Showing posts with label Herbicides. Show all posts
Showing posts with label Herbicides. Show all posts

Friday, June 12, 2020

3379. America's Agriculture is 48 Times More Toxic Than 25 YearsAgo Due to Neonics Use

By Kendra Klein and Anna Lappé, The Guardian, August 7, 2019

More than 50 years ago, Rachel Carson warned of a “silent spring”, the songs of robins and wood thrush silenced by toxic pesticides such as DDT. Today, there is a new pesticide specter: a class of insecticides called neonicotinoids. For years, scientists have been raising the alarm about these bug killers, but a new study reveals a more complete picture of the threat they pose to insect life.
First commercialized in the 1990s, neonicotinoids, or neonics for short, are now the most widely used insecticides in the world. They’re used on over 140 crops, from apples and almonds to spinach and rice. Chemically similar to nicotine, they kill insects by attacking their nerve cells.
Neonics were pitched as an answer to pests’ increasing resistance to the reigning insecticides. But in an effort to more effectively kill pests, we created an explosion in the toxicity of agriculture not just for unwanted bugs but for the honeybees, ladybugs, beetles and the vast abundance of other insects that sustain life on Earth.
What we now know is that neonics are not only considerably more toxic to insects than other insecticides, they are far more persistent in the environment. While others break down within hours or days, neonics can remain in soils, plants and waterways for months to years, killing insects long after they’re applied and creating a compounding toxic burden.
The new study, published in the science journal PLOS ONE and co-authored by one of us, designed a way to quantify this persistence and combine it with data on the toxicity and total pounds used of neonics and other insecticides. For the first time, we have a time-lapse of impact: we can compare year-to-year changes in the toxicity of US agriculture for insects. The results? Since neonics were first introduced 25 years ago, US agriculture has become 48 times more toxic to insect life, and neonics are responsible for 92% of that surge in toxicity.
Looking at this toxic time-lapse, another interesting detail emerges: there’s a dramatic increase in the toxic burden of US agriculture for insects starting in the mid-2000s. That’s when beekeepers began reporting significant losses of their hives. It’s also when the pesticide companies that manufacture neonics, Bayer and Syngenta, found a lucrative new use for these chemicals: coating the seeds of crops like corn and soy that are grown on millions of acres across the country. These seed coatings now account for the vast majority of neonic use in the US.
Neonics are “systemic”, meaning they are water soluble and therefore taken up by the plant itself, making its nectar, pollen, and fruit – all of it – toxic. Only about 5% of a seed coating is absorbed by the plant, the remainder stays in the soil and can end up in rivers, lakes and drinking water with its runoff causing harm to wildlife and, as emerging evidence shows, to people.
This study comes on the heels of the first analysis of global insect populations, which found 40% of species face extinction, with near total insect loss possible by century’s end, driven in part by pesticides, with neonics a particular concern.
For all of this harm, farmers get few, if any, benefits from neonic seed coatings. According to the US Environmental Protection Agency, they provide “little or no overall benefits to soybean production”, though nearly half of soybean seeds in the US are treated. Similar analyses have found the same for corn, yet up to 100% of US corn seeds are treated.
All this risk without reward has led some regulators to take action. The European Union voted to ban the worst neonics in 2018. But the US government has so far failed to act. Chemical company lobbying can explain much of this inaction. Bayer, maker of the most widely used neonics, spent an estimated $4.3m lobbying in the US on behalf of its agricultural division in 2017.
Not only has the EPA stalled scientific review of neonics, last year, the Fish and Wildlife Service reversed an Obama-era ban on use of these dangerous insecticides in wildlife refuges. Congress could change this. Democratic representative Earl Blumenauer’s Saving America’s Pollinators Act would ban neonicotinoids and other systemic, pollinator-toxic insecticides. The bill has 56 co-sponsors, but faces a major hurdle clearing the House agriculture committee given that the chairman representative, Collin Peterson, a Democrat from Minnesota, counts Bayer and the pesticide industry’s trade association, Croplife America, among his top contributors.
Beyond a ban, we need a concerted effort to transition US agriculture away from dependence on pesticides and toward ecological methods of pest control. We already know how to do this. Research shows that organic farms support up to 50% more pollinating species and help other beneficial insects flourish. And by eliminating neonics and some 900 other active pesticide ingredients, they protect human health, too.
More than five decades ago, Rachel Carson warned that the war we are waging against nature with toxic pesticides is inevitably a war against ourselves. That is as true today as it was then. For the sake of the birds and bees – and all of us – this war must end.
  • Kendra Klein, PhD, is senior staff scientist at Friends of the Earth US
  • Anna LappĂ© is the co-founder of two national food and sustainability organizations and is working on a book on pesticides and our food

