class of domestic regulations. They aim to prevent "technical regulations" (i.e. regulations regarding product specifications, labeling, packaging and other "technical" issues) from restricting trade, and are found in the The Agreement on Technical Barriers to Trade (TBT Agreement) requires countries to avoid creating "unnecessary obstacles to trade" and to ensure regulations are not more "trade-restrictive than necessary" to achieve a "legitimate objective."
Art. XX(b) allowed the European Union to invoke the precautionary principle to block the importation of genetically modified beef, and that is the same legal argument that was made by Mexico in the Presidential decree. Most recently in 2013, the EU was allowed to rely on the Precautionary Principle for a ban of a pesticide.11 Although these opinions are not binding on the next dispute, they are certainly informing as guidance.
Strategically, looking to the well-defined dispute mechanism of the USMCA with a panel report narrowly focused on GE corn, without the history of upholding the precautionary principle for many trade issues in Europe appears a better course of action for the U.S..
Science and Traditional Corn
There are scientific reasons to preserve traditional corn, not the least of which is genetic diversity. One of the major criticisms of genetically modified corn is that its uniform genome is susceptible to disease that would completely destroy the entire crop, leading to mass starvation. Where you have genetic diversity of varieties of corn, at least some are likely to survive a crop disease.
Traditional corn crops are not threatened by corn used for human and animal food, and so traditional corn can remain safely grown in Mexico.
However, the ban is for corn for human consumption, and for that there must be a scientific basis that it is a threat to public health. There has been no research to date to show that genetically modified crops are a threat to public health. For that reason, the USMCA panel found for the U.S., leading to the ultimate conclusion that GE corn will continue to make up the major component of dough and tortillas in Mexico.
Without corn, there is no country, Sin Maíz No Hay País
But there are opponents that do not find the economic arguments compelling, nor outweighing the importance of sovereignty over food for a nation’s citizens. There is a slogan in Mexico that is also a national movement, “without corn, there is no country,” which illustrates the importance of corn as food, identity and nationality. Given its importance and the apparent willingness to pay 19% more for corn for all of Mexico’s needs, should it not be another exception to free trade agreements like USMCA? If Mexico is not willing or able to pay the 19% premium to ban U.S. GE corn, and people are starving, then it does not seem rational; but if it is a matter of sovereignty, then Mexico can make that determination, as a sovereign nation. With the U.S. as the biggest supplier and Mexico as the U.S.’s biggest customer with a stated goal of using traditional corn as a matter of sovereignty, there is a lot at stake, and international law favors the economic resolution, at least for now.
https://www.dof.gob.mx/nota_detalle.php?codigo=5609365&fecha=31/12/2020#gsc.tab=0
https://www.reuters.com/markets/commodities/mexico-opens-door-gm-corn-animal-feed-industrial-use-2023-02-14/
https://fas.usda.gov/data/commodities/corn
https://crsreports.congress.gov/product/pdf/R/R48083
Biotechnology Innovation Organization, Implications and Consumer Price Impacts of Mexico’s Biotech Corn Ban, October 3, 2022 at https://www.bio.org/press-release/implications-and-consumer-price-impacts-mexicos-biotech-corn-ban
https://www.reuters.com/markets/commodities/us-demands-mexico-explain-science-behind-gmo-corn-ban-2023-02-10/
https://ustr.gov/about-us/policy-offices/press-office/press-releases/2024/december/united-states-prevails-usmca-dispute-biotech-corn
David Quist and Ignacio H. Chapela, “Transgenic DNA Introgressed into Traditional Maize Landraces in Oaxaca, Mexico,” Nature, vol. 414 (November 29, 2001), pp. 541-543.
https://newsarchive.berkeley.edu/news/media/releases/2001/11/29_corn.html
https://sciences.ucf.edu/biology/d4lab/wp-content/uploads/sites/23/2021/11/Mexican-corn.pdf
https://www.pan-europe.info/press-releases/2021/05/court-justice-eu-backs-eu-decision-restrict-neonicotinoids-2013-based