Making the Case for Pesticide Use in Today's Cotton Fields

Few topics of discussion (with the exception perhaps of the current U.S. elections) receive as much debate these days than how cotton should be farmed and harvested. The lowly gossypium plant, which is cultivated across the world, was once a remarkably hard crop to farm and harvest. The stories of African American cotton pickers’ bloody hands and endemic poverty during the early and mid-1900s became a symbol of the injustices that were equated with an industry that had at that time, neither the technology nor the means to meet the needs of growing demand.

While the mechanical cotton picker of the 1940s addressed some human rights concerns, it has since been replaced today with automated machines that can harvest as much as 190,000 pounds a day.

The introduction of genetic modification to U.S. cotton farming in the 1990s further transformed the conventional cotton industry. Studies have found that genetic modification of cotton seeds not only increased cotton production, but reduced the need for insecticides and some other forms of pesticides in the field. In the U.S., technology has kept up with these changes, creating increasingly faster ways for cotton to be harvested from the field. Even though the U.S. is no longer the largest producer of conventional cotton (third, compared to China and India), it reaps tremendous benefit from the newer innovations that have become a mainstay of cotton production. According to Cotton Incorporated, the conventional U.S. cotton industry (that is, cotton not grown or produced organically), contributes to as much as $100 billion in revenues to affiliated industries.

But those advances continue to spur debate about the best – and safest – way to generate the world’s demand for this much-needed apparel product. Does GM cotton come with secondary health risks? Is GM cotton safe for the environment? Are the pesticides that end up being used with the process risky? Do the benefits of conventional cotton outweigh the concerns that are prompted by pesticide use?

TriplePundit writers have written a fair amount on organic cotton topics, from the nuts and bolts of the global organic cotton industry to the strides  that the organic garment industry has made in recent years. We felt it was time, therefore, to take a deeper look at the processes that are used in conventional cotton production and the points raised by that industry about the benefits of transgenetic cotton farming.

To get the industry’s input on this question, we spoke to Cotton Inc’s Director of Agricultural Research in Entomology, Ryan Kurtz.  Kurtz’s area of expertise is insect resistance management in genetically engineered corn and cotton. Formerly the global lead for traits insect resistance management at Syngenta, Kurtz specializes in North American Bt trait cotton production, a cotton engineered to fight the infamous boll weevil, among other pests. Most of the information below therefore focuses on U.S. cotton production.

Conventional cotton: Not all pesticides are created equally

To really address the debate over conventional cotton production, said Kurtz, it’s necessary to recognize that not all kinds of pesticides can be lumped together. We may think of insecticides, herbicides and fungicides as ‘pesticides’ but in truth, they are vastly different from each other in how they are applied and what they do.

“I think it is always important to be precise at any way you are describing things. Pesticides is a large bucket area. I think people do tend to think of insects more as “pests” than weeds and funguses, because they can relate more to it,” explained Kurtz.

The distinction of insecticide from other types of pesticides is critical, said Kurt, if you want to determine whether GM technology has made a difference in making cotton production safer and whether it should have a role in cotton production. According to information we received from Cotton Inc, GM production has dramatically lowered the demand for insecticide on cotton farms. And that in turn, has made cotton production safer.

But its real coup d’etat may have come in the boost it gave to production yields when it effectively made GM cotton immune to one of the South’s most destructive pests: the boll weevil.

Nicknamed ïn 1903 as America’s “wave of evil,” the tiny insect caused widespread destruction of the country’s cotton yields until insecticides came on the market. In the 1970s, boll weevil eradication began in earnest in a multi-state effort. The evil weevil has largely been eradicated at this point thanks to a systemic approach to strategic insecticide use.   Cotton Inc points out that some 20 years after its introduction in the U.S. South, the impact of transgenic farming can be found in the number of applications of insecticide still used in the U.S. According to data supplied by the organization, "U.S. cotton growers applied insecticide an average of 1.96 times over the course of the season – less than twice.”

