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Genetically engineered, organically grown? [ pdf ]

By Pam Ronald, Sarah Hake, and Don Murch

Genetically engineered (GE) soybeans, corn, canola, cotton, and papaya are now widely grown in the US; many more GE crops are on the horizon. For Yolo farmers and consumers, planting and consumption of these crops is controversial.  One reason is that genetic engineering enables an extraordinary level of novelty, and thus ecological complexity, so that it is challenging to develop general guidelines that will protect both the consumer and the environment. Consumers, farmers, and scientists will need to assemble accurate information about genetic engineering and the potential impacts and work together to evaluate each GE crop on a case-by-case basis. If we are to utilize GE plants, risk to the consumers and the environment must be minimized and at the same time, reduction of synthetic pesticide and fertilizers maximized. Here, we would like to provide our perspective to help move the discussion forward.

All GE crops are not alike and thus cannot be discussed as a meaningful category. Each GE crop is unique with regard to its environmental impact, potential health effects, social and economic ramifications. The importance of critically evaluating the final plant variety rather than process (e.g. breeding or genetic engineering) has been emphasized in three independent National Research Council reports ( Generic discussions of the benefit or risk of genetic engineering only polarize the debate.

According to the leading UK and US scientific agencies, GE crops commercialized to date are safe to eat. In 2002, the US National Academy of Science ( concluded that the transgenic process itself presents no new categories of risk compared to conventional methods of crop improvement. Specific traits introduced by both approaches can pose unique risks. Furthermore the United Kingdom GM Science Review (July 2003; reported that after seven years of consumption of Round-up Ready corn/soybeans and Bt corn (genetically engineered to contain a bacterial protein Bacillus thuringiensis (Bt), which is naturally toxic to caterpillars) primarily in the United States, Argentina and Canada, not a single case of adverse health impacts has been documented. Bt)is considered “safe” to eat because it is digested in minutes and is not absorbed as a whole protein by the body. Furthermore farmers have been using Bt to control insects on organic farms for 30 years (at ca. 1 million times the concentration per 50 acre application than is found in a single ear of BT corn), with no adverse effects. Although Round-up Ready corn/soybeans and Bt corn, which account for 99 percent of consumer exposure to GE crops, are safe to eat; food safety cannot be generalized to all future crops, including GE crops. Each new crop must be evaluated on a case-by-case basis using the most rigorous scientific standards if the public is to be confident of conventional and GE crop safety.

The risks of growing GE crops need to be balanced with other risks inherent to conventional farming techniques. For example, we know that insecticides, synthetic and biologically derived, are extensively used on many crops, and can be highly toxic (many thousands of deaths per year, primarily of farm workers in developing countries). Production of Bt cotton has already led to enormous reductions in insecticide use in China (more than 150 million pounds less in China in 2001, equivalent to 25 percent of all of the insecticide sprayed before the adoption of Bt cotton). The exposure of farm workers to broad-spectrum pesticides has been correspondingly reduced (Toenniessen, et al; Plant Biology, 2003, 6:191-198). Although there is concern that pests will evolve to become resistant to Bt (which would normally occur if a pesticide is heavily used), the positive effects on farm workers and the environment should be considered when deciding on the merits of Bt crops.
Because organic farms use 97% less pesticide than conventional farms, organic production practices can contribute to reduction in pesticide use (Mader et al. 2002 Science 296:1694) However, after 25 years of development organic farms now constitute only ca. 1% of agriculture in the United States. To convert the remaining 99% of agriculture to more sustainable farming practices will take concerted efforts using all safe methods available.

With improved engineering and/or proper regulation, GE crops could coexist with other farming systems. Because genetic engineering is an “excluded method” in organic production (USDA National Organic Program Standards, section 205.2), organic growers fear that they will not be able to sell their crops if there is pollen drift from GE plants. Although the planting of GE crops could be banned altogether, an alternative solution is to identify tolerances that take advantage of the potential environmental and economic benefits of growing GE crops while limiting presence of transgenes in organic crops to low, but non-zero, levels. For example, the USDA national organic program standards tolerate set levels of pesticide drift (section 205.671), allowing organic farms to be located next to conventional farms that use pesticides. The same could be true of GE crops if tolerances for pollen drift are set at reasonable levels and liability is clear. Because many pesticides are known carcinogens, transition of conventional to GE crops would benefit neighboring organic farms as well as residents of rural areas who are exposed to pesticide drift on a regular basis.

In even the best-managed farming and food distribution system, there is still need to improve production practices. Thirty to 40 percent of potential global food, fiber and feed are lost to insects, nematodes, diseases and weeds. Sixty to 70 percent of these losses are in the developing world, at a cost of $300 billion a year. Abiotic stresses (e.g. drought or cold) account for even larger yield losses. Even incremental increases in the nutritional content, disease resistance, yield or stress tolerance of crops can go a long way to alleviating poverty by enabling farmers to produce and sell food locally, as well as by providing more nutritious food to help offset the malnutrition that affects one-sixth of the developing world and public sector scientists can play a role in this effort. Despite the increasing prominence and success of organic agriculture, there are still tremendous problems with pesticides, synthetic fertilizers, organic matter recycling and soil erosion in our agricultural systems. Because GE plant varieties can be integrated into any farming system and can be engineered to address local stress conditions, they could play a role in reducing some of the problems created by conventional agriculture. For example, new disease- and insect-resistant varieties could be developed that would significantly reduce pesticide use.