Wednesday, June 28, 2017

2641. California Adds Glyphosate to Cancer Watchlist


By Jake Johnson, Common Dreams, June 27, 2017

In a move celebrated by scientists and activists, California on Monday announced it would add glyphosate—the active ingredient in the Monsanto-produced weed killer Roundup—to its list of chemicals known to cause cancer.

The decision, made by California's Office of Environmental Health Hazard Assessment (OEHHA), was reportedly precipitated by the World Health Organization's classification of glyphosate as a "probable carcinogen" in May of 2015.

"California is required under the Safe Drinking Water and Toxic Enforcement Act of 1986, better known as Proposition 65, to publish a regularly updated list of chemicals thought to cause cancer or birth defects," Newsweek reported.

Monsanto has been quick to respond to the move; as USA Today's Emily Bohatch noted, Monsanto is appealing a ruling on a case it brought against California last year, when the OEHHA first attempted to add glyphosate to its list of cancer-causing agents. 

In response to the agrochemical giant's legal maneuvering, activists and scientists have insisted that Monsanto's motive is profit alone—not scientific accuracy or the health of the public—and hailed California's decision as a step in the direction of justice.

The Center for Biological Diversity (CBD) noted in a press release on Monday that a recent analysis "found more than half of the glyphosate sprayed in California is applied in the state's eight most impoverished counties."

"The analysis also found that the populations in these counties are predominantly Hispanic or Latino," CBD continued, "indicating that glyphosate use in California is distributed unequally along both socioeconomic and racial lines."

Nathan Donley, a former cancer researcher and a senior scientist at the CBD, called California's move "remarkable" and congratulated the state for standing up to "special-interest politics [that] hamstring our federal government from taking action to protect people from this dangerous pesticide."

"California's decision makes it the national leader in protecting people from cancer-causing pesticides," Donley concluded. "The U.S. EPA now needs to step up and acknowledge that the world's most transparent and science-based assessment has linked glyphosate to cancer."

Friday, July 17, 2015

1935. Ruthless Power and Deleterious Politics: From DDT to Roundup

By Evaggelos Vallianatos, Independent Science News, July 17, 2015
DDT, Time Magazine, 1947
Morton Biskind, a physician from Westport, Connecticut, was a courageous man. At the peak of the cold war, in 1953, he complained of maladies afflicting both domestic animals and people for the first time. He concluded that the popular insect poison DDT was the agent of their disease. DDT, he said, was “dangerous for all animal life from insects to mammals.”

The Reign of DDT
Yet, he was astonished at what little was done to restrict or ban DDT. On the contrary, officials and scientists defended it:

[V]irtually the entire apparatus of communication, lay and scientific alike, has been devoted to denying, concealing, suppressing, distorting… [the bad news about DDT]. Libel, slander and economic boycott have not been overlooked… And a new principle of toxicology has… become firmly entrenched…: no matter how lethal a poison may be for all other forms of animal life, if it doesn’t kill human beings instantly, it is safe. When… it unmistakably does kill a human, this was the victim’s own fault – either he was “allergic” to it… or he didn't use it properly (Biskind, 1953).”

