The deep roots of Mexico’s trade dispute with U.S. over GMO corn

Activists from Greenpeace Mexico protesting the government's lifting of a ban on experimental planting of genetically modified crops. Mexico City, 2003. AP Photo/Jose Luis Magana.

The history of the current dispute between Mexico and the U.S. over genetically modified corn has roots much deeper than the presidential decree that set it off. Opposition to GMO crops in Mexico has simmered for 20 years, born of worries that ancient landrace varieties of corn that are central to the country’s social, cultural and economic well-being would be lost.

In late 2020, when Mexican President López Obrador mandated the phase-out of GMO corn by 2024, he was in part fulfilling a campaign promise to those opponents. The president vowed to replace GMO corn with “sustainable and culturally appropriate” alternatives. But the decree, which also would ban the use of the controversial weedkiller glyphosate, alarmed U.S. farmers, who grow mainly GMO corn and sell much of it to Mexico. They and their allies in Congress urged the Biden administration to hold Mexico accountable under United States-Mexico-Canada Agreement (USMCA).

“We have no opinion on how Mexico regulates its own farming, but if you sign up to a trade deal, then you’re getting into the business of deciding what the producers can produce in the other country that you want to buy,” said Angus Kelly, director of public policy, trade and biotechnology for the National Corn Growers Association, earlier this month.

The two sides have conducted a flurry of negotiations in recent weeks. On Friday, Mexico’s Foreign Secretary Marcelo Ebrard and other senior officials offered a possible compromise in a Washington, D.C., meeting with Agriculture Secretary Tom Vilsack and U.S. Trade Representative Katherine Tai. “The Mexican delegation presented some potential amendments to the decree in an effort to address our concerns,” Vilsack and Tai said in a joint statement. “We agreed to review their proposal closely and follow up with questions or concerns in short order. There is a joint recognition that time is of the essence and we must determine a path forward soon.”

Mexican officials characterized the talks as constructive. In a statement they reiterated their food-security policy objectives: “To preserve its bio-cultural heritage as the center of origin of its roughly 60 landrace corn varieties; to continue to guarantee its self-sufficiency in corn for tortilla use; and to strengthen food security in North America.” The two sides plan to meet again in January, “with a view toward consolidating a mutual understanding.”

Even if an agreement is reached, the kerfuffle makes clear the differences in how GMO corn is treated in both countries. The U.S. has embraced it since the mid-1990s, and more than 90 percent of the crop grows from seeds modified through biotechnology. Most of that corn is used to produce ethanol and animal feed, with some also used as an ingredient in processed food and beverages. Mexico, meanwhile, predominantly produces non-GMO corn for human consumption, most notably for the ubiquitous tortilla. Imports of yellow corn, primarily from the U.S., have risen sharply in the last two decades to feed the country’s growing livestock and poultry industries. But the current administration has launched policy initiatives aimed at increasing domestic corn production, including direct payments to support  small- and medium-scale farmers.

Activists demonstrate against Monsanto and the commercial sowing of transgenic corn in Mexico City, on November 5, 2012. Photo by Pedro Pardo/AFP via Getty Images.

Corn, or maize, holds deep cultural significance in Mexico, its recognized birthplace. In the early 2000s, the nation’s corn became a cultural flashpoint after traces of genetically modified corn were found in native varieties in rural communities. Such concerns later gave rise to a campaign called “Sin maíz, no hay país” (without corn, there is no country), which lobbies to keep GMOs out of Mexico.  Well-documented contamination from what was believed to be illegal cultivation led to demands, street protests and legal maneuvering to protect landrace corn. Conservationists, Indigenous communities and traditional farmers sought to preserve the country’s heritage seeds as agrochemical giants like Bayer-Monsanto pushed to grow GMO corn in Mexico.

Environmentalists in Mexico say GMOs can contaminate landrace corn through cross-pollination and that the pesticides used in conjunction with the modified seeds endangers public health and harms biodiversity. They view the planned ban as an important step in the transition to a more sustainable farming system that can produce healthy food, protect the environment and make the most of natural resources. “We call on the federal government to not give in to U.S. pressure, to defend the right to food sovereignty,” said Viridiana Lázaro, a food and agriculture campaigner for Greenpeace in Mexico.

