Keep up with the latest news and comment on genetically modified foods          

Featured Articles on GMO issues

GM crop technology backfires: study

1.Pesticide Use Rises as Herbicide-resistant Weeds Undermine Performance of Major GE Crops, New WSU Study Shows – Washington State University
2.Pesticide use ramping up as GMO crop technology backfires: study – Reuters

NOTE: The Washington State University press release (item 1) has a link to a three-page, lay person summary of major findings. There is a link, as well, to the full paper on the journal's website. 

This paper has a lot more than just Benbook's GM crop-pesticide findings. His 2,4-D GM corn projections are also in this paper; the estimates of the pounds of Bt proteins produced per acre, relative to insecticide pounds displaced is in the paper, and somewhat surprising; and, the argument over whether Bt corn is compatible, as sometimes claimed, with Integrated Pest Management (IPM) is laid out.
–-
–-
1.Pesticide Use Rises as Herbicide-resistant Weeds Undermine Performance of Major GE Crops, New WSU Study Shows
Washington State University, 1 October 2012
http://cahnrsnews.wsu.edu/2012/10/01/pesticide-use-rises-as-herbicide-resistant-weeds-undermine-performance-of-major-ge-crops-new-wsu-study-shows/

PULLMAN, Wash. A study published this week by Washington State University research professor Charles Benbrook finds that the use of herbicides in the production of three genetically modified herbicide-tolerant crops cotton, soybeans and corn has actually increased. This counterintuitive finding is based on an exhaustive analysis of publicly available data from the U.S. Department of Agriculture’s National Agriculture Statistics Service. Benbrook’s analysis is the first peer-reviewed, published estimate of the impacts of genetically engineered (GE) herbicide-resistant (HT) crops on pesticide use. Dr. Charles Benbrook, research professor, WSU Center for Sustaining Agriculture and Natural Resources. Photo courtesy Washington State University. Click image to download hi-resolution version.

Dr. Charles Benbrook, research professor, WSU Center for Sustaining Agriculture and Natural Resources. Photo courtesy Washington State University. Click image to download hi-resolution version.

In the study, which appeared in the the open-access, peer-reviewed journal “Environmental Sciences Europe,” Benbrook writes that the emergence and spread of glyphosate-resistant weeds is strongly correlated with the upward trajectory in herbicide use. Marketed as Roundup and other trade names, glyphosate is a broad-spectrum systemic herbicide used to kill weeds. Approximately 95 percent of soybean and cotton acres, and over 85 percent of corn, are planted to varieties genetically modified to be herbicide resistant.

"Resistant weeds have become a major problem for many farmers reliant on GE crops, and are now driving up the volume of herbicide needed each year by about 25 percent," Benbrook said. [Clarification from Chuck Benbrook received 7 Oct 2012: "Farmers planting GM RR crops in 2011 sprayed 25% more herbicide than they
would have, had they planted non-GM varieties."]

The annual increase in the herbicides required to deal with tougher-to-control weeds on cropland planted to GE cultivars has grown from 1.5 million pounds in 1999 to about 90 million pounds in 2011.

Herbicide-tolerant crops worked extremely well in the first few years of use, Benbrook’s analysis shows, but over-reliance may have led to shifts in weed communities and the spread of resistant weeds that force farmers to increase herbicide application rates (especially glyphosate), spray more often, and add new herbicides that work through an alternate mode of action into their spray programs.

A detailed summary of the study's major findings, along with important definitions of terms used in the study, are available online at http://bit.ly/esebenbrookmajor. Benbrook's study, "Impacts of genetically engineered crops on pesticide use in the U.S. the first sixteen years," is available online at http://bit.ly/esebenbrook2012.
–-
–-
2.Pesticide use ramping up as GMO crop technology backfires: study
Reuters, 2 October 2012
http://uk.reuters.com/article/2012/10/02/us-usa-study-pesticides-idUKBRE89100X20121002

U.S. farmers are using more hazardous pesticides to fight weeds and insects due largely to heavy adoption of genetically modified crop technologies that are sparking a rise of "superweeds" and hard-to-kill insects, according to a newly released study.

Genetically engineered crops have led to an increase in overall pesticide use, by 404 million pounds from the time they were introduced in 1996 through 2011, according to the report by Charles Benbrook, a research professor at the Center for Sustaining Agriculture and Natural Resources at Washington State University.

Of that total, herbicide use increased over the 16-year period by 527 million pounds while insecticide use decreased by 123 million pounds.

Benbrook's paper – published in the peer-reviewed journal Environmental Sciences Europe over the weekend and announced on Monday – undermines the value of both herbicide-tolerant crops and insect-protected crops, which were aimed at making it easier for farmers to kill weeds in their fields and protect crops from harmful pests, said Benbrook.

Herbicide-tolerant crops were the first genetically modified crops introduced to world, rolled out by Monsanto Co. in 1996, first in "Roundup Ready" soybeans and then in corn, cotton and other crops. Roundup Ready crops are engineered through transgenic modification to tolerate dousings of Monsanto's Roundup herbicide.

The crops were a hit with farmers who found they could easily kill weed populations without damaging their crops. But in recent years, more than two dozen weed species have become resistant to Roundup's chief ingredient glyphosate, causing farmers to use increasing amounts both of glyphosate and other weedkilling chemicals to try to control the so-called "superweeds."

"Resistant weeds have become a major problem for many farmers reliant on GE crops, and are now driving up the volume of herbicide needed each year by about 25 percent," Benbrook said.

Monsanto officials had no immediate comment.

"We're looking at this. Our experts haven't been able to access the supporting data as yet," said Monsanto spokesman Thomas Helscher.

Benbrook said the annual increase in the herbicides required to deal with tougher-to-control weeds on cropland planted to genetically modified crops has grown from 1.5 million pounds in 1999 to about 90 million pounds in 2011.

Similarly, the introduction of "Bt" corn and cotton crops engineered to be toxic to certain insects is triggering the rise of insects resistant to the crop toxin, according to Benbrook.

Insecticide use did drop substantially – 28 percent from 1996 to 2011 – but is now on the rise, he said.

"The relatively recent emergence and spread of insect populations resistant to the Bt toxins expressed in Bt corn and cotton has started to increase insecticide use, and will continue to do so," he said.

Herbicide-tolerant and Bt-transgenic crops now dominate U.S. agriculture, accounting for about one in every two acres of harvested cropland, and around 95 percent of soybean and cotton acres, and over 85 percent of corn acres.

"Things are getting worse, fast," said Benbrook in an interview. "In order to deal with rapidly spreading 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."

(Reporting By Carey Gillam; Editing by Ken Wills)