The warnings of Biskind went nowhere. The Pentagon was testing nuclear weapons above ground and agribusiness was expanding its conquest of rural America — and the world. The strategic interests of the Pentagon coincided with those of agribusiness.

Rachel Carson, the author of “Silent Spring,” listened to Biskind. She denounced the hegemony of chemical pesticides, “the sinister and little-recognized partners of radiation in changing the very nature of the world – the very nature of its life.” She said America’s single-crop farming clashes with how nature works.

Instead, “we allow the chemical death rain to fall…. The crusade to create a chemically sterile world seems to have engendered a fanatic zeal on the part of many specialists and most of the so-called control agencies… there is evidence that those engaged in spraying operations exercise a ruthless power.” (Rachel Carson, Silent Spring)

Meanwhile, federal agencies and official science pretended nothing was wrong. The US Environmental Protection Agency, born in 1970, had to start from the beginning with toxic chemicals some 17 years after Biskind’s complaint. The political and economic forces of agribusiness, the chemical industry, and politicians forged an unofficial alliance between the Pentagon and big agriculture, with agriculture borrowing the Pentagon’s chemical warfare strategy for American farmers. Furthermore, the missionaries of agricultural industrialization adopted and spread the profitable new approach to chemical danger — what Biskind aptly called “a new principle of toxicology” — that still reigns supreme among the practitioners of conventional science and politics in the early twenty-first century. Like a gigantic octopus, the chemical industry put its tentacle all over Congress, the White House and land grant universities.

No wonder most toxic chemicals have been entering the market without being tested for health and environmental effects. Only the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) and the food and drug part of the Food, Drug and Cosmetic Act require testing of chemicals. The Occupational Safety and Health Act, the Toxic Substances Control Act, the cosmetic provisions of the Food, Drug and Cosmetics Act, as well as all other federal laws require no testing for the chemicals or other products entering the market. This does not prevent the industry men and women say the products of their companies “meet EPA standards.”

DDT came out of that careless chemical culture – and war. DDT was successful in fighting malaria during World War II. For that reason, in 1948, its inventor, the Swiss scientist Paul Miller, received the Nobel Prize for medicine. By then DDT was used widely in America. The US Department of Agriculture “registered” it in 1945.

The popularity of DDT had nothing to do with its presumed “safety.” DDT killed more than insects. DDT doomed birds by making it impossible to give birth to live chicks. Their brittle shell cracked under the weight of the adult bird during hatching. DDT was particularly deleterious to predatory birds, bringing peregrine falcons, osprey, brown pelicans, and bald eagles to the brink of extinction. DDT also killed many insects it had not been designed to target, and also small animals, which ate DDT-poisoned fish and wildlife.

The deathly legacy of DDT and DDT-like chemicals has been a long one. The reason is their chemical properties: DDT belongs to the organochlorines, a huge group of chlorine-based poisons that last for decades in nature while accumulating in the fat of the animal ingesting them.

It was the human effects of DDT that convinced EPA to ban it in 1972. EPA considered DDT “a potential human carcinogen.” By that time, the early 1970s, DDT had contaminated “staple human foods, especially meat and milk.” In 1973, a federal judge did not know what to do since DDT had contaminated nearly all foods.

He said, “Although the cancer aspects of DDT are frightening, the obvious solution to that problem, that is, a total ban on foods containing DDT, is not available. Virtually every food contains some DDT… DDT has presented, and apparently will continue to present a massive dilemma both for EPA and for society.” (USA vs Goodman, 1973)
The same happened to the global environment. In 1979, two Wildlife Society scientists, Steven G. Herman and John B. Bulger, reported that DDT was “the most widespread and pernicious of global pollutants.” (Herman and Bulger 1979).

