In Mexico, the birthplace of corn, a network of organizations has been campaigning since 2007 for the protection of native crops against GMOs and for the right to healthy and nutritious food. The campaign created for Day of Corn and succeeded in halting genetically modified cultivation. In March, the Mexican Congress granted it constitutional protection. Adelita San Vicente Tello, a leading figure in the campaign, reviews the history.
Adelita San Vicente Tello is an agricultural engineer specializing in agroecology with a master’s degree in rural development. For years, she led the Sin Maíz No Hay País (No Corn, No Country) campaign, which achieved a milestone in the history of Mexico and the world. In March of this year, Congress amended Articles 4 and 27 of the Constitution to declare the country a territory free of genetic modification in corn, a staple food in those latitudes. Mexico, which resisted pressure from the US transgenic lobby, celebrates the Day of Corn every September 29. And this is the first year that this crop is protected by the Constitution.
Without Corn, There Is No Country
The Sin Maíz No Hay País (No Corn, No Country) campaign began in 2007—“18 years ago, it has come of age,” jokes San Vicente Tello—as a coalition of peasant, human rights, environmental, and scientific organizations, a network of networks. The precedent had been a network of peasant organizations that came together in 2001 under the name “El campo no aguanta más” (The countryside will not take it anymore).
In 2007, the reason for expanding that network—which was joined by organizations such as Greenpeace—was the renegotiation of the North American Free Trade Agreement (NAFTA) between Mexico, the United States, and Canada, signed in 1994. The proposal of the organizations that make up the campaign was to renegotiate the agricultural chapter, because “it has been very decisive for agriculture and food in Mexico,” says the agricultural engineer, who asserts that expanding the network of organizations showed that “the problem of the countryside also concerns people in the city.”
“Save the countryside to save Mexico. Put Mexico in your mouth!” was the slogan used to rally citizens. “Although we initially demanded that the government renegotiate NAFTA and then not allow the planting of genetically modified corn, there came a time when, thanks to human rights organizations, and especially Father Miguel Concha, we understood that we had rights and that we didn’t just have to demand action from the executive branch. So, we had to demand our rights and use legal instruments,” says San Vicente Tello, also a member of the Union of Scientists Committed to Society.
That was the first step in initiating a class action lawsuit in 2013 to protect corn by suing companies such as Pioneer—now merged into Corteva Agriscience—and the executive branch itself for “contaminating corn biodiversity.” The injunction was ruled in favor of the collective, and since then, the planting of genetically modified corn has been suspended. According to the National Commission for the Knowledge and Use of Biodiversity (Conabio), of the 220 existing corn varieties, 64 are present in Mexican soil and 59 are native.
“It was a hugely important achievement and led us to other struggles, such as including the right to nutritious, sufficient, and high-quality food in the Constitution and, more recently, including a ban on the planting of genetically modified corn in Mexico in the Constitution,” says the agricultural engineer, who was the legal representative for the class action lawsuit that succeeded in legally suspending the planting of genetically modified corn.
As part of the campaign, in 2009, the Day of Corn began to be celebrated every September 29. “It is a celebration like those of the indigenous peoples and farmers, with many festivals around the agricultural cycle. A harvest celebration that takes place in many parts of the country and in which farmers give you corn at the foot of the field. In 2009, we did it in Mexico City’s main square, the Zócalo, and we managed to replicate it in more than 100 places, even in Germany. It was a success,” recalls San Vicente Tello, noting that the date was established and made official with the support of the Morena government—a political force founded by Andrés Manuel López Obrador, who has been in power since 2018, now under the leadership of Claudia Sheinbaum.
“The campaign has broken new ground as a social movement in favor of the countryside and nutritious, sufficient, and high-quality food,” says the agricultural engineer.
The Transgenic Threat to Corn
Mexico’s Law on Biosafety of Genetically Modified Organisms (GMOs) requires that studies have an experimental phase, a pilot phase, and then an open-field phase. Pressure from multinationals to introduce their varieties raised alarms when permits were obtained for the experimental phase and cases of cross-contamination between native and genetically modified corn were found. “Corn is a cross-pollinated crop. Each grain has its own father, so to speak. So pollen can fly and, as has been demonstrated, can quickly lead to contamination with GMOs. It was even found in the mountains, in a very remote area, and that was a warning sign. Corn is being contaminated!”
