U.S. Pesticide Use: Back To The Future

pesticides1Vegetation growing taller that six feet tall with the width of a baseball bat and rootworms happily grazing away at corn roots?! No, it’s not a remake of Little Shop of Horror but the grim agricultural conditions faced by many farmers coping with glyphosate and Bt resistance.

“Palmer [Amaranth] is best described as ‘Satan.’ That gives you an idea about how bad it is,” recently said Aaron Hager, a weed scientist at the University of Illinois, while describing the scope of resistance problem in an interview with Delta Farm Press.  According to Hager, glyphosate resistant Palmer Amaranth, a pigweed, is the most problematic resistant weed species in Arkansas. In Illinois, glyphosate resistant waterhemp has been a growing problem where its presence is pronounced in many counties, and, Hager indicated, it may be beyond chemical solutions.

Glyphosate resistant weeds were practically unknown before the introduction of RoundUp Ready crops in 1996, noted Washington State University’s Charles Benbrook in his 2012 study which evaluated the impacts of genetically engineered crops on pesticide use in the U.S. in the first sixteen years. The industry worked hard to downplay the possibility of resistance. “In the mid-1990s, as the first glyphosate-resistant crops were moving toward commercialization and gaining market share, Monsanto scientists wrote or were co-authors on several papers arguing that the evolution of GR weeds was unlikely.”

Less than two decades later, however, we find 24 documented species of weeds resistant to Monsanto’s Roundup.

In his Congressional testimony in 2010, Bill Freese, the Science Policy Analyst for the Center for Food Safety, said that “unregulated use of glyphosate-resistant crop systems has triggered an epidemic of glyphosate-resistant weeds.”  Recent market data shows the extent of this problem.

According to a survey conducted by Stratus Agri-Marketing Inc., 61.2 million acres of U.S. cropland are infested with glyphosate resistant weeds, almost double since 2010. In fact, nearly half of U.S. farms surveyed have glyphosate resistant weeds on their farm in 2012, up from 34% of farmers in 2011. More importantly, the problem is spreading rapidly and is complicated by more farmers having multiple resistant species on the farm. “In 2010 that was just 12% of farms,” detailed the survey, “but two short years later 27% had more than one,” resistant species.

Hager stated in his interview that “the most challenging scenario currently and in the future with our waterhemp is ‘multiple resistance’ – resistance to more than one herbicide class. In Illinois, it’s very, very common that waterhemp isn’t just resistant to glyphosate but also resistant to one, two, or three other herbicide classes.”

He is not alone in seeing the growth of multiple resistance.  In a piece published in BioScience last year, Prof. David A. Mortensen and his team concluded that “weed species resistant to multiple herbicide modes of action are becoming more widespread and diverse.”

Resistance problems are not limited to crops engineered to withstand glyphosate applications. Crops developed with Bacillus thuringiensis (Bt) for insect resistance, much like their herbicide-resistant brethren, are also succumbing to resistance. A recent report found significant damage from rootworms in Illinois fields where biotech corn was planted in rotation following soybeans, a method practiced to deter rootworm problems. Reuters reported that according to the author of the report, Prof. Michael Gray, “[e]vidence gathered from fields in two Illinois counties suggests that pest problems are mounting as the rootworms grow ever more resistant to efforts to fight them, including crop rotation combined with use of the biotech corn.”

Similarly, in late 2011, the U.S. Environmental Protection Agency (EPA) released a memo which identified the failure of Monsanto’s Bt corn to prevent “unexpected” rootworm damage to the corn crop. The EPA stated that at least four states, Iowa, Illinois, Minnesota, and Nebraska, are seeing “severe efficacy issues” for Monsanto’s Bt corn.

A recent Food&Water Watch Report on superweeds cited a University of Missouri study showing corn rootworms passing Bt resistance on to offspring and a University of Arizona study which found that, within seven years of introduction of Bt cotton, cotton bollworms developed Bt resistance that they passed on to their offspring.

Furthermore, “[a] 2013 National Academy of Sciences study reported that cotton pests showed ‘significant’ resistance to Bt and this resistance was strengthened by GE crops with multiple insect-resistant traits, as is common with tacked Bt corn and cotton varieties,” states the Food&Water Watch report.

The response to weed and insect resistance from the industry has been a desire to turn back the clock.  A favored solution to the problem the seed and agri-chemical manufacturers — the Big Six – helped to create has been to offer the “next generation” of GE crops that are stacking resistance to more toxic pesticides.  Applications are already pending for new varieties of corn, soybeans and cotton tolerant to 2,4-D and dicamba. Guess who are the primary manufacturers of these pesticides and the seeds engineered to withstand them?!

Resistance on farms forces farmers to go back to more ecologically damaging methods of weed and insect control such as increasing herbicide and insecticide application rates, increasing the use of more toxic pesticides and applying multiple active ingredients in tank mixes, noted Benbrook.  In his study, Benbrook found that, although there was an initial reduction in the use of insecticides following introduction of GE crops, overall pesticide use in the United States increased by an estimated 404 million pounds between 1996 and 2011.

Other more damaging farming methods that are also making a comeback despite industry promise to eliminate them with engineered seeds and chemical formulas including burying weed seeds through soil-eroding deep tillage and labor-intensive manual weeding.

In a sense, the great technological leap forward put farming on an express train back. “We’re back to where we were 20 years ago,” said a farmer in a May 4, 2010 NYT article.

Bill Freese commented recently that, “[i]t’s ironic that supposedly ‘cutting-edge’ biotechnology is taking American agriculture a half-century and more backwards into a more toxic past.”

There are healthier farming alternatives to control the resistance problem, such as agroecology, for example, and we will look to examine them in a follow up article.


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