The Hegemony of Glyphosate
The banning of DDT in America in 1972 did not bring about any rethinking of factory farming and its addiction to deleterious pesticides. In fact, large industrialized and pesticide-dependent farms are now crowding the planet. Their owners preach a war on hunger but in actual practice their war is directed against the natural world and small farmers and peasants. And despite their propaganda for feeding the world, they only produce about a third of the world food. Peasants, not industrialized farmers, feed most of the world’s people (Douwe van der Ploeg, 2014). But industrialized farmers are responsible for huge harm done to the natural world and people. That harm comes in the form of global warming and the poisoning of wildlife, rivers, drinking water, and food.

Other toxins replaced DDT. One that became extremely successful worldwide is glyphosate, the so-called active ingredient of Roundup weed killer. This herbicide is a product of the multinational giant seed and agribusiness company Monsanto.

Glyphosate received its EPA registration in 1974. This was a time of deep corruption in the chemical industry. For a few decades before and after 1974, laboratories widely fabricated “safety” studies of pesticides, other chemicals, and also drugs. The fraud enabled these to benefit from government registration. It opened the doors to sales. I don’t know if glyphosate entered the market through fraud. But I do know 1974, the year EPA registered glyphosate, was a year of corruption for most pesticides. The EPA scientist who uncovered the lab fraud, Adrian Gross, was my friend and colleague.
Just like DDT, glyphosate quickly became a global celebrity. Scientists on the payroll of the industry, including scientists of our land grant universities, declared it “safe.” Farmers, gardeners and lawn keepers adopted it widely.

However, not everybody was happy seeing another weed killer making the rounds all over the world. Glyphosate caught the attention of Don Huber, a retired Colonel from the army’s biological warfare corps and a retired academic scientist from Purdue University where he taught for 35 years. Of all the things he knows about biological weapons and diseases and crops, he is the most concerned about the effects of pesticides on the biological systems making up agriculture. He illustrates his anxiety with the effects of glyphosate on crops.

Glyphosate is more than a best-selling weed killer. It is also a powerhouse of genetic engineering. Its masters have bioengineered crops, called Roundup Ready soybeans, Roundup Ready corn, etc., to resist its killing power. This is music to the ears of farmers who can clear their fields of weeds just by spraying their crops with glyphosate.
Monsanto would like one day to control the world’s food supply. With that imperial purpose in mind, Monsanto has been using seeds, crops, pesticides, and genetic engineering to spread its know-how throughout the planet.

But like other agribusiness giants, hubris keeps it blind to the harm its products may often cause to humans and the natural world. Studies published in 2010 show glyphosate is causing birth defects in frogs and chicken embryos at amounts smaller than those farmers and gardeners leave in food (Paganelli et al. 2010). Older studies document: cancer, endocrine disruption, damage to DNA, and deleterious malformations of the reproductive, neurological and developmental systems of animals, including human beings (Richard et al. 2005; Benachour et al. 2007). Some researchers also link glyphosate to miscarriages afflicting people and livestock. Both the industry, including Monsanto, and government authorities have known about the toxic effects of glyphosate since the 1980s. Yet both industry and regulators have kept the public in the dark.

According to Huber, “glyphosate promotes soil pathogens and is already implicated with the increase of more than 40 plant diseases.” Furthermore, Huber reported that glyphosate “dismantles plant defenses” against disease by immobilizing vital nutrients, which means the growing crop is starved of the nutrients it must have to defend itself against disease and to be nutritious. Such impoverished crops, says Huber, are causing “animal disorders.”

On November 1, 2011, Huber visited England where he made a presentation to the All-Party Parliamentary Group on Agroecology of the House of Commons (Huber, 2011). His main argument was that glyphosate “predisposes plants to disease” and “stimulates pathogens” in the soil. In other words, glyphosate acts by compromising the defense of crops against disease; glyphosate kills the targeted plants (weeds) by becoming a biological war agent, in a sense, boosting disease organisms in the soil while killing disease resistance organisms. For the last 30 years glyphosate has been sterilizing the land of organisms that are essential for the health of crops. Such microorganisms are the highways through which plants absorb essential micronutrients. They are also responsible for fixing up to 75 percent of the nitrogen legumes like soybeans, alfalfa and peas need for protein. By killing microorganisms, glyphosate reduces the ability of crops to take up micronutrients from the earth. These micronutrients, like calcium, nickel, copper, iron, manganese and zinc are essential for the health and nutritional quality of crops and, therefore, the health of animals and people eating these crops. Huber connected the micronutrient deficiencies in crops to evidence of stillborn calves and animal disease.

