Frequently Asked Questions
Frequently Asked Questions about Biotech Cotton
- How does biotech cotton assist farmers?
- How does biotech cotton reduce the need for spraying?
- Has Bt cotton had a significant impact on spraying?
- Why do farmers have to spray at all if Bt cotton controls insects?
- Why must cotton farmers spray multiple times?
- 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?
- Are there any other biotech crops with built-in insect protection?
- Didn't a Cornell University laboratory study show that Bt corn pollen is harmful to monarch butterflies?
- Will insects develop resistance to Bt crops?
- Does Bt cotton provide economic benefits to farmers?
- Are there any other biotech traits in cotton?
How does biotech cotton assist farmers?
Biotech cotton allows farmers to spray less without sacrificing insect control, which saves time and money.
How does biotech cotton reduce the need for spraying?
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, insects that feed on the plant quit eating and die.
Has Bt cotton had a significant impact on spraying?
Yes. The National Center for Food and Agricultural Policy (NCFAP) calculated that cotton growers have reduced insecticide use by 2.7 million pounds (1.2 million kg) per year and made 15 million fewer insecticide applications annually due to planting Bt cotton. Other studies have shown that growers who planted Bt cotton made two to five and a half fewer insecticide applications per acre, with an average reduction of 3.2 sprays.1,2
Why do farmers have to spray at all if Bt cotton controls insects?
The current variety of insect protected cotton is more than 90 percent effective against the most important cotton pests - cotton bollworm, pink bollworm and tobacco budworm. It is not as effective against some lesser cotton pests, such as armyworms. If they are present at a high rate, farmers must spray.
Why must cotton farmers spray multiple times?
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. The impact can be dramatic. For example, in 1995, the year before Bt cotton was introduced, Alabama cotton fields were sprayed an average of 6.7 times for bollworms and budworms. Over the next three years, they were sprayed an average of 0.66 times for those two pests.3
Is Bt cotton widely planted by farmers?
Bt cotton was introduced in 1996 on 12 percent of U.S. cotton acres.4 Planting indications for 2002 are for farmers to plant biotech cotton varieties on a total of 71 percent of the U.S. cotton crop.5 Internationally, Bt cotton was planted on an estimated 3.2 million hectares (7.9 million acres) in 2000.6
Does Bt cotton offer benefits to farmers in developing countries?
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. Chinese farmers who used Bt cotton applied 80 percent less insecticide than farmers who planted non-Bt varieties.
Is Bt cotton harmful to all insects?
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.
Can Bt cotton harm the caterpillars of desirable insects such as butterflies?
The Bt protein is effective only if consumed by insects. Butterfly caterpillars, which do not feed on cotton, typically are not exposed to the protein.
Can Bt cotton be harmful to desirable insects that feed on cotton pests?
No. The protein is effective only against the caterpillars of lepidopteran insects (moths). It is not harmful to ladybugs, lacewings, spiders or other arthropods.7
Is Bt cotton safe for soil organisms as the cotton plants degrade after harvest?
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.8 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.
Are Bt crops tested for safety?
Yes. Three federal agencies have regulatory responsibility - 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 food safety and environmental analyses are required before the products can be approved for use.
Are there any other biotech crops with built-in insect protection?
Yes. Bt traits also have been introduced into corn and are expected to account for 24 percent of the corn acres planted in the United States this year. An estimated 32 percent of total corn acres will be planted to biotech crops of one type or another this year. Bt traits also have been introduced into potatoes and sweet corn, but these crops are not commercially available.
Didn't a Cornell University laboratory study show that Bt corn pollen is harmful to monarch butterflies?
That laboratory study was not reflective of field conditions. Researchers from several universities conducted two summers of field research and concluded that pollen from Bt corn is not a threat to the monarch population.9
Will insects develop resistance to Bt crops?
Farmers who use Bt crops are required to implement insect resistance management plans to protect against resistance.10,11 In 2001, EPA reviewed new data and performance from the first five years and extended the registration of Bt cotton for an additional five years; Bt corn was extended for seven more years. EPA concluded there was no evidence of resistance.
Does Bt cotton provide economic benefits to farmers?
The National Center for Food & Agricultural Policy concluded that Bt varieties required an average 3.9 fewer insecticide sprays for bollworm/budworm, cost $15.43 per acre less for insect control, yielded 37 pounds more lint per acre and resulted in $39.86 more profit per acre.12
Are there any other biotech traits in cotton?
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 and keeps sediment out of streams. An estimated 59 percent of the 10.5 million acres of U.S. cotton will be planted in herbicide tolerant varieties in 2002.13
1 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>.
2 Edge, J.M., J.H. Benedict, and J.C. Carroll. "Agricultural, Environmental, and Societal Benefits of Bollgard® Cotton After Four Years of Commercial Production," 2000, Monsanto, St. Louis, MO.
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 "Annual Spring Planting and Crop Production Survey," USDA Agricultural Statistics Board, March 28, 2002, <usda.mannlib.cornell.edu>.
6 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>.
7 "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.
8 "Bt Corn Poses No Significant Risk to Monarchs," USDA Agricultural Research Service, February 6, 2002, <www.ars.usda.gov/is/pr/2002/020206.htm>.
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 "Biopesticides Registration Action Document, Bacillus thuringiensis Plant-Incorporated Protectants," U.S. Environmental Protection Agency, October 16, 2001.
11 "Bt Cotton Refuge Requirements for the 2001 Growing Season," U.S. Environmental Protection Agency.
12 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>.
13 "Annual Spring Planting and Crop Production Survey," USDA Agricultural Statistics Board, March 28, 2002, <usda.mannlib.cornell.edu>.