Do GM Crops Increase Yield?

February 9, 2009

soy in handRecently, there have been a number of claims from anti-biotechnology activists that genetically-modified (GM) crops don’t increase yields. Some have claimed that GM crops actually have lower yields than non-GM crops.

Both claims are simply false.

In agriculture, desirable crop characteristics are known as traits. One of the most important traits is yield. Improving crop yield can be accomplished through both breeding and biotechnology. GM crops generally have higher yields due to both breeding and biotechnology.

Germplasm
Germplasm is the basic genetic information in a seed that influences the growth and development of the plant. For example, germplasm for different varieties of tomatoes may vary in pest and disease resistance, drought tolerance, color, size, yield potential and many other characteristics.

Breeding
Starting long before modern biotechnology, plant breeders have worked to improve germplasm--for example, to develop seeds with the best mix of characteristics to deliver the best yield possible for the soil and climatic conditions where they will be grown.

Today, plant breeders use a mix of both traditional and modern methods to improve plants. Modern methods include marker assisted breeding, which enables breeders to use a blueprint of the genome to select seeds with the most desirable properties. Marker assisted breeding in effect helps speed up the time it takes to do traditional breeding--breeders can better select whether to cross tomato A with tomato B, or C, or D, or E, or F, or …--you get the idea--to get the desired improvement.

Biotechnology
Biotechnology is a more direct approach than breeding since it allows you to incorporate genetic material directly into the germplasm. This allows you to create plants with traits that would be difficult or impossible to achieve through breeding. In some GM crops, the genetic material originates from another species. The most common traits in GM crops are herbicide tolerance (HT) and insect resistance (IR). HT plants contain genetic material from common soil bacteria. IR crops contain genetic material from a bacterium that attacks certain insects.

Yield
Yield can be increased by breeding and through the addition ofGMtraits.
Germplasm improvements from traditional breeding have contributed to modest but steady increases in yield. Marker-assisted breeding has nearly doubled the rate of yield gain when compared to traditional breeding alone.

GM traits, such as insect and herbicide tolerance, help to increase yields by protecting the yield that would otherwise be lost due to insects or weeds. The degree to which a farmer enjoys increased yields because of insect and herbicide tolerance traits will in large part be determined by how effective the farmer’s weed and insect control programs were before planting a crop with these traits. If weeds and insects had been controlled well, then the insect and herbicide tolerance traits will not be the primary factor in increasing yield.

In developing countries, where resources to effectively control weeds and insects are often limited, these traits have increased yield substantially. The same is also true for developed countries where there are particular pests that are hard to control--such as the corn rootworm complex or some perennial weeds.

The introduction of GM traits through biotechnology has led to increased yields independent of breeding. Take for example statistics cited by PG Economics, which annually tallies the benefits of GM crops, taking data from numerous studies around the world:

  • Mexico - yield increases with herbicide tolerant soybean of 9 percent.
  • Romania – yield increases with herbicide tolerant soybeans have averaged 31 percent.
  • Philippines – average yield increase of 15 percent with herbicide tolerant corn.
  • Philippines – average yield increase of 24 percent with insect resistant corn.
  • Hawaii – virus resistant papaya has increased yields by an average of 40 percent.
  • India – insect resistant cotton has led to yield increases on average more than 50 percent.

Even where insect and herbicide tolerance are not the primary factors in increasing yield, they provide many other benefits. Analysis by PG Economics also show that GM crops are credited with decreasing pesticide and fuel use, and with facilitating conservation tillage practices that reduce soil erosion, improve carbon retention and lower greenhouse gas emissions. Decreased inputs aren’t just a savings and convenience for farmers; they offer significant environmental benefits for everyone:

  • The reduction in greenhouse gas emissions associated with GM crops for 2006 is estimated to be equal to removing more than half a million cars from the road.
  • On average, the volume of herbicide used on corn has dropped 20 percent since herbicide tolerant corn was introduced in 1996.