Civilization Under Threat
Like Morton Biskind in 1953, Huber in 2011 spoke of the danger of a new super weed killer, glyphosate. In both cases, separated by 58 years, we have the sick feeling little, maybe nothing, has changed. The same irresponsible agribusiness activities threaten the possible devastation of American agriculture.

Huber denounces the betrayal of public trust by government, industry and academia. In fact, he cites a letter from 26 university entomologists to EPA in which these scientists complain they are prohibited from doing research because their universities receive money from genetic engineering companies to advance their mission, not the public good. And Huber laments the inexplicable reality of “how willing we’ve been to sacrifice our children and future generations and to jeopardize the sustainability of our entire agricultural infrastructure that is the very basis of our existence as a society.”

In spite of the warnings of Huber and other scientists, the USDA “regulators” of genetically engineered crops continue with business as usual. The EPA “regulators” of pesticides also continue with business as usual. The USDA recently approved 2,4-D for a new genetically modified corn. Apparently, they forgot the “weed killer” 2,4-D was a chemical weapon in the Vietnam War. Like its Agent Orange sibling, 2,4,5-T, the herbicide 2,4-D was contaminated by the lethal 2378-dioxin. Adding 2,4-D to the arsenal of GM crops doesn’t bode well for America and the world.

No More Death Rain
Fortunately, there’s resistance to business as usual. I cited Biskind and Carson but in the late 1960s, biologist Paul Shepard attacked the insanity of industrialization. He said ecology was more than a science. It was a resistance movement. He said ecologists are subversive because they challenge our “right” to pollute the environment, destroy predatory animals, spread pesticides everywhere, contaminate water and food, and appropriate the land for military and industrial purposes. Furthermore, ecology subverts our delusions of unlimited human population, the domestication of all wild places, large-scale manipulation of the atmosphere and the seas, and the extinction of species.

Resistance is now taking a new form: the removal of global toxins, unfortunately, one at a time. In early 2015, the usually timid and agribusiness-friendly, World Health Organization, declared both glyphosate and 2,4-D probable human carcinogens. Following on this modest step, in May 14, 2015, the International Society of Doctors for the Environment, based in Basel, Switzerland, issued an appeal to the European governments: “To immediately and permanently ban, with no exceptions, the production, trade and use in all the EU territory of glyphosate-based herbicides.” The UK journalist, Georgina Downs, echoes that sentiment to include all pesticides.
Humans need a pesticides-free future. We need to appeal to all politicians all over the world to ban permanently and without exception all pesticides. Glyphosate represents all pesticides. Our message and policies should be telling agribusiness companies enough is enough: no more death rain. Monsanto, on the other hand, is building additional facilities to manufacture another weed killer by the name of dicamba in order to mix it up with glyphosate. That way the joint product will be more effective against the super weeds resisting glyphosate.

Pesticides are chemical weapons. They were brought to market under the cover of questionable and often fraudulent science and regulation. They are maintained in farming under the false pretense of feeding the world. They are danger itself; they are biocides. They are simply the money lubricants of giant agriculture. They serve no public purpose. We don’t need them.

