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USDA report: genetically engineered crops don't measure up

Glyphosate applications to U.S. corn, soy and cotton and super-weeds
Glyphosate applications to U.S. corn, soy and cotton and super-weeds
Data sources: USDA, Charles Benbrook

The U.S. government seems to be the last to know about, or maybe just the last to admit, the failures of genetically engineered (GE) crops. The U.S. Department of Agriculture (USDA) released their report on Genetically Engineered Crops in the United States last month (February, 2014). It has been said that the USDA has never met a GMO that it didn't like. While the report is whitewashed in favor of GMOs, the USDA finally admitted to a few things the rest of us have known for a while.

The report begins, “Genetically engineered (GE) varieties with pest management traits became commercially available for major crops in 1996. More than 15 years later, adoption of these varieties by U.S. farmers is widespread and U.S. consumers eat many products derived from GE crops—including cornmeal, oils, and sugars—largely unaware that these products were derived from GE crops. Despite the rapid increase in the adoption of corn, soybean, and cotton GE varieties by U.S. farmers, questions persist regarding their economic and environmental impacts, the evolution of weed resistance, and consumer acceptance.” [emphasis added]

The persistent questions probed by the report are:

  1. GE crops do not have higher yield. “Over the first 15 years of commercial use, GE seeds have not been shown to increase yield potentials of the varieties. In fact, the yields of herbicide-tolerant or insect-resistant seeds may be occasionally lower than the yields of conventional varieties...[p. 12] ... The fact that several researchers found no significant differences between the net returns of adopters and nonadopters of HT [herbicide tolerant] crops (particularly HT soybeans) despite the rapid adoption of these crops suggests that many adopters may derive nonmonetary benefits from HT adoption. In particular, weed control for HT soybeans may be simpler, freeing up management time for leisure, enterprise growth, or off-farm income-generating activities [p. 22].” Despite this, over 70% of farmers believe GE crops increase yield and that is the reason they gave for planting them. [Fig. 7] The biotechnology companies probably hope that farmers don't read USDA reports.

Thanks USDA, but we have known that since 2009 from the report, Failure to Yield, by Dr. Doug Gurian-Sherman.

  1. GE crops do not reduce pesticide use. Insecticide use has decreased since the introduction of Bt crops, “However, there are some indications that insect resistance is developing to some Bt traits in some areas [summary, emphasis added].” But insecticide use has gone down even more dramatically in non-GE corn crops [Fig. 13], “suggest[ing] that insect infestation levels on corn were lower in recent years than in earlier years [p. 24].” The authors attribute this to the widespread adoption of Bt corn.

It seems the authors were extremely reluctant to admit that the insects are developing a resistance to the Bt crops. Within seven years of the first Bt crops, the bollworm started to become resistant to Bt cotton and the corn rootworm to the Bt corn. The solution, as always, was to stack traits and add more of the Bt traits (Cry1Ac and Cry2Ab for cotton; Cry3Bb1, mCry3A & Cry34/35Ab1 for corn). But the worms continue to develop resistance to the toxins one by one in spite of crop buffer zones. Recommendations are crop rotation and more insecticide use.

Herbicide use declined in the first few years, then has steadily increased. “Herbicide use on corn by HT adopters increased from around 1.5 pounds per planted acre in both 2001 and 2005 to more than 2.0 pounds per planted acre in 2010, whereas herbicide use by nonadopters did not change much [p. 24].” “Herbicide toxicity may soon be negatively affected (compared to glyphosate) by the introduction (estimated for 2014) of crops tolerant to the herbicides dicamba and 2,4-D [p. 25].”

Dr. Charles Benbrook told us that in his 2012 paper, Impacts of genetically engineered crops on pesticide use in the U.S. -- the first sixteen years.

  1. Herbicide use [Roundup] has resulted in glyphosate-resistant super-weeds. “HT adoption likely reduced herbicide use initially, but herbicide resistance among weed populations may have induced farmers to raise application rates in recent years, thus offsetting some of the economic and environmental advantages of HT corn adoption regarding herbicide use [p. 24, emphasis added].” The industry response is to stack more GE traits making crops tolerant to more herbicides. “Herbicide toxicity may soon be negatively affected (compared to glyphosate) by the introduction (estimated for 2014) of crops tolerant to the herbicides dicamba and 2,4-D [p. 25].”

Dr. Benbrook told us that, too. What, then are the benefits of GE crops?

The USDA still maintains that glyphosate is relatively benign. Benign relative to dicamba and 2,4-D anyway.

“Despite the mixed but relatively minor effect HT crop adoption has had on overall herbicide usage, most researchers agree* that the main effect of HT crop adoption is the substitution of glyphosate for more traditional herbicides. Because glyphosate is significantly less toxic and less persistent than traditional herbicides the net impact of HT crop adoption is an improvement in environmental quality and a reduction in the health risks associated with herbicide use (even if there are slight increases in the total pounds of herbicide applied) [pp. 24-25].”

That's their story and they're sticking to it. Until the next report.*

* In a footnote, the authors admitted that not all scientists agree that glyphosate is less toxic and less persistent.