Hybrid Corn: A Case Study for Bioethics

Jochum Wiersma*, Don Duvick, Deon Stuthman, David Fan, and Victor Konde, Jochum Wiersma, Deon Stuthman, and David Fan, University of Minnesota, St. Paul, MN 55108; Don Duvick, Plant Breeding, Johnston, IA 50131; Victor Konde, Harvard University, MA 02138. * Corresponding author (


This case study exists of three parts. Please read the narrative and answer the questions following that section before continuing. This case is partially based on events in the past. It is very useful for the case to limit yourself to the facts as they are presented and imagine yourself as if you were there. There are several additional resources listed that you can use for background information.

Part I

In the twenties and early thirties of the last century corn breeders in the USA developed a practical way to make hybrid corn. Seed of "double cross hybrids" could be produced at a price farmers could afford. Farmers therefore could take advantage of the benefits of inbreeding followed by directed cross breeding of corn inbred lines that resulted in an increase in vigor and yield of the hybrid offspring. Dr. Duvick describes the rise of hybrid corn in the article "Biotechnology in the 1930s: the development of hybrid maize" in the January 2001 issue of Nature Reviews/Genetics. He states in the article that the technology was introduced even though corn breeders and other scientists did not (and still don't) understand the genetic principles of hybrid vigor, one of the major reasons for increased yield of hybrid corn.
The introduction of hybrids also allowed, for the first time, a cost effective protection of intellectual property in corn breeding. Farmers buying the seed could not maintain or recreate the hybrid themselves and thus needed to buy seed from the seed corn companies each year if they wanted to maintain the yield advantage the corn hybrids provided. This gave rise to a viable plant breeding industry. Numerous "seed corn companies" soon were responsible for much of the breeding and virtually all of the production and sales of hybrid corn in the USA (Figure 1). The farmers in the Corn Belt readily adopted this new technology and the majority of the acreage was planted to corn hybrids in just a few years (Figure 2). Corn yields immediately started to rise and are still rising, due in large part to annual improvements in hybrid genetics (Figure 3).

As with of any new endeavor, the start-up companies did have their share of doubts and problems. Attached below are excerpts from two letters written by the president of one of those start-up hybrid corn breeding companies. Both letters illustrate some of the dilemmas the president of the company was facing at the time.

Letter 1
July, 1934
[Our Company] is either something big or it is nothing at all. There is no halfway position. If it is nothing at all, we are wasting our time and effort and it makes little difference whether we waste it this way or that way. Our problems are imaginary, our solutions immaterial.

If [Our Company] is big, and we all believe it is, our problems are very real and the answers make a real difference to us and to the Iowa farmer. We have a selfish ambition to make money. We also have an unselfish desire to provide a better seed corn. Both ambitions are worthy and they are consistent with one another. We owe it to ourselves and to our neighbors to strive for proper solutions to our problems.
Our capital is $30,000.00. This is about 1% of what it should be. You know the task it has been to raise this 1%. The other 99% will not raise itself. ...

Letter 2
November 21, 1935

Dear --,

I have always thought that [Our Company] had but one serious threat: The chance that we would someday be fooled by a cross which would pass our tests, put it out commercially and then discover it was not any good. ... I feel we may have done this with [Hybrid X].

I think it is a fine corn if conditions are just right [but I believe it is] too sensitive to minor adversities. If I am right it is not a proper seed corn for general sale. ...

We gave [Hybrid X] the benefit of the doubt last spring and sold it. We made a sales profit. I doubt if we made a real long-run profit. I am afraid of [Hybrid X]. I want to take it off the market. ... If I jerk it off the market, [the Sales Department] will go wild for [they] can sell every grain of it. ... [But] I have told the boys ... to sell no more [Hybrid X] until further word.

--- ---, Pres.
November 21, 1935
(The hybrid had germinated poorly in 1935, and subsequently yielded less than expected.)


  1. What do you think were the reasons to introduce hybrid corn in the USA?
  2. Given the information presented, can you think of any objections to the introduction of hybrid seed corn?
  3. Given the pro and cons that you listed in questions 1 and 2, was it morally right to commercialize hybrid seed corn (defend your answer)?
  4. On what grounds do you think did the president of the company decide to halt the sale of the corn hybrid?
  5. Was it morally wrong for the company to release the hybrid in the first place (defend your answer)?
  6. Is it morally justifiable to protect and profit from the intellectual property and consequently create a dependency of the farmer on a seed source?