References
Benachour et al. (2007) Time-and dose-dependent effects of roundup on human embryonic and placental cells. Arch. Environ. Contam. Toxicol. 53, 126–133.
Biskind, MS (1953) “Public Health Aspects of the New Insecticides,” American Journal of Digestive Diseases 20: 331-341.
Douwe van der Ploeg, J “Peasant-driven agricultural growth and food sovereignty,” The Journal of Peasant Studies 41: 999-1030.
Herman SG and Bulger JB (1979), “Effects of a Forest Application of DDT on Nontarget Organisms,” Wildlife Monographs, No 69: 49.
Hobbelink, H “Hungry for Land Grain, May 2014.
Huber, DM “The effects of glyphosate (Roundup) on soils, crops and consumers” (Presentation to the All-Party Parliamentary Group on Agroecology, House of Commons, UK, 1 November 2011).
Richard S, Moslemi S, Sipahutar H, Benachour N and Seralini G-E (2005) Differential Effects of Glyphosate and Roundup on Human Placental Cells and Aromatase. Environmental Health Perspectives 113: 716-720.
Shepard, P “Ecology and Man – a Viewpoint” in The Subversive Science, ed. Paul Shepard and Daniel McKinley (Boston: Houghton Mifflin, 1969) 9.
United States v. Goodman 486 F. 2d at 855 (7th Cir. 1973).
Evaggelos Vallianatos, Ph.D., is a former EPA analyst. He is the author of hundreds of articles and several books, including “Poison Spring: The Secret History of Pollution and the EPA” (with McKay Jenkins, Bloomsbury Press, 2014).

