1.How GMOs Unleashed a Pesticide Gusher – Tom Philpott
2.Hard lessons emerge from new study on the impacts of GM crops on pesticide use – Chuck Benbrook
RESOURCES: Benbrook's new paper
Washington State University press release
Summary highlighting the major findings.
1.How GMOs Unleashed a Pesticide Gusher
Mother Jones, October 3 2012
Now, biotech industry defenders might counter that the surge in herbicide use is balanced by the other main product offered by the industry: seeds engineered to contain the toxic-to-insects gene found in Bacillus thuringiensis (Bt), a naturally occurring bacterial pesticide. The pitch is this: Rather having to spray corn and cotton with insecticides, plant our Bt seeds, and your insect problems are taken care of.
Benbrook found that the Bt trait indeed led to a reduction in insecticide use of 123 million pounds between 1996 and 2011. But that figure is dwarfed by the 527 million pound, GMO-driven increase in herbicide use over the same period. In other words, GMOs have added more than four pounds of herbicides to US farm fields for every pound of insecticide they've taken away. Overall, Benbrook found, GMOs have lead to a net increase in pesticide use (meaning herbicides plus insecticides) of 404 million pounds, a 7 percent gain.
And just as weeds developed resistance to year-after-year applications of Roundup, corn's number-one insect pest, the rootworm, is quickly evolving to be able to withstand Bt-engineered corn, as I've reported before. Benbrook told me that in areas of the Midwest where farmers have been planting Bt corn year after yearan increasingly popular practice, since the explosion in ethanol production that started in 2006ag university extension experts are suggesting that farmers spray other insecticides to supplement the failing Bt trait in their corn. "The whole of this technology was to make it possible not have to spray these corn insecticides, and now we have to spray them again to bail out this technology," Benbrook told me.
The chemical war against pests will likely get yet another boost from the failure of Roundup. As I've reported before, GMO seed giants Monsanto and Dow are preparing to roll out seeds designed to resist both Roundup and older herbicides including 2,4-D, the less toxic half of the formulation that made up the infamous Vietnam War defoliant Agent Orange. The industry insists that weeds won't develop resistance to the new products. But last year, a group of Penn State weed scientists published a paper warning that the new products are "likely to increase the severity of resistant weeds." Indeed, 2,4-D-resistant weeds have already been documented in Nebraska.
In his paper, Benbrook created a model for how a 2,4-D-resistant corn product, if released in 2013, would affect 2,4-D use. One of the actual benefits of Roundup Ready technology is that it has until recently made 2,4-D almost obsosleteits use on corn crops went from 4.4 million pounds in 1995 to 2.4 million in 2000. It hovered at that level for a while before jumping to 3.3 million pounds in 2010, as farmers increasingly resorted to it to attack Roundup-resistant weeds. If 2,4-D resistant corn is widely adopted, Benbrook projects, making what he calls "conservative" assumptions, 2,4-D use will hit 103.4 millon pounds on corn fields per year by 2019. For years, proponents of genetically modified crops have hailed them as a critical tool for weaning farmers from reliance on toxic pesticides. On its website, the GMO-seed-and-agrichemical giant Monsanto makes the green case for its its Roundup Ready crops, engineered to withstand the company's own blockbuster herbicide, Roundup:
"Roundup agricultural herbicides and other products are used to sustainably an [sic] effectively control weeds on the farm. Their use on Roundup Ready crops has allowed farmers to conserve fuel, reduce tillage and decrease the overall use of herbicides." [Emphasis added.]
But in a just-released paper published in the peer-reviewed Environmental Sciences Europe, Chuck Benbrook, research professor at Washington State University's Center for Sustaining Agriculture and Natural Resources, shreds that claim. He found that Monsanto's Roundup Ready technology, which dominates corn, soy, and cotton farming, has called forth a veritable monsoon of herbicides, both in terms of higher application rates for Roundup, and, in recent years, growing use of other, more-toxic herbicides.
Benbrook found that overall, GMO technology drove up herbicide use by 527 million pounds, or about 11 percent, between 1996 (when Roundup Ready crops first hit farm fields) and 2011. But it gets worse. [CUT: Benbrook shows that] For several years, the Roundup Ready trait actually did meet Monsanto's promise of decreasing overall herbicide useherbicide use dropped by about 2 percent between 1996 and 1999, Benbrook told me in an interview. But then weeds started to develop resistance to Roundup, pushing farmers to apply higher per-acre rates. In 2002, farmers using Roundup Ready soybeans jacked up their Roundup application rates by 21 percent, triggering a 19 million overall increase in Roundup use.
Since then, an herbicide gusher has been uncorked. Between 2009 and 2010 alone, herbicide use jumped 24 percent, Benbrook told me. What happened? By that time, "in all three crops [corn, soy, and cotton], resistant weeds had fully kicked in," Benbrook said, and farmers were responding both by ramping up use of Roundup and resorting to older, more toxic herbicides like 2,4-D.
