From Ruth

FAILURE TO YIELD

EVALUATING THE PERFORMANCE OF GENETICALLY ENGINEERED CROPS

Union of Concerned Scientists

April 14, 2009

http://ucsusa.org/food_and_agriculture/science_and_impacts/science/failure-to-yield.html

For years the biotechnology industry has trumpeted that it will feed the

world, promising that its genetically engineered crops will produce higher

yields.

That promise has proven to be empty, according to Failure to Yield, a report

by UCS expert Doug Gurian-Sherman released in March 2009

. Despite 20 years of research and 13 years of

commercialization, genetic engineering has failed to significantly increase

U.S. crop yields.

Failure to Yield is the first report to closely evaluate the overall effect

genetic engineering has had on crop yields in relation to other agricultural

technologies. It reviewed two dozen academic studies of corn and soybeans,

the two primary genetically engineered food and feed crops grown in the

United States. Based on those studies, the UCS report concluded that

genetically engineering herbicide-tolerant soybeans and herbicide-tolerant

corn has not increased yields. Insect-resistant corn, meanwhile, has

improved yields only marginally. The increase in yields for both crops over

the last 13 years, the report found, was largely due to traditional breeding

or improvements in agricultural practices.

The UCS report comes at a time when food price spikes and localized

shortages worldwide have prompted calls to boost agricultural productivity,

or yield -- the amount of a crop produced per unit of land over a specified

amount of time. Biotechnology companies maintain that genetic engineering is

essential to meeting this goal. Monsanto, for example, is currently running

an advertising campaign warning of an exploding world population and

claiming that its ³advanced seedsŠ significantly increase crop yieldsŠ² The

UCS report debunks that claim, concluding that genetic engineering is

unlikely to play a significant role in increasing food production in the

foreseeable future.

The biotechnology industry has been promising better yields since the

mid-1990s, but Failure to Yield documents that the industry has been

carrying out gene field trials to increase yields for 20 years without

significant results.

Failure to Yield makes a critical distinction between potential -- or

intrinsic -- yield and operational yield, concepts that are often conflated

by the industry and misunderstood by others. Intrinsic yield refers to a

crop¹s ultimate production potential under the best possible conditions.

Operational yield refers to production levels after losses due to pests,

drought and other environmental factors.

The study reviewed the intrinsic and operational yield achievements of the

three most common genetically altered food and feed crops in the United

States: herbicide-tolerant soybeans, herbicide-tolerant corn, and

insect-resistant corn (known as Bt corn, after the bacterium Bacillus

thuringiensis, whose genes enable the corn to resist several kinds of

insects).

Herbicide-tolerant soybeans, herbicide-tolerant corn, and Bt corn have

failed to increase intrinsic yields, the report found. Herbicide- tolerant

soybeans and herbicide-tolerant corn also have failed to increase

operational yields, compared with conventional methods.

Meanwhile, the report found that Bt corn likely provides a marginal

operational yield advantage of 3 to 4 percent over typical conventional

practices. Since Bt corn became commercially available in 1996, its yield

advantage averages out to a 0.2 to 0.3 percent yield increase per year. To

put that figure in context, overall U.S. corn yields over the last several

decades have annually averaged an increase of approximately one percent,

which is considerably more than what Bt traits have provided.

In addition to evaluating genetic engineering¹s record, Failure to Yield

considers the technology¹s potential role in increasing food production over

the next few decades. The report does not discount the possibility of

genetic engineering eventually contributing to increase crop yields. It

does, however, suggest that it makes little sense to support genetic

engineering at the expense of technologies that have proven to

substantially increase yields, especially in many developing countries. In

addition, recent studies have shown that organic and similar farming methods

that minimize the use of pesticides and synthetic fertilizers can more than

double crop yields at little cost to poor farmers in such developing regions

as Sub-Saharan Africa.

The report recommends that the U.S. Department of Agriculture, state

agricultural agencies, and universities increase research and development

for proven approaches to boost crop yields. Those approaches should include

modern conventional plant breeding methods, sustainable and organic farming,

and other sophisticated farming practices that do not require farmers to pay

significant upfront costs. The report also recommends that U.S. food aid

organizations make these more promising and affordable alternatives

available to farmers in developing countries.

³If we are going to make headway in combating hunger due to overpopulation

and climate change, we will need to increase crop yields,² said

Gurian-Sherman. ³Traditional breeding outperforms genetic engineering hands

down.²

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Common Questions And Answers About Failure To Yield:

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