When genetically engineered crops hit the market two decades ago, some farmers stayed with old-school seed.

For a time, the move paid off. Traditional seed cost less than the biotech stuff.  Crops commanded a small premium over the new genetically modified organisms that had consumers skittish.

But soon the yields offered by gene-tinkered seeds got stronger and more tempting for large-scale farmers..

Agriculture increasingly relies on GMOs. Particularly in the horizon-swallowing grain fields that blanket the Midwest, biotechnology rules.

That’s why you’ll probably eat some for breakfast. And lunch and dinner.

Polls show rising consumer fears about eating GMOs. Yet those worries may come too late to matter.

Even with revived shopper anxiety over yet-to-be-confirmed dangers, the large-scale farming that fills American stomachs remains more sold than ever on biotechnology.

Some niche sectors now command higher prices for grain raised without genetically modified crops, aided by a recent uptick in consumer worries.

But the very dominance of GMOs makes those niche crops harder to deliver. Even when companies try to avoid GMOs, they can’t. Plants without the biotechnology can become pollinated by others miles away that do have it. Or harvested grain gets accidentally mixed together in field machinery, in trucks, in on-farm grain bins or in commercial elevators.

Most contracts for GMO-free supplies set limits for contamination for genetically modified levels below 2 percent. That can be a risky promise in today’s agriculture.

“It’s really hard to hit zero,” said Max Fisher, an economist for the National Grain and Feed Association. “They test every truckload and they reject any truckload that exceeds the tolerance. … It’s a real risk.”

Lingering resistance to genetically modified crops, paired with its dominance in the American Grain Belt, creates trouble for farmers and consumers alike.

New food

Lab-designed plants have drawn controversy ever since the FLAVR SAVRtomato – valued for its long shelf-life, derided as more saver than flavor – won approval for human consumption in 1994.

The U.S. Food and Drug Administration decided then, in the face of much criticism, against mandatory labeling of products containing GMO ingredients. Why label something, after all, if the government sees it as no more dangerous than anything else in the grocery aisle?

That, said MARION NESTLE, was a mistake.

“If it were labeled, it would be obvious by this time to people that they were eating it without a catastrophe,” said the New York University professor of nutrition food studies and public health.

She sides with the scientific consensus that there’s no evidence of a health threat from GMOs. The food has been widely consumed for decades without any research suggesting a problem. She acknowledges reasonable theories that it might someday be proven a risk – exposing people to allergies they wouldn’t associate with a can of corn or a serving of tofu – but only theories.

“You can’t prove that something is perfectly safe,” said Nestle, the author of “Food Politics.”

An American Medical Association panel concluded that after 20 years of consumption, “no overt consequences on human health have been reported and/or substantiated.” The U.N. World Health Organization CONCURSSO DOES the National Academy of Sciences.

Sen. Claire McCaskill, D-Mo., RECENTLY CRITICIZED people who agree with scientific consensus that carbon emissions contribute to climate change but who “ignore the science” that GMOs are safe.

The FDA has now cleared dozens of genetically engineered foods.

Today, 89 percent of U.S. corn acres are genetically engineered. For soybeans, it’s 94 percent.

The biotechnology left an even more dramatic impact in Kansas, where 95 percent of corn stalks spring from GMO seed.

What’s more, corn varieties genetically engineered to survive drought have taken over fields that for generations produced wheat. Corn acreage on non-irrigated fields in Kansas doubled in less than 20 years.

Although GMO wheat strains have been developed, they haven’t been introduced into the market. That’s largely, analysts say, because consumers make a closer connection to wheat and a specific food, bread, than they do with other grains.

Fields planted with GMO crops typically deliver higher and, critically, more reliable yields. That’s their appeal – baked-in characteristics that help them grow with less water, impervious to herbicides, insect-resistant. So while GMO-free crops cover about 11 percent of the country’s corn acres, they make up less than 7 percent of U.S. corn production.

While American farming quickly took to the biotechnology, other parts of the world accepted it more grudgingly.

European and Asian markets have long resisted GMOs, partly because of consumer attitudes and partly out of efforts to give their farmers protection against imports from America’s prolific ag exports.

