The Present and Future Role of Insect-Resistant GM Crops in Cotton IPM

Authors: Naranjo, Steven; RUBERSON, JOHN - DEPT OF ENTMLGY,TFTN,GA; SHARMA, HARI - ICRISAT, INDIA; WILSON, LEWIS - CSIRO INDTRY,WALES,AUSTRA; KONGMING, WU - CHNS AG SCNC,BEIJING,CH

Submitted to: Integration of Insect-Resistant Gm Crops within IPM Programs
Publication Type: Book / Chapter
Publication Acceptance Date: 3/27/2008
Publication Date: 7/14/2008
Citation: Naranjo, S.E., Ruberson, J.R., Sharma, H.C., Wilson, L., Kongming, W. 2008. The Present and Future Role of Insect-Resistant GM Crops in Cotton IPM, p. 159-194. In: Integration of Insect-Resistant GM Crops within IPM Programs, J. Romeis, A.M. Shelton & G.G. Kennedy (eds.), Springer, New York.

Interpretive Summary: Cottons that have been genetically modified to express the protein toxins of a common soil bacteria, Bacillus thuringiensis (Bt), have been commercially available since 1996. These cottons provide for very selective control of caterpillar pests such as bollworms and budworms, which are the most damaging pest of cotton, and have become a major integrated pest management tactic in cotton production systems throughout the world. As of 2006, a total of nine countries (Argentina, Australia, Brazil, China, Colombia, India, Mexico, South Africa, and the USA) now grow Bt cotton with a total area of production of 12.2 million hectares. Economists estimate that over the past ten years the use of Bt cotton has reduced the volume of insecticide active ingredient used for pest control in cotton by 94.5 million kg and increased farm income through reduced costs and improved yields by US$7.5 billion, with most of the benefit accrued by farmers in developing nations. Insecticide use in cotton has declined overall resulting in broadened opportunities for biological control of all cotton pests. Most other pest management tactics have remained largely unchanged by the introduction of Bt cotton. Several non-target pests have become more problematic in Bt cotton fields in some countries largely due to reductions in insecticide use for target pests. After 10 years Bt cotton cultivation, resistance had not been detected under field conditions, and this success can be largely credited to pre-emptive resistance management and monitoring programs in most adopting countries. A number of new GM cotton products are in the pipeline to improve the effectiveness of resistance to caterpillars and other key cotton pests. Debate over food and environmental safety, regulatory oversight, and farming community welfare are likely to continue as the technology moves forward with new crops and new adopting countries.

Technical Abstract: Transgenic cottons producing Cry toxins from Bacillus thuringiensis (Bt) provide for control of lepidopteran pests and were first commercially grown in Australia, Mexico and the USA in 1996. As of 2006, a total of six additional countries (Argentina, Brazil, China, Colombia, India, and South Africa) now grow Bt cotton with a total area of production of 12.2 million hectares. The technology primarily provides for highly selective and effective control of bollworms which are the most damaging pests of cotton worldwide. It is estimated that between 1996 and 2005 the deployment of Bt cotton has reduced the volume of insecticide active ingredient used for pest control in cotton by 94.5 million kg and increased farm income through reduced costs and improved yields by US$7.5 billion, with most of the benefit accrued by farmers in developing nations. Reductions in insecticide use have broadened opportunities for biological control of all cotton pests but most other pest management tactics have remained largely unchanged by the use of Bt cotton. Several non-target pests have become more problematic in Bt cotton fields in some countries largely due to reductions in insecticide use for target pests. After 10 years Bt cotton cultivation, resistance had not been detected under field conditions, and this success can be largely credited to pre-emptive resistance management and monitoring programs in most adopting countries. New products are in the pipeline to improve the effectiveness of genetically modified cotton cultivars for resistance to lepidopteran pest, and address other pest problems in cotton. Debate over food and environmental safety, regulatory oversight, and farming community welfare are likely to continue as the technology moves forward with new crops and new adopting countries.