There may be problems in the present agricultural system that organic methods cannot solve, but genetic engineering can. For example, the papaya industry in Hawaii was virtually decimated by the presence of a single viral disease caused by the papaya ringspot virus (PRSV). A number of strategies, e.g., breeding for tolerance, cultural practices, and cross protection, failed to control the disease. The introduction of genetically engineered papaya in 1998 lead to a 20-fold increase in yield.The benefits extended to both conventional and organic growers because Hawaiian organic papaya can be grown disease free if it is produced near GE trees. This is because the GE fruit has all but eliminated the spread of the virus. In this case, GE tools were the cheapest, least technological and most accessible approach for addressing the problem.

Fair and reasonable decisions need to be made on labeling to provide useful information to consumers. The consumer has a right to know what is being consumed. However, a “GMO” label does not provide meaningful information. For example, although GE papaya contains trace amounts of GE papaya ringspot viral DNA, the genetic piece needed to provide immunization against the virus, organic papaya is likely to be virally infected and would therefore carry much higher levels of viral RNA as well as protein. What would be an informative label in either case?

The tools of genetic engineering and associated intellectual property (IP) must be accessible to less developed countries and for minor crops. The private sector focuses on crops such as corn and soybeans where markets are large, and the potential for profit great.  In contrast, the development of subsistence crops important to the developing world, and small specialty crops for the US, are left for public sector collaborations.  For example, in an attempt to reduce childhood blindness in South Asia, a rice variety was genetically engineered to produce pro-vitamin A.  This research effort was generated by funds from nonprofit institutions, primarily the Rockefeller Foundation; the major beneficiaries would be young children in developing countries. In contrast, development of Roundup-Ready® corn was privately funded; the major beneficiaries are large growers and private companies throughout the world.

Although many significant discoveries and technologies have been generated with public funding, these discoveries are often no longer accessible as "public goods" because they have been exclusively licensed to the private sector. To address this problem, the major agricultural universities in the United States (including UCD) and other public-sector institutions initiated a new paradigm in the management of IP to facilitate widespread availability of GE tools. The goal is to assure that the public sector will benefit from the opportunity presented by GE plants. (Science 2003. 301:174). UC Davis has also established a genetic resources recognition fund (GRRF) to recognize and compensate developing nation contributions to university IP (

 Conclusion Sustainable farming practices seek to:
  • Provide safe and nutritious food;
  • Minimally impact the environment;
  • Provide healthful conditions for farm workers;
  • Be profitable for farmers;
  • Foster ecological farming practices;
  • Benefit the local community; and
  • Improve the lives of the poor and malnourished

We see significant potential for GE crops to be integrated into and be a part of sustainable farming practices, just as organic practices will play a role. Through continued dialogue, we can enhance the world's ability to cope with the problems of pesticide use, fertilizer contamination of the environment, loss of topsoil, hunger, disease and environmental degradation.

  Pamela Ronald


Professor, University of California, Davis


Sarah Hake


Professor, PGEC and University of California, Berkeley


Don Murch, Grower


Gospel Flat Farm, Bolinas, CA

Marin Organic Certified Agriculture

Other Links

  • Genetically engineered organisms and the environment: current status and recommendations from the Ecological Society of America.
  • UK government five-year "genetically modified" science review.
  • Biotechnology and Hunger : a paper by Gordon Conway, Rockefeller Foundation.
  • This website, a part of the University of California biotechnology workgroup, provides science-based information to the public on issues relating to the application of biotechnology to crops.
  • Public intellectual property resource for agriculture is an initiative by universities, foundations and nonprofit research institutions to employ agricultural technologies to develop and distribute subsistence crops for humanitarian purposes in the developing world and specialty crops in the developed world.
  • In a step towards recognizing the source nations and institutes that have contributed to making possible important scientific advances, UC Davis has set up the Genetic Resources Recognition Fund (GRRF).
  • ASPB policy statement on genetic modification of plants using biotechnology
    Genetically Modified Crops: What Do the Scientists Say? A collection of editorials published in ßPlant Physiology May 2000-May 2001.
  • ASPB web site: Plant Research Briefing Papers
  • ASPB web site: Plant Biotechnology
  • These studies by the National Academy of Science assess the potential for adverse health effects from genetically engineered food. The committee notes that: The current GEO crops are safe to eat. Not a single case of adverse health impacts No scientific case for ruling out all GEO crops and their products. GEO applications need to be considered case-by-case. GEO regulation must keep pace with new developments. The transgenic process presents no new categories of risk compared to conventional methods of crop improvement.
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