Kurtz said that those low numbers are due to farming methods that capitalize on of one of Nature's more ingenious inventions: a bacteria that lives in the soil and is lethal to many insects. By figuring out how to genetically introduce the bacillus thuringiensis (Bt) gene into plants (cotton in this case), scientists were able to make the plant resistant to the bollworm and other destructive insects.

"Through a natural process called agrobacterium mediated transfer (AMT), they figured out how to get the gene from that Bt bacteria that produces the insecticidal protein to put that gene into a cotton plant. So now, instead of having to rely on the bacteria to make the protein that kills the insect, the plant makes the protein that kills the insects. "

GM cotton: the hurdles that still remain

As effective as transgenic cotton farming has been in reducing insect infestations of cotton, however, there have still been some challenges to overcome. The first, note scientists at the Aroian Lab at the University of San Diego, is figuring out just how Bt does what it does.

"[With] 50 [years] of use, you'd think we've got everything figured out about Bt. But the truth is, we don't know much. Most importantly, we don't know how it works," notes the lab in its blog post, bacillus thuringiensis. That question is important because recent reports of insect resistance to the Bt trait have led scientists to realize that they don't know everything about the trait, or how to ensure that more insects don't develop immunity. The Aroian Lab points out that this problem isn't limited to GM farming, either, so it's not a specific failing of GM technology. "For every single synthetic pesticide that is in use today, there are species of insects that are resistant to it." Unlocking how Bt acts could answer why some insects are immune to its toxin.

But immunity isn't the only problem that has surfaced regarding Bt GM farming, says Melody Meyer, who serves as the vice president to Policy and Industry Relations for United Natural Foods Incorporated and as the executive director to the UNFI Foundation. As so often happens in Nature with unintended outcomes, the dramatic reduction in insects has added consequences.

"It may have reduced insecticide use but not herbicides," said Meyer. In fact several studies in the last decade have confirmed that the use of GM technology hasn't reduced herbicide use. It has increased it.

And that's where farmers have found the greatest proof to the maxim, "to every front there's a back." For every organism that may be reduced through scientific farming methods, there may be another that can capitalize on it. Since 2004, farmers have been finding "superweeds" that have acquired an intolerance to the herbicide Roundup (glyphosate).  Reports of Roundup-intolerant weeds such as amaranth have been known to destroy thousands of acres of cotton crops.

Recent studies on glyphosate toxicity in the environment and the food chain is another issue of debate concerning the methods used to produce conventional cotton. Kurtz said that while some studies have suggested that glyphosate may be a "probable" carcinogen, "there is very little evidence, if any to support that and there has been a long, 30+ year history of safe use in the U.S. Kurtz said the fact that it is considered a "general-use pesticide" is indicative that it is safe. "Most reputable organizations highlighted early on that there is a long history of safe use of glyphosate and the concerns about cancer are unwarranted.

In fact, the debate over this issue has persisted for years, as Kurtz stated. The United Nations Food and Agriculture Organization and the World Health Organization stated in May that it was "unlikely" that the chemical would pose "carcinogenic risk" from exposure through diet. The statement contradicts the International Agency for Research on Cancer, which stated in 2015 that there was a likelihood that the pesticide is carcinogenic. It has stood by its claim, even though two other agencies, the Environmental Protection Agency and the European Food Safety Authority contradict its position. More research is underway.

Cottonseed oil and questions of pesticide residue

Cotton that is manufactured in the U.S. is used not only for clothes but for food. Cottonseed oil has been manufactured from the plant's seed at least since the early 1900s. Today it is  the unsung hero of today's conventional food manufacturing systems due to its shelf stability.

The the two questions commonly raised are how much pesticide residue is left on the fibers and seed after the harvesting? How much residue is in the final product?

"Because of the way cotton is grown and the amount of time that it is in the field, the use of pesticides in cotton [production] is well before the fiber is developed. So you actually can set the goal of using pesticides to protect the plant that produces the fiber. Once the fiber is there, most pesticides aren't applied any more," said Kurtz, who said the organization monitors studies on pesticide residue through its membership in Bremen Cotton Exchange, an economic organization concerned with advancing the global cotton trade. So the fibers that make their way into the apparel supply chain are unlikly to bring pesticide residue with them.