Designer diet

Americans – some less aware than others – have been eating GMO food for years. Most, every day. The Grocery Manufacturers Association ESTIMATES that between 70 and 80 percent of the food Americans consume includes genetically engineered ingredients.

Only the most fastidious attention to diet can avoid GMO food. It’s in virtually every nondiet soft drink. Corn syrup delivers the sugary taste to any number of processed desserts. Soybeans are at least as common.

Consumer reports FOUND that even some products labeled GMO-free contain high levels of genetically engineered grains.

In April, CHIPOTLE DECIDED to reject any food from genetically modified plants. The Mexican-casual chain stands most prominently among a mounting number of food sellers edging away from what critics dub “Frankenfood.” Kellogg is on a path to make its Kashi cereals free of genetically modified grains by next summer.

Yet Chipotle has been sued by a California consumer challenging its GMO-free claims. After all, the Coke you pour has been sweetened with corn.

The restaurant chain concedes its shift was less than dramatic, mostly switching away from soybean oil to cook its chips and taco shells.

Meanwhile, its beef, pork and chicken are raised with the help of GMOs. The livestock feed that fattens them comes from genetically engineered corn and soybeans.

“GMO animal feed is certainly on our radar,” company spokesman Chris Arnold said in an e-mail to the Star. “Given the reliance on corn and soy in animal agriculture, however, and the prevalence of GMO corn and soy production in the U.S., moving to meat from animals raised without GMO feed would be very difficult short of buying organic. There simply wouldn’t be enough organic meat produced in the U.S. to meet our needs.”

Whether you care likely depends on how particular you are about what you eat and your level of education.

Consumer worries ARE GROWING. A Pew Research Study this year found that roughly three in five Americans believe eating genetically modified food is unsafe. That view held steady among both Democrats and Republicans and most other categories, although women were slightly more wary of GMOs than men. An even bigger majority, two-thirds, said scientists don’t clearly understand the health effects.

The only group that believed eating genetically engineered food was safe were those with graduate degrees.

ANOTHER PEW SURVEYof members of the American Association for the Advancement of Science found 88 percent of scientists believed it was generally safe to eat genetically modified food.

“What stands out is that people say they don’t think scientists have a full understanding,” said Cary Funk, Pew’s associate director of research.

That outlook drives efforts to require labels on packages containing GMO ingredients. Connecticut and Maine both have laws, but their rules kick in only if several other states follow suit. Vermont has a labeling law scheduled to take effect next year.

The movement has gained little traction in the legislatures of grain-raising states. In the U.S. House, Republican Mike Pompeo of Wichita has championed a bill that would bar states from requiring GMO labels.

Julie Nielson said that seeing a rise in miscarriages among her cattle after they ate GMO corn silage tipped her against the technology and toward a shift to organic farming.

Part of her farming operation near Barnard in western Missouri is now CERTIFIED to sell products under organic labels. But the shift has been difficult.

“Everything is trial and error,” she said. “With conventional farming, you just do what the chemical company says, and your crop grows. … Organic is something you need to do to learn.”

They’ve sold most of their harvests for livestock feed where Nielson said standards over contamination from GMO grain – that stuff that may have drifted from a neighbor’s field or fallen into a grain bin – “aren’t nearly as picky.”

At Heartland Mill in Marienthal, Kan., company president Mark Nightengale said demand for his organic flour tripled in 10 years. But finding supplies of non-GMO corn and soybeans, he said, “is pretty hard to do in today’s world.” Last year’s drought meant having to buy grain from outside North America.

He thinks a shift in farming will change those dynamics.

“I thought the American people had accepted GMOs,” Nightengale said. “That’s changing.”

The production numbers, however, suggest the hold of genetically engineered crops is solidifying. Art Barnaby, an agricultural economist at K-State’s research and extension office, said switching away from GMOs would require consumers to pay more and the industry to retool – spending dramatically to better separate grain that’s not genetically modified. In fact, he thinks GMO wheat will enter the market in the coming years.

“Modern farming is all about bulk grain,” he said, “and producing it as cheap as possible.”