The consequences of the contamination of native crops with GMOs have repercussions “at all levels,” says San Vicente Tello, referring to research by the National Council for Science and Technology (Conahcyt) that has shown how they can cause physiological changes, as well as concerns about the association of these GM crops with glyphosate.
“But what worries us most is the issue of patents. Do we know that with GMOs, genetic engineering companies have managed to patent life? Something that was not possible before,” she points out, adding that, in addition to contaminating native crops and health through the use of agrochemicals, companies could end up charging for their patents.
“We would lose and be subject to Monsanto, now Monsanto-Bayer, coming to collect property rights. For our millenary plant!” insists the agronomist, recalling the years she spent visiting the offices of the judiciary to promote the lawsuit that stopped corn cultivation in Mexico.
“When we filed the class action lawsuit, we went to see, I don’t know how many judges, more than 100 judges; every time we told them that corn was in danger, the judges themselves reacted. What is our corn like? No, how can they take something as sensitive as ours?” he recalls.
“Corn Is In Our Heart”
Corn originated not only in Mexico but also in the region known as Mesoamerica, which stretches from Mexico south to Nicaragua and Costa Rica. “This area was where corn was first domesticated and constantly diversified. Here are the simple types that are the oldest wild relatives. This is very important because it is the genetic reservoir for the reproduction of all the corn that exists in the world, which is now the most important food crop. Not only because it is used in most industrialized products, either in the form of starch or sugar, but also because of its biological characteristics of adaptability,“ explains San Vicente Tello, adding: ”Corn came out of Mesoamerica and conquered the world.”
The agricultural engineer points out that this is due to its great adaptability, which allows it to grow at 3,500 meters above sea level in Peru or on the plains from South America to South Africa and from there to Eastern Europe. In addition to its adaptability, new benefits of each species continue to be discovered, which are very valuable in the face of climate change. In Oaxaca, a region in southern Mexico, corn was discovered whose roots fix bacteria that allow nitrogen to be fixed in the soil.
Its great adaptability, explains San Vicente Tello, led to this ancient crop being the one on which most genetic modification experiments have been carried out and even being the crop with which the path of “genetic improvement” of the so-called Green Revolution of the late 1960s began. “We call it ancestral improvement,” counters the campaign member. Norman Borlaug, the American agronomist and geneticist known as the father of the “Green Revolution,” traveled to Mexico and created Cimmyt (International Maize and Wheat Improvement Center) there.
“For Mexicans, corn is a sign, a symbol of identity. Some say that Mexico smells like corn. Morning, noon, and night, it is our main food. So, in Mexico, it is extremely important. That is why the logo for the Day of Corn features a corn heart. Corn is in our hearts,” says San Vicente Tello.
An Dxample from Mexico in the Fight Against Genetically Modified Wheat
In October 2020, Argentina approved HB4 genetically modified wheat, the world’s first genetically modified wheat—patented by Bioceres-Florimond Desprez—and, two years later, authorized its commercialization after it was approved in other producing countries such as Brazil, Australia, and New Zealand. Farmers’, environmental, and scientific organizations, as in Mexico, rejected its approval and denounced the dangers, but they were unable to get the executive branch to back down or the judicial branch to confirm the precautionary measures presented.
With his experience at the forefront of the Sin Maíz No Hay País (No Corn, No Country) campaign, San Vicente Tello points out that, like all GMOs, wheat represents “a great risk.” “We already know what it has done to health and how this industrialized agriculture has advanced in the Southern Cone, which is sadly called the ‘United Republic of Soy. It is a long struggle, as we have always said, it is a struggle for life and we will not give up. I think that the Argentine people are also wise and will find their own ways to continue fighting,” he said.
Original text by Ana Valtriani published in Agencia Tierra Viva on October 2, 2025.
Photos: Sin Maíz, No Hay País Campaign.
Translation by Schools for Chiapas.
*Ana Valtriani is an agricultural engineer and member of the Network of Freelance Professors on Food Sovereignty (Red CALISAS).