The Mexican government's push to wean itself off a massive dependence on genetically modified corn imports would upend the country's food supply, including its big livestock sector, industry officials warn.
A 31 December degree banning the use of genetically modified corn over three years has sparked a frenzy of lobbying urging officials to reconsider.
Both the agriculture and economy ministries held high-level meeting with industry representatives this week, according to several participants.
The same decree also calls for a ban on the herbicide glyphosate, used in Mexico by thousands of small and big farms to boost crop yields.
While Mexico, the birthplace of modern corn, has never allowed commercial-scale planting of the grain using seeds containing genetically modified organisms (GMO), it imports millions of tonnes of such corn for its growing livestock sector, among many other industrial uses.
The decree does not detail how the country might replace the supplies.
Jose Cacho, president of Mexico's corn industry chamber CANAMI, said the GMO corn ban is unworkable due to supply chains that for years have developed around them, from livestock to a dizzying array of condiments and sauces that use starches derived from the same corn.
"This decree is completely divorced from reality," said Cacho, whose 25-company group includes top corn millers like Gruma and cereal maker Kellogg, as well as commodity trader Cargill.
A report from the US Department of Agriculture earlier this month described Mexico's policy toward so-called biotechnology as "increasingly uncertain" under President Andres Manuel Lopez Obrador.
Supporters of the decree argue that GMO seeds can easily contaminate native corn strains, and point to research showing glyphosate may cause cancer as well as elevated insect mortality.
Biggest Foreign Market
Mexico is the biggest foreign market for US yellow corn, which is nearly all genetically modified.
Cacho fears the government could interpret the decree to forbid the use of GMO corn in anything ultimately consumed by people, from beef to ketchup.
Mexico imported some 18 million tonnes of mostly GMO corn last season, or around 40% of national consumption.
Mexico produces most of its own white corn, or about 25 million tonnes, used to make the country's staple tortillas, but some white corn is also imported.
Genetically Modified Corn
Nearly all of the available US corn supplies, but also from rival producers in Argentina and Brazil, are genetically modified. That would make it nearly impossible to satisfy Mexican demand without GMO supplies if the decree is broadly interpreted.
Historically, Mexican law has not adopted different standards for approvals of food for human consumption and animal feed, both of which are handled by the health ministry's sanitary protection agency COFEPRIS. It has issued 90 approvals for GMO corn used in human food and animal feed as of last year.
Meanwhile, since late 2019, the environment ministry has stopped all permit approvals for glyphosate imports.
Cacho estimates that prohibiting farmers from using it would lower yields by at least 30%, which he said would likely make the country even more dependent on imports.