Frequently Asked Questions
Frequently Asked Questions about Biotech Cotton
- What is biotech cotton?
- How does biotech cotton assist farmers?
- Has Bt cotton had a significant impact on spraying?
- Is Bt cotton widely planted by farmers?
- Does Bt cotton offer benefits to farmers in developing countries?
- Is Bt cotton harmful to all insects?
- Can Bt cotton harm the caterpillars of desirable insects such as butterflies?
- Can Bt cotton be harmful to desirable insects that feed on cotton pests?
- Is Bt cotton safe for soil organisms as the cotton plants degrade after harvest?
- Are Bt crops tested for safety?
- Will insects develop resistance to Bt crops?
- Does Bt cotton provide economic benefits to farmers?
- Are there any other biotech traits in cotton?
Biotech cotton contains a protein taken from a bacterium known as Bacillus thuringiensis or Bt. Bt is a natural insecticide that has been used in spray or powder form for many years, especially by organic farmers. When it is introduced into the cotton plant through biotechnology, it provides effective protection against insects such as bollworms and budworms, which Bt effectively targets.
Biotech cotton allows farmers to spray less without sacrificing insect and weed control, which saves time, fuel, and money.
Absolutely! Spraying has been sharply reduced. In Georgia, for example, cotton farmers sprayed their fields an average of around five times a year from 1992 through 1995. When Bt cotton was introduced in 1996, the need for spraying immediately dropped and has averaged just over two applications per year from 1996 to 2011, according to the Cooperative Extension Service at the University of Georgia.1,2. Without Bt cotton, multiple sprays are needed because multiple generations of insects occur during the growing season, and not all eggs hatch at the same time. Bt cotton provides built-in, season-long control so the protection is there when insect control is needed. However, spraying can be needed to control insects that are not affected by the biotech cotton varieties.3
Bt cotton was introduced in 1996 on 12 percent of U.S. cotton acres.4 By the year 2012, Bt cotton had come to dominate the market, being planted on 94 percent land planted to upland cotton. 5 Internationally, Bt cotton was planted on an estimated 24.7 million hectares (61 million acres) in 2011.6
Yes, insect protected cotton is especially important in developing countries where small farmers may have less access to machinery and crop inputs, or must apply pesticides with hand sprayers under difficult conditions. Biotech cotton allows them to use much less chemical pesticide. A study in China showed that farmers who used Bt cotton applied 80 percent less insecticide than farmers who planted non-Bt varieties.7
No. The protein in Bt cotton is effective only against the larval form (caterpillars) of certain moths. Specifically, it targets bollworms and budworms that feed on cotton. Susceptible insects have a receptor in their gut to which the Bt protein attaches. The receptor is not present in mammals, birds, fish and most other forms of insects, so the protein has no effect on them.
The Bt protein is effective only if consumed by certain insects. Butterfly caterpillars, which do not feed on cotton, typically are not exposed to the protein.
No. The protein is effective only against the caterpillars of lepidopteran insects (moths). It is not harmful to ladybugs, lacewings, spiders or other arthropods.8
Impacts of Bt proteins have been investigated on a wide variety of terrestrial and aquatic invertebrates, including earthworms, collembola, daphnids, insect predators and parasites, spiders and honey bees.9 Even though test populations were exposed to levels 500 to 1,000 times greater than concentrations measured in the field, in most cases no adverse effects were observed.
Three federal agencies have regulatory responsibility for biotech plants - the Food and Drug Administration (FDA), the Environmental Protection Agency (EPA) and the Department of Agriculture's Animal and Plant Health Inspection Service (APHIS). Extensive safety and environmental analyses are required before the products can be approved for use.
Farmers who use Bt crops are required to implement insect resistance management plans to protect against resistance. This typically includes "refuge" requirements, in which a certain amount of conventional plants are grown along with the biotech varieties. By leaving non-Btcrops in the field, insects who feed on that crop remain susceptible to Bt technology. Then, when they mate with the few insects who survive feeding on the Bt crop, the offspring are susceptible to the technology. This helps to preserve the effectiveness of Bt technology.
According to studies cited by the National Academies in a report on the farm-level impacts of genetically engineered crops, biotech varieties yielded as much as 14 percent more cotton per acre than conventional varieties and that the cost of use of insecticides were ?drastically reduced.? ?Where measurable, farm-level profit was also shown to have increased with the adoption of Bt cotton in all states,? the report said. 10
Yes. Some cotton has been improved to resist a herbicide that controls a broad spectrum of weeds. In many cases, this enables farmers to use one herbicide instead of multiple products. Herbicide tolerant crops are also very compatible with conservation tillage, which protects soil from erosion.
12012 Georgia Cotton Production Guide, Cooperative Extension, University of Georgia
2 Purcell, J.P. & Perlak, F.J. (2004). Global impact of insect-resistant (Bt) cotton. AgBioForum, 7(1&2), 27-30. Available on the World Wide Web: http://www.agbioforum.org.
3 Carpenter, J. and Gianessi, L., "Agricultural Biotechnology: Updated Benefits Estimates," 2001, National Center for Food and Agricultural Policy. <www.ncfap.org/reports/biotech/updatedbenefits.pdf>.
4 James, Clive, "Global Review of Commercialized Transgenic Crops: 2000," ISAAA Briefs No. 23-2001, International Service for the Acquisition of Agri-biotech Applications, <www.isaaa.org/publications/briefs/Brief_24.htm>.
5 "Acreage," USDA National Agricultural Statistics Service, 2012 <http://usda01.library.cornell.edu/usda/current/Acre/Acre-06-29-2012.pdf>.
6 James, Clive, "Global Status of Commercialized Biotech/GM Crops: 2011 " International Service for the Acquisition of Agri-biotech Applications, <www.isaaa.org/publications/briefs/Brief_43.htm>.
7 "Biotechnology as an alternative to chemical pesticides: a case study of Bt cotton in China," Jikun Huanga, Ruifa Hu, Carl Pray b, Fangbin Qiao c, Scott Rozelle; Agricultural Economics 29 (2003) 55?67
8 "Biopesticide Fact Sheet. Bacillus thuringiensis subsp. kurstaki Cry1Ac Delta-Endotoxin and Its Controlling Sequences as Expressed in Cotton," U.S. Environmental Protection Agency, (006445), April 2000.
9 "Bt Corn Poses No Significant Risk to Monarchs," USDA Agricultural Research Service, February 6, 2002, <www.ars.usda.gov/is/pr/2002/020206.htm>.
10 "Impact of Genetically Engineered Crops on Farm Sustainability in the United States." Committee on the Impact of Biotechnology on Farm-Level Economics and Sustainability, National Research Council. Washington, DC: The National Academies Press, 2010.