Approximately 95 percent of the soybeans and 75 percent of the corn in the United States are GM. More than 95 percent of the soybeans in Argentina and half the soybeans grown in Brazil are GM. Where given the choice, farmers have consistently adopted GM crops quickly and widely because they see the improvement these products deliver. Whether it is increases in yield, or other benefits, farmers clearly see value in GM crops.

Misinformation and Setting the Record Straight
Irresponsible journalists and activists continue to misrepresent data and claim that GM crops actually reduce yields. For example, Geoffrey Lean recently published a story in the UK newspaper The Independent entitled Exposed: the Great GM Crops Myth. Lean concluded that yields were lower with GM crops based in large part on a study published by Dr. Barney Gordon of Kansas State University. Lean failed to understand or explain that the purpose of Gordon’s research was not to examine yields, but to look at how certain GM soybean varieties respond to manganese levels. Dr. Gordon has since published a response which characterizes the article as “a gross misrepresentation of my research and a good example of irresponsible journalism”.

Despite Dr. Gordon’s clarification and statements, some anti-GMO activists continue to reference the Gordon study and the Lean article as evidence of lower yields with GMOs. Dr. Mae Wan Ho of the Institute for Science in Society cited the Gordon study as evidence that biotech crops do not increase yields. The Center for Food Safety also referenced the study as evidence of decreased yields.

Additionally, a recent report by the Union of Concerned Scientists has stated the biotechnology has not increased yields in the United States. The report and its conclusions are flawed. Read more at:
Union of Concerned Scientists report on GM crop performance is misleading.
PG Economics, Ltd.

An analysis of “Failure to Yield” by Doug Gurian-Sherman, Union of Concerned Scientists
Wayne Parrott, Professor. Department of Crop & Soil Sciences, University of Georgia

Monsanto and other agricultural technology companies continue to improve germplasm, and to develop GM traits that are designed to directly increase yield, and more. In 2009, Monsanto will release a line of soybeans that has been shown in field trials to increase yields by 7-11 percent. We’ve made a public commitment to double yields in key crops by 2030. Equally important to increasing yield, we’ve committed to doing so with one-third fewer resources, such as fertilizer and water, per unit of output.

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And who made the study and by who was it financed? An objective opinion is hard to know!
Pierre Beaumont February 17, 2009

The only problem is; they are artificial and non sustainable. Not to add the fact that GM foods in the U.S are responsible for most illness.

Monsanto Note: Actually, there is no fact or figure out there that points to genetically modified organisms for illness of any kind. There is no documented case of human or animal illness from eating biotech foods. They are just as safe as their non-biotech counterparts. For more information, check out the resources here.

Allan February 18, 2009
Is the reduction in resource requirements per unit in terms of bu/a? If so, wouldn't a doubling of yields still require more resources than are currently being used?
Kyle February 19, 2009
If we are able to produce twice as much product on the same amount of land for a cheaper cost WHY wouldn’t we?? Tell me that. Do any of you have any hard evidence that biotech foods are responsible for most of the illness?
Jimmy February 22, 2009
Even if there really was any evidence that biotech foods were safe in the long term, privatizing seeds is the best way of reducing biodiversity and making farmers depends on only one firm, which would be, obviously : Monsanto, increasing his benefices, selling pesticides more and more each year because plants become more and more resistants to it, each year.
Bertrand February 26, 2009
I have lived in the uk all my life. i went to canada for a year and was wroking on a farm there. i ate gm food and food cooked with GM canola oil or OSR (europe).

the point is i did not get ill once while i was out there and are perfectly health there is nothing wrong with eating gm crops and i am from one of the counrties in the world which is against it! i also studying it for an assigment for my university in england and can see an negative effects.

unless you look deeply into the farming technique side of things where there maybe be concerns of development of super weeds due to cross pollination and there has been some evidence in the states with weeds becoming resistance to round up but the crop the same crops year on year so areas or the states where as rotational croping i think there would be less of a risk with super weeds and it may work better in europe.

but seriously open your eyes allan and reasurch dont just listen the the narrow minded few of the aint GMO groups. there are lots of benefits and some negatives more to do with farmer concerns then health concerns.
tom June 10, 2009