Greenpeace is part of a coalition of individuals, small farmers, consumers, scientists and others who in 2013 filed a class-action suit in Mexican federal court against Monsanto, Syngenta, Dow and Pioneer/DuPont to protect landrace corn strains from genetic contamination and modification. Despite appeals by the companies, a court injunction that halted GMO corn plantings on test plots in northern Mexico remains in place. In 2017, a study found traces of GMOs in tortillas and other widely consumed foods, further stoking opposition to GMO corn. The case is now before the Mexican Supreme Court.

The Mexican government has never allowed commercial cultivation of GMO corn, but over time it has become more dependent on imports — particularly after implementation of the 1994 North American Free Trade Agreement (NAFTA), the predecessor to USMCA that eliminated trade restrictions. In 2021, Mexico imported 16.9 million tons of corn from the U.S., where 93 percent of the crop is genetically modified. Most of the imported corn goes to livestock, pork and poultry producers, but it’s also used for processed foods such as cereals, syrup and sauces. And although Mexico is largely self-sufficient in the white corn used to make the tortillas that accompany daily meals, last year’s imports included 862,000 tons of white corn — much of it GMO — to supplement domestic production. Through October of this year, Mexico purchased 13 million tons of U.S. corn, of which 455,000 tons was white corn, according to the U.S. Department of Agriculture.

The USMCA encourages trade-related cooperation in agricultural biotechnology, a field that includes GMO crops. But López Obrador insists that his country is under no obligation to import genetically modified crops under the treaty. “When deciding between health or trade, we opt for health,” he said in November after a meeting with Vilsack. The treaty offers mechanisms to address controversies, he said, “but we have elements to defend ourselves on why genetically modified corn isn’t allowed.”

Although China replaced Mexico as the largest importer of U.S. corn worth $5.1 billion last year, Mexico remains a close second with $4.7 billion. Mexico now imports about 40 percent of its corn, and to offset an expected shortfall if the ban is enacted, the administration has floated the idea of seeking non-GMO imports from other countries, including Argentina and Brazil.

David Gantz, an international trade expert at Rice University’s Baker Institute for Public Policy, said the dispute is “a huge risk to Mexico’s future economic problems if they don’t find some way of at least mollifying the U.S. on these issues.” 

A ban of GMO corn would be detrimental to both countries, according to a study published in October by World Perspectives Inc., a D.C.-based consulting firm, that was commissioned by agricultural groups from the U.S. and Mexico. The price of non-GMO corn could rise 48 percent the first year and, during the same period, Mexico would have to pay an additional $571 million for imports to offset the loss of American corn, the study concluded. In the United States, numerous jobs could be lost, and farmers would lose an estimated $3.56 billion just in the first year.

The NCGA’s Kelly said Mexico’s ban singles out not only white corn, but also food-grade yellow corn used as an ingredient in many consumer products. An inability to export such crops to Mexico would be devastating for growers in several states, he said. “It’d be bad for the U.S. corn farmers and for the rural economy. I’m not trying to pretend that we’re not worried about it.”

López Obrador, whose six-year term ends in October 2024, has suggested that health regulators in both countries conduct studies on whether GMO yellow corn can harm human health. 

Kelly maintains that the Mexican president’s concerns over public health from GMO corn has no basis in science and is at odds with major food safety agencies. To ban it based on human health risk “just doesn’t bear out in a quarter century of data.”

Research generally suggests that GMO foods are safe to consume, but concerns persist over their potential long-term effect on human health and the environment. Studies on the health impact of glyphosate, a key ingredient in the Roundup weedkiller widely used in GMO corn cultivation, are mixed. The World Health Organization has characterized glyphosate as “probably carcinogenic to humans,” but the U.S. Environmental Protection Agency has concluded the opposite. Nonetheless, Roundup maker Bayer-Monsanto has paid out billions to settle numerous lawsuits from plaintiffs who maintain the herbicide contributed to their cancer.

Critics within Mexico of the planned corn ban, like those in the U.S., express doubts that the country can feed its growing population without the corn imports it has long relied on. Mexico’s largest farm lobby, the National Agricultural Council, has decried his country’s GMO corn policy and warned that it would cause food shortages and higher prices, as well as stifle agricultural innovation. Group president Juan Cortina said it is unfortunate that ideology and activism, rather than science, are shaping the discussion over GMO corn. “We are firm believers that science and technology are what will move us forward,” he told reporters at a recent forum.

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