He added that because cotton oil is a food product, the Food and Drug Administration regulates what and when pesticides can be added to the growing plant. "They look at cotton just like it were a vegetable," with a set criteria that limits the use of insecticide and other toxic substances.

Still, there are a considerable number of researchers and activists who question this data. Alliance of Women Scientists and Scholars, for example, maintains that "[conventional] cottonseed oil may be highly contaminated with pesticide residues" and that the cottonseed oil's natural toxin, gossypol, is also a common allergen. [Gossypol] poisoning is common and may be deadly for dairy cows and other livestock." However, the site offers limited data to back up this claim. Gossypol is generally removed during the oil refining process, so what might hurt cows in raw form should be harmless for humans who consume the oil.

While pesticide residues have been found in cottonseed oil in India, it is not clear if those pesticides were applied the same way as in the U.S., where workers must be trained and labeling is enforced by the EPA. And not all studies of pesticide use in India have found residues, either. One study found plenty of examples of residue contamination in fruits and vegetables in India, but none in cotton fibers.

But a University of Missouri newsletter offers the best explaination as to why cottonseed oil manufactured in the U.S."rarely" show residues of pesticides in lab tests. The issue isn't just when the insecticide is applied, but where the cotton grown.

"[Cotton] raised for oil is grown mostly in Iowa, Nebraska, and the Dakotas, not in the South.  The shorter growing season there prevents maturation of the fiber-producing cotton boll," explains the writer. (The USDA offers a more comprhensive list of states where cotton is grown).  This shorter season requires precise control, as Kurtz suggests, so pesticides are applied only up until the boll is about to open. After the cotton is picked and the seed processed into oil, the oil goes through a "deodorizing" stage in which it is subjected to hot steam in a vacuum setting. The cleansing is supposed to remove any residue of insecticide or other unwanted compounds.

Meyer from UNFI suggests however, that with the broad disagreement on this issue, skeptics will continue looking for third-party data to prove that cottonseed oil is completely free of pesticide residue.

Conventional cotton and organic processes

One question we asked Kurtz was why, given the growing interest in organic cotton, conventional cotton industry didn't consider transitioning toward an organic production model. If there was public pushback against GM foods, why not take the steps now to help farmers adopt organic processes.

"I think it is a matter of feasibility," said Kurtz. "Organic production works quite well for certain growers on smaller acreages. The ability to scale that up would just be too expensive because of the cost of labor. Some of the organic practices just prohibit some of the more mechanized means that we are using today  and there just wouldn't be a way to produce enough fiber to meet the demand through organic means. It would just cost too much to produce."

Given the world's increasing dependence on cotton for clothing, food and medical products, it's a perspective that makes sense. With 7 billion people on the planet, and a demand that exceeds that of any other fiber in existence, transitioning from GM methods may seem impractical on the surface.

Meyer agreed that "the demand for organic cotton isn't as high as the total production of cotton worldwide," but she argued that this was largely because "people don't understand the long-term effects to the environment and to society and health in general that this poses down the line. There are unintended consequences that you pay for later," she said.

Data: The final benchmark in cotton production

If there were one lesson to draw from the endless debate over how cotton should be grown and processed, it might be that it is quantifiable research results that tell the true story about pesticide use in cotton production. Is there really widespread insecticide residue in cotton products? Does glyphosate have unintended consequences? Answers to either or both of these questions may in coming years, alter our view of GM produced cotton.But what those answers won't do, is change the impact that conventional cotton production with all of its problems and remarkable concepts, has had on the world as we know it.

Images: Cotton harvest - Flickr/Kimberly Vardeman; Two young cotton pickers, 1937 -Flickr/Kheel Center; Boll weevil on cotton plant - Flickr/USDA; Cotton bud - Flickr/USDA; Cotton field - Flickr/Kimberly Vardeman