Thursday, August 14, 2014

1511. Decades of Herbicide Use Yield "Weeds" that Do Not Respond to Herbicides: The Case of Amaranthus Palmeri

By Michael Wines, The New York Times, August 11, 2014
Glyphosate resistant Palmer Amaranth, photo by FireFlyForest.com
WHEATFIELD, Ind. — The Terminator — that relentless, seemingly indestructible villain of the 1980s action movie — is back. And he is living amid the soybeans at Harper Brothers Farms.
About 100 miles northwest of Indianapolis, amid 8,000 lush acres farmed by Dave Harper, his brother Mike and their sons, the Arnold Schwarzenegger of weeds refuses to die. Three growing seasons after surfacing in a single field, it is a daily presence in a quarter of the Harper spread and has a foothold in a third more. Its oval leaves and spindly seed heads blanket roadsides and jut above orderly soybean rows like skyscrapers poking through cloud banks. It shrugs off extreme drought and heat. At up to six inches in diameter, its stalk is thick enough to damage farm equipment.
“You swear that you killed it,” said Scott Harper, Dave Harper’s son and the farm’s 28-year-old resident weed expert. “And then it gets a little green on it, and it comes right back.”
Botanists call the weed palmer amaranth. But perhaps the most fitting, if less known, name is carelessweed. In barely a decade, it has devastated Southern cotton farms and is poised to wreak havoc in the Midwest — all because farmers got careless.
After Monsanto began selling crops genetically engineered to resist glyphosate in the 1990s, the herbicide’s use soared. Farmers who once juggled an array of herbicides — what killed weeds in a cotton field might kill cornstalks in a cornfield — suddenly had a single herbicide that could be applied to almost all major crops without harming them.
There were even environmental benefits: Farmers relied less on other, more dangerous weed killers. And they abandoned techniques like tilling that discouraged weed growth, but hastened erosion and moisture loss.
But constantly dousing crops in glyphosate exacted a price. Weeds with glyphosate-resisting genetic mutations appeared faster and more often — 16 types of weed so far in the United States. A 2012 survey concluded that glyphosate-resistant weeds had infested enough acreage of American farmland to cover a plot nearly as big as Oregon, and that the total infestation had grown 51 percent in one year. Glyphosate-resistant palmers first surfaced in 2005, in a field in Macon County, Ga. Nine years later, they are in at least 24 states.
“There’s no substantive argument about whether the problem’s gotten far worse in this era of genetically resistant crops,” said Charles Benbrook, a professor and pesticide expert at Washington State University. “The advent of herbicide-tolerant crops made it possible for farmers to load up so much herbicide on one crop that it was inevitable that it would develop resistance.”
Now farmers are going back to older techniques to control weeds, using more varieties of herbicides, resuming tilling — and worse.
Palmer amaranth is the prime example. Consider the cotton fields that blanket many Southern farms: Without glyphosate, almost no herbicides can kill the weed without also damaging cotton plants. Some farmers have mowed their crops to keep palmer seeds from maturing. In 2009, Georgia spent $11 million to send laborers into a million acres of cotton fields to pull palmers out by hand.
For many farmers, including the Harpers, manual labor has become a last resort in the battle against carelessweed.
“I consider myself a Roundup baby, and it was great,” Scott Harper said. “You didn’t have to think about anything. And now we get this weed that flips everything on its head.”
The Harpers’ 2,500-acre soybean crop is an object lesson in palmer’s adaptability and how far farmers must go just to keep it in check.
Palmer amaranths seem as if they were designed by nature to outwit herbicides and farmers. Unlike many weeds, it has male and female versions, increasing genetic diversity — and the chances of a herbicide-resistant mutation — in each new seed. And each plant is astonishingly prolific, producing up to 200,000 seeds in an average field, said Dave Mortensen, a professor of weed and plant ecology at Pennsylvania State University.
“If one out of millions or billions of seeds contains a unique trait that confers resistance to herbicide,” he said, “it doesn’t take long when a plant is that fecund for it to become the dominant gene.”
William G. Johnson, a Purdue University professor of botany and plant pathology, said the weed probably arrived at the Harpers’ farm in typical fashion: in manure, purchased as fertilizer, from cows that ate cottonseed — and, inadvertently, palmer seeds.
The Harpers initially mistook the weed for waterhemp, a close relative. Before they learned otherwise, combines had already harvested fields containing mature palmer seed pods and had spread the seed far and wide.
A glyphosate-resistant palmer is a mighty beast indeed. Its seeds can germinate any time during the growing season, so herbicide sprayed in April is useless against a palmer that appears in July. Once sprouted, palmer amaranth can grow more than two inches a day. Once it exceeds four inches, even herbicides for which it lacks resistance begin to lose their effectiveness.
The Harpers have kept palmers at bay in their 5,500 acres of corn by spraying dicamba, a weed killer that is benign to corn. Soybeans are a different matter.
Last year, the Harpers sprayed palmer-infested fields several times with glyphosate and two other herbicides, pushing herbicide costs to $80 an acre from $15. About eight in 10 palmers died. The rest wilted for a couple of weeks, then resumed growing.
This year, they are trying a different chemical cocktail that raises herbicide costs only to $45 an acre. Their big gun, a herbicide that blocks palmers from synthesizing amino acids, was sprayed on July 3, the first of two applications allowed each summer.
“I came back from the Fourth of July weekend, and they looked dead,” Mr. Harper said. “I said, ‘I think we smoked ’em.’ My dad says, ‘Awesome.’ ” He paused. “Ten days later, there’s green coming all over them again.”
Should the second herbicide application fail, Mr. Harper said, he is unsure what to do next.
More broadly, experts in glyphosate’s travails — farmers, scientists, regulators, the herbicide industry, environmentalists — feel much the same way.
The industry has readied a new barrage of genetically engineered crops that tolerate other weed killers. The Environmental Protection Agency is set to approve plans by Dow AgroSciences to sell soybean seeds that tolerate not only glyphosate, but a much older herbicide, 2,4-D, and a third widely used herbicide, glufosinate. Monsanto hopes to market soybeans and cotton next year that resist dicamba.
Dr. Mortensen and others say the companies are simply repeating the history that made palmers resistant to glyphosate. He says natural solutions, like planting what are known as cover crops that keep light from reaching germinating palmers, may cost more but are also effective.
Mr. Harper said he believes Dr. Mortensen is right. He also said he cannot wait for Monsanto and Dow to begin hawking their new soybeans anyway.

“I’m not stupid. I know you can only ride a pony so far,” he said. “It’ll probably take another 10 years before palmer becomes a real big problem again. But that just brought me 10 years I didn’t have.”