1.Failure to Yield Turns on Biotech Spin Machines
2.More Response to Criticism of Failure to Yield

NOTE: Two superb responses to criticisms (from the usual suspects) of the recent report on GM food crops in the USA, Failure to Yield. 
http://www.ucsusa.org/food_and_agriculture/science_and_impacts/science/failure-t o-yield.html

They come from The Real Scoop, a new online column from the Union of Concerned Scientists on the science- and policy-related aspects of industrial agriculture, genetic engineering, and sustainable agriculture.http://ucsusa.org/food_and_agriculture/science_and_impacts/science/the-real-scoo p/the-real-scoop.html 

The responses are by Dr Doug Gurian-Sherman, a former EPA biotech specialist and the Senior Scientist at UCS who authored Failure to Yield.
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1.Failure to Yield Turns on Biotech Spin Machines
Doug Gurian-Sherman
The Real Scoop, April 29 2009
http://www.ucsusa.org/food_and_agriculture/science_and_impacts/science/the-real- scoop/2009-entries/TRS042909.html

On April 14, Union of Concerned Scientists released a new report, Failure to Yield, which analyses the contribution of genetically engineered traits to increased food and feed crop yields in the United States. The report was motivated by questions raised by the recent food crisis about the ability of the human population to produce enough food, and by ongoing claims that genetic engineering has increased yields and will be vitally important for doing so in coming years. 

Since the launch of Failure to Yield, several comments complained that the report does not include studies from the developing world. In essence, they claim that the report misses important parts of the picture.

I think these comments are off the mark. By criticizing what is not in the report, they divert attention from its core finding that a solid body of research shows that despite decades of trying, genetically engineered (GE) traits in the United States contribute only marginally to increased yields, while at the same time, other means of agricultural innovation have shown great success at increasing crop yields.

Nevertheless the comments raise important issues that are worth additional discussion.

Critique #1: Failure to Yield does not include yield data from GE crops in developing countries

This is an important point, because although the report is about the impact of GE on the yield of food and feed crops in the United States, the context of the report is the coming global food crisis, and several recommendations concern agriculture policy toward developing counties.

There are several reasons why we focus on data from the United States, why these data have relevance for other parts of the world, and why data about GE crops in developing countries have some important limitations and therefore may not be as useful as would first appear. 

To begin, our question was not whether GE crops exhibit increased yields, but rather whether any observed yield increases were attributable to the GE traits. To answer that question we needed to find research that isolated the impacts of GE traits from the other factors that may increase yield. That research is mostly found in the US, where yields have been extensively studied and where crops with GE traits have been compared to crops grown in various ways. 

By contrast, there are relatively few yield studies done on GE food crops in other countries and for the most part those studies do not isolate GE traits, but simply look at yields from GE crops. Some of these studies report increased yields, but fail to tease out the contribution due to fertilizers, irrigation, and other factors which can be dramatic on resource-poor farms. Failure to Yield analyzes studies that do isolate the GE traits and shows that they have contributed only marginally at best to increased crop yields, much less than other agricultural methods (collectively). This comparative aspect of the report is largely ignored by critics, despite being an important part of the analysis as discussed below.

Critique #2: The US yield studies are not relevant to developing country agriculture.

Increasing yields of food will be critical for avoid serious food shortages in the future. Understanding which agricultural methods or technologies have the capacity to improve yield is essential to making scientifically grounded recommendations on agricultural technologies and practices for the developing world keeping in mind, of course, that other factors including differences in climate and culture will influence adoption.

Since Failure to Yield demonstrates that GE traits are not key to increasing yield, it makes little sense to promote GE crops to developing countries for that purpose. It makes more sense to offer primarily those methods--traditional breeding and agricultural system improvements””that account for most yield increases. There is every reason to believe these methods will work in developing counties, especially in those countries where increased food yields are most needed. A recent comprehensive United Nations report shows that organic and similar methods more than double yield in Africa -considerably more than GE crops. 
http://www.unctad.org/en/docs/ditcted200715_en.pdf
These other methods also have the advantage of being inexpensive compared to the cost of GE seed in many places (e.g. Indian or Chinese Bt cotton).