Overall, Benbrook projects a 30-fold increase in 2,4-D applied between 2000 and 2019. Because 2,4-D is so toxic, the result will not be pretty. Here's Benbrook's study:
"Such a dramatic increase could pose heightened risk of birth defects and other reproductive problems, more severe impacts on aquatic ecosystems, and more frequent instances of off-target movement and damage to nearby crops and plants."
The only question on GMOs and pesticide use Benbrook's paper leaves open is: When will Monsanto correct the absurd claim on its website that its highly lucrative technology has allowed farmers to cut back on herbicides?
2.Hard lessons emerge from new study on the impacts of GE crops on pesticide use
WSU, October 2 2012
I have worked for many years on pesticide use, risks, and regulation, as well as the design, implementation, and benefits of Integrated Pest Management (IPM) systems. Given that all of the commercially significant, first-generation traits in genetically engineered (GE) crops are related to pest management, the real-world impacts of GE crops on pesticide use has always been on my radar screen.
I started tracking the development of herbicide-tolerant technology in the late 1980s during my tenure as the Executive Director of the NAS Board on Agriculture (1984-1990). Even back then, years before the technology’s commercial launch in 1996, weed management experts were expressing concern that glyphosate-tolerant, Roundup Ready (RR) crops could lead to the emergence of resistant weeds.
In the first years of use, RR crops triggered a shift in herbicide selection from several low-dose imidazolinone and sulfonylurea herbicides to a relatively high-dose herbicide, glyphosate. USDA pesticide use data released in the late 1990s clearly reflects such shifts. This is why I was skeptical from the start over claims that GE crops would and were reducing the pounds of herbicide applied on the three major RR crops.
To track changes in pesticide use brought on by GE crops, I started work in 2002 on a model that quantifies GE-crop-pesticide use impacts for both herbicide-tolerant, RR crops and insect-protected, Bt corn and cotton. The model uses publicly accessible USDA data on pesticide use and GE crop adoption. My first report based on model results estimated the impact of GE crops on pesticide use over the first nine years of use (1996-2004), and a 2009 report extended the analysis through the first 13 years. Each analysis documented increasingly high rates of herbicide use on GE acres, compared to acres planted to non-GE cultivars. It is now regrettably clear that the still-common claim that GE crops are reducing herbicide and overall pesticide use is no longer true.
My model and basic findings through the first 16 years of commercial use have now been published in the peer-reviewed, open access journal Environmental Sciences Europe. I chose this journal because it has been publishing the major analytical papers from a series of international conferences on the impacts of GE crops on large spatial scales. This June in Bremen, Germany, I attended the third conference in this series and presented the preliminary results of my 16-year analysis. Another advantage this journal provides free, online access to papers, facilitating the rapid dissemination of results.
The paper is available online, as is a WSU press release announcing its publication. Because the paper is lengthy and technical, I prepared a short document that highlights the major findings.
Limited, publicly accessible data make the job of quantifying the impact of GE crops on pesticide use much more complicated than it needs to be. When the USDA’s National Agricultural Statistics Service (NASS) surveys pesticide use on a corn, cotton, or soybean field, it does not ask the growers two simple questions Did you apply these pesticides on land planted to a conventional or GE crop variety? And if GE, which variety?
Budget cuts in USDA have created another hurdle and source of uncertainty. In the 1990s and through around 2005, NASS had ample funds to annually survey pesticide use on these three major crops. But starting around 2006, NASS could afford to cover only a subset of these crops each year. As a result, corn was not surveyed from 2005 until 2010, cotton was surveyed only in 2007 and 2010, and new soybean pesticide use data has not been released since 2006 (it will be next summer). To deal with gaps between NASS surveys, I assume that pesticide use changes in equal, annual increments. Since the last survey and through 2011, the pounds of pesticides applied are extrapolated conservatively, based on recent trends.
Despite these uncertainties, the overall trends in pesticide use on GE crops are clear. Herbicide use is much greater on GE acres compared to conventionally managed acres planted to non-GE cultivars. The spread of resistant weeds has been driving herbicide use up for a decade, and will continue to do so for years.
In order to deal with resistant weeds, farmers are being forced to expand use of older, higher-risk herbicides. To stop corn and cotton insects from developing resistance to Bt, farmers planting Bt crops are being asked to spray the insecticides that Bt corn and cotton were designed to displace.
Without doubt, GE crop technology has profoundly changed corn, cotton, and soybean pest management, but the unintended impact on pesticide use is a harsh reminder that farmers should not put all their eggs in one pest control basket.
Featured Articles on GMO issues
1.How GMOs Unleashed a Pesticide Gusher – Tom Philpott