Part II

Hybrid corn was and is a huge scientific and commercial success. There were, however, unforeseen consequences of this technology. Existing (and genetically diverse) open-pollinated varieties throughout the Corn Belt quickly disappeared and consequently uniformity in the cornfields greatly increased. This increased the potential for genetic vulnerability as was demonstrated by the outbreak of Southern Corn Leaf Blight Race T, a fungal disease, in 1970. It was virulent to most hybrid cultivars at the time because of the genetic uniformity of the cytoplasm in those hybrids, due to use of a particular kind of Cytoplasmic Male Sterility (CMS) as an aid in production of the hybrids. The yield losses in the southern and central parts of the Corn Belt were disastrous. The average yield in the USA dropped considerably (Figure 3). The seed companies responded quickly and unilaterally abandoned Cytoplasmic Male Sterility in favor of mechanical detasseling to produce the hybrid seed. Already the next year, there were hybrids on the market that were produced normal cytoplasm, not vulnerable to the disease. Thus corn hybrids were no longer susceptible to Southern Corn Leaf Blight and individual farmers avoided any yield losses due to the disease.

  1. Do you change any of the answers to questions 1 through 5 given the additional information provided?

Part III

Now, fast forward to the present. Most of the opposition to genetic engineering and transgenic crops has focused on the potential risks of introducing genetically engineered plants into the environment and the purported unprincipled greed of multinational companies which, it is argued, will threaten food security and food safety. Some people are even willing to resort to violence to make their point as is illustrated by the press release below. In many of the debates the precautionary principle is used to defend the their stand on the issue. The Union of Concerned Scientists defines the precautionary principle as "potentially dangerous activities can be restricted or prohibited even before they can be scientifically proven to cause serious damage" ( The European Union has adopted the precautionary principle to be an integral part of policy making but does not provide an explicit definition of the precautionary principle (

Although difficult to verify, when hybrid corn was introduced, it appears that there was a lot less opposition and little if any discussion about the potential risks of hybrid corn. With the introduction of genetically engineered corn, the debate is very lively and discussions about the potential risks and benefits have been extensive. Pool and Esnayra (2001) provided a nice overview of the potential risks and benefits of transgenic crops. At the present there are hundreds genetically engineered corn hybrids on the market in the USA that are planted on a significant percent of the acreage in the USA.

As with the introduction of hybrid corn there have been unforeseen consequences with genetically engineered hybrid corn. In 2000, Aventis Crop Sciences was forced to remove the Starlink brand of corn hybrids from the market. The Starlink brand confers both resistance to the broad-spectrum herbicide Liberty as well as resistance to European corn borer and related pests ( stage/starlink/starlinkcorn.htm). The insect resistance results from production by the plant of a compound that is toxic to the Leptidoptora class of insects. At the time the Federal Drug and Food Administration had not yet approved the particular Bt toxin (Cry9A) incorporated in the hybrid corn for human consumption. However, traces of Starlink corn were found in several brands of corn tortillas, including Taco Bell, in the USA. Moreover, Japanese authorities found traces of Starlink corn in export shipments of corn to that country. These findings, ultimately, resulted in a voluntary withdrawal of any Starlink hybrid from the market by Aventis Crop Sciences on October 12, 2000.

Press Release

Date: October 29, 1999
Contact: Jeffrey Tufenkian 619-584-6462

An underground group opposed to genetic engineering (GE) claimed responsibility for breaking windows at the Eau Claire, Wisconsin Pioneer Hi-Bred facility on October 27th according to a communiqué released today. The group known as "Seeds of Resistance" charged Pioneer and other proponents of GE with deceiving the public and profiting off of growing GE crops. "Seeing their profits as a slap in the face of the earth and all its occupants, we took the liberty of paying them back," according to the communiqué. "We, Seeds of Resistance, smashed all the windows on one side of their disgusting building. Wisconsin is now another state that cannot hide from this growing resistance against GE culture." This action is the thirteenth known nonviolent destruction of GE crops or other property in the U.S. this year. Details of past anti-GE actions are available at

GenetiX Alert is an independent news center that works with other aboveground, anti-genetic engineering organizations. GA has no knowledge of the person(s) who carryout any underground actions. GA does not advocate illegal acts, but seeks to explain why people destroy genetically engineered crops and undertake other nonviolent actions aimed at resisting genetic engineering and increasing the difficulty for entities which seek to advance genetic engineering or its products. GA spokespeople are available for media interviews.

  1. Are there differences between the introduction of hybrid corn and the introduction of transgenic crops? Why or why not?
  2. Can you defend the precautionary principle on moral grounds?

References and Background Information:

Adventis Crop Sciences. 2000. Starlink Brand Corn (

American Corn Growers Association. Genetically modified crops: questions and answers (

Duvick. D. 2001. Biotechnology in the 1930s: the development of hybrid maize. Nature Reviews/Genetics. January 2001.

European Commission. 2000. Comments of the use of the precautionary principle - (

Goklany, I. 2000. Applying the precautionary principle to genetically modified crops. Policy Study 157. Center for the Study of American Busniness. Washington University, St. Lious.

Pool R., and J. Esnarayra. 2001. Ecological monitoring of genetically modified crops. Workshop Summary. Board on Biology, Board on Agriculture and

Natural Resources, National Research Council, Washington, D.C.

Union of Concerned Scientists (

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