According to the University of Tennessee's Agricultural Extension, Bt Cotton is a genetically modified cotton crop that has one or two genes of a soil bacterium inserted into the seeds of cotton. Bt Cotton is described by the University of Tennessee as producing insecticidal proteins and toxins that reduce the amount of cotton lost to insects.
Bt Cotton seeds were introduced by Bollgard Cotton, a trademark of the Monsanto group. Bt Cotton was first introduced to the U.S. in 1996 according to the University of California San Diego and was aimed at reducing the effects of the tobacco budworm and the pink bollworm. Tests began at the same time around the world on crossing the American Bt Cotton seeds with cotton produced in other countries, including India, according to the Science & Development Network. Later versions of Bt Cotton were introduced in 2003 and 2004 aimed at reducing the impact of a wider range of insects than the original version.
The University of California San Diego describes Bt Cotton as containing a bacterium called Bacillus Thuringiensis (Bt). The spores of Bt produce crystal proteins which are toxic to many forms of insects, leading to its use as an insecticide. The University of California San Diego reports Bt is found throughout the world in a variety of soils in very small amounts producing thousands of different strains of Bt. The University of California San Diego reports Bt does not produce food poisoning proteins, Despite being a member of the food poisoning Bacillus Cerus family of bacterium; Bt Cotton has a very small chance of cross contamination due to its lack of use in food production.
The benefits provided by Bt Cotton are explained by the University of California San Diego as including a reduced cost per acre of between $25 and $65 in the years of 1996 to 1998 from the spraying of insecticides. Bt Cotton crops are estimated by the University of California San Diego to have yielded around 5% more cotton than traditionally grown cotton crops planted during the same time period.
According to the Science and Development Network, Bt Cotton crops in India are being affected by the bollworm that is becoming resistant to the Bt toxins and proteins produced by Bt Cotton. Bt Cotton is one of the 21 genetically modified crops introduced to 21 countries around the world by 2006. Four of the 21 crops are reported by the Science and Development Network to have been affected by insects resistant to the insecticides initially introduced to the crops.
The insecticide introduced to each version of Bt Cotton is reported by the University of California San Diego to be created to be specific to the insect at which it is aimed. The use of Bt Cotton as an organic form of insecticide is commonly used in organic farming and in aerial spraying of urban areas.