Critique # 3. If GE traits sometimes increase yields, why not just promote them along with other more promising methods? 

If some GE traits can deliver increased yields even if less than for other methods why not go ahead and promote them along with the more promising approaches. Don’t let the best be the enemy of the good, many would argue. This approach ignores the opportunity costs of misguided investments. Overrated GE is depriving more promising and proven methods of adequate research and promotional support. Currently, the US investment in traditional breeding and ecologically-based agriculture is wholly inadequate. If the investment were based on demonstrated results for increasing yield, GE technology would get a much smaller slice of the pie compared to these other more effective methods. 

Investment in agriculture for developing countries is dismally low to begin with. Care should be taken not to waste scarce development resources. GE crops need not be excluded from the mix of technologies available to the developing world if countries chose to adopt them, but it should in no way dominate. Many scientists from around the world agree that ecologically-based methods, infrastructure, and conventional crop breeding should be in the lead.
http://www.agassessment.org/
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2.More Response to Criticism of Failure to Yield
Doug Gurian-Sherman
The Real Scoop, April 30 2009
http://www.ucsusa.org/food_and_agriculture/science_and_impacts/science/the-real- scoop/2009-entries/TRS043009.html

I wrote in my last post about why Failure To Yield didn't include studies on the performance of genetically engineered crops in the developing world. Here are my responses to two other critiques. 

Critique: You should have included GE cotton in your analysis

Failure to Yield was motivated in large part by the "global food crisis" of the past few years. So we wanted to examine the ability of GE to address the challenges for food production given a growing global population, changing consumption patterns, and climate change impacts. For this reason, we decided to look at major GE food or feed crops in the United States, and this means soybeans and corn. We didn't include canola, an oilseed crop, because the acreage devoted to canola, about a million acres, is only 0.6 percent of the acreage devoted to corn and soybeans in 2008.

Cotton was excluded because it is primarily a fiber crop. Cotton seed meal may also be used as animal feed, and the plant itself is used as fodder in some places, but these uses are secondary to fiber production. In other words, we did not look at GE cotton because the report is intended to inform the solution of the global food crisis, not a global clothing crisis.

Critique: The yield of corn [or soybeans] has increased faster since the introduction of GE varieties, and faster than in several European countries that do not grow GE varieties. And therefore GE has been responsible for increasing yields in the United States.

This argument, made by University of Georgia agronomy professor Wayne Parrott in a ten-page critique of Failure to Yield represents an elementary error in scientific reasoning: it attributes causality (as in: GE caused the increased yield) to a mere correlation between the coincidence of the introduction of GE traits and observed yield increases.
http://mulch.cropsoil.uga.edu/~parrottlab/Response%20to%20UCS.pdf

As the eminent late evolutionary biologist Stephen J. Gould wrote in a section of The Mismeasure of Man that is devoted to the problem of mistaking correlation for cause: "The invalid assumption that correlation implies cause is probably among the two or three most serious and common errors of human reasoning." 

In this case the inference that GE traits caused observed increases in yield is unfounded because there are many other factors that could have caused yield changes. 

For example, genomic-based methods (non-GE) of conventional breeding were also coming into widespread use in the 1990s, at the same time as GE. These methods can often cut the time it takes to breed new traits, including yield, in half, which in turn could greatly accelerate the rate of yield increase. 

But to attribute the observed corn yield increases to genomic breeding methods without additional experimental data would be a big mistake””the same mistake made by Parrott. 

In fact, the major reason we wrote Failure to Yield, was to try to tease apart the contributions of various factors contributing to yield. Failure to Yield sought out the controlled, published, field experiments that could be used to assess the contribution of GE traits to the yield of GE soybeans and corn in the United States apart from other factors. This approach allows us to subtract the GE yield contribution from U.S. Department of Agriculture data on yields for these crops over time, providing an estimate of the contribution of conventional breeding and improvements other than the addition of transgenes to the yield increases of these crops.

Parrott's critique of Failure to Yield contains other factual errors and errors of reasoning that I will address in my next entry.