Roundup, Monsanto’s popular glyphosate herbicide, is used with Roundup Ready seeds. Roundup Ready means that the seeds have been developed to survive the chemical application. The first Roundup Ready soybeans were approved for planting less than 20 years ago. There is now Roundup ready alfalfa, corn, cotton, canola and sugar beets. The seeds produce crops that are sterile, ensuring that farmers must buy new seeds for each year’s planting. Roundup was touted as a safer weedkiller, replacing the older, more toxic 2,4-D herbicide. For a time, it worked.

For the agrochemical companies, the answer is always a new, stronger chemical cocktail that can combat the resistant superweeds developed in response to the last chemical solution. That's where Enlist Duo, a solution for the superweeds that now resist Roundup, comes in.

Then a few of the targeted weeds or insects prove strong enough to survive. With their genetic advantage, they multiply and eventually dominate their species. A new generation of pests emerges, with a genetic resistance to the pesticide. Farmers apply more of the product to knock out the stronger nemesis, and the cycle continues until the weed or insect resistance is so strong that the product doesn't work against them. And then the game begins again.

Here’s how it typically goes: The agrochemical escalation begins when a new herbicide or pesticide is developed and approved. The chemical company promises that the new product will provide better protection against broadleaf weeds or boll weevils or problem grasses or corn borers or some other plant or insect pest. Farmers buy the new pesticide, and for a time, it works — that is, it works to reduce specific weeds for the farmers who use it. But even that success comes at the risk of poisoning neighboring farmers’ crops and people and animals exposed to chemical drift.

The EPA’s approval of a new cocktail of old herbicides signals further escalation in the war on weeds, increased industrialization of agriculture and yet another victory for the agrochemical giants. If Americans want a food system that is less chemical-dependent and healthier for people and the rest of the environment, they need to understand the game chemical companies play with superweeds and their superproducts.

In October the U.S. Environmental Protection Agency approved the registration of Enlist Duo, a new herbicide to fight superweeds resistant to other weedkillers. The chemical combines glyphosate, originally developed and marketed by Monsanto as Roundup, with the older, more toxic 2,4-D, one of the ingredients in Agent Orange. The approval applies to six states, and the EPA is accepting public comment until Dec. 15 to register the pesticide in 10 additional states. The registration, which came a month after the U.S. Department of Agriculture approved new corn and soybean seeds genetically engineered to resist both herbicides, is subject to a six-year limit and some monitoring requirements.

Enlist Duo is good for agrochemical companies but not so much for corn and soybean farmers, who are on a chemical and GMO seed treadmill.

But greater exposure to glyphosate led to the emergence of new generations of Roundup-resistant superweeds. By 2012, half of U.S. farm fields had resistant weeds, and the number of acres with glyphosate-resistant weeds was growing. “Total resistant acres increased by 25 percent in 2011 and 51 percent in 2012,” Mother Jones’ Tom Philpott reported last year. According to him, more than a quarter of U.S. farms have at least two resistant weed species.

Is the new round of more effective — read: more toxic — pesticides and pesticide-resistant seeds a solution or a problem?

Agrochemical companies see a solution. They stand ready to produce new generations of pesticides and genetically modified seeds as superweeds defeat the herbicides and seeds that they had previously sold to farmers. Superweeds increase the market for pesticides and the patented GMO seeds. Enlist Duo and the new corn and soybean seeds are this year's solution.

However, the agrochemical solution comes at a cost.

The problems start with the increasing amount of chemicals poured into the soil and waterways. “Even in remote areas — far from pavement runoff or agricultural byproducts — 65 percent of streams contain traces of one or more pesticides,” journalist David Biello reported in Scientific American. Pouring more chemicals onto crops increases the amount of poison entering our waterways.

The poisons travel through the air as well. Pesticide drift is the movement of chemicals to areas that are not its target. When farmers apply pesticides, the dust or droplets can kill not only the targeted weeds but also a neighboring farm’s plants. “Volatile 2,4-D fumes can drift for miles” and “exposure to volatile fumes” can cause injury days after pesticide is applied, depending on temperature and humidity, according to a University of Maryland fact sheet for grape growers. Leaving a buffer zone between sprayed land and other crops can reduce this effect, but that takes land out of production and reduces farmers’ profits.

Besides, the evolving superweeds can spread to farms that are not protected by the latest chemical cocktail. For example, a farmer who is growing corn — but not Dow Chemical’s specially engineered pesticide-resistant seeds — may face the superweeds. An organic farm, by definition, cannot use the chemicals to combat the superweeds.

These problems have already been observed and reported, but there may be others as well. For example, according to the Center for Biological Diversity, the effects of glyphosate’s widespread use have not been thoroughly studied since it was approved in 1993. Similarly, a recent study from the Massachusetts Institute of Technology found glyphosate residue in foods that may be “linked to a range of health problems and diseases, including Parkinson's, infertility and cancers,” according to Reuters. Environmental groups and plant scientists have warned about risks from the cumulative effects of years of use of glyphosate and other pesticides on human health, wildlife and the water we drink.

Enlist Duo is good for agrochemical companies but not so much for corn and soybean farmers, who are on a chemical and GMO seed treadmill. It does not help farmers who get the effect of superweeds but not the “protection” of the new pesticide. It also will contribute to the deterioration of the quality of soil and water that absorb the increased chemical load.

Spraying pesticides on our fields and food has already created significant environmental and health hazards. Pouring more toxic pesticides on our farms is not a good way to fix those problems.