So far, the only successful approach to engineering crops for insect tolerance has been the addition of Bt toxin, a family of toxins originally derived from soil bacteria. The Bt toxin contained by the Bt crops is no different from other chemical pesticides, but causes much less damage to the environment. These toxins are effective against a variety of economically important crop pests but pose no hazard to non-target organisms like mammals and fish. Three Bt crops are now commercially available: corn, cotton, and potato.
Bt cotton or Bollgard cotton is one of the miracles of the genetic engineering. Earlier, cotton farmers had only chemical pesticides to fight against the pests, especially to bollworm. With the introduction of Bt cotton, there is an in-built pest control mechanism created in the cotton plant to fight against the bollworm pest. This unbelievable truth came into reality with the help of genetic engineering techniques only. The genetic engineering innovation not only reduces the consumption of pesticides but also increases the productivity of cotton by protecting the crop effectively from bollworm attack.
The history of genetic engineering is about 30 years old. Initially, it was developed to isolate a desired gene from any organism so as to insert into another organism. At that time, no one could imagine that the growth of genetically engineered crop would be surprisingly increased by more than 30 folds, from 1.7 million hectares in 1996 to 52.6 million hectares (or 130 million acres) in 2001 i.e. within the span of five years only. However, during 2001, only four countries have grown 99 per cent of the total transgenic crop of the world. These countries are the US (35.7 million hectares i.e. 68 per cent of the world total), Argentina (11 million ha i.e. 22 per cent of the world total), Canada (3.2 million i.e. 6 per cent of the world total) and China (1.5 million i.e. 3 per cent of the world total).In case of transgenic cotton (Bt cotton), it was accounted for 13 per cent (6.8 million ha) of the total world transgenic crop cultivation area and approximately 20 per cent of the total world cotton cultivation area (34 million ha) in the year 2001.
In the history of Bt cotton, the toxin gene of bacterium was isolated in 1981 and in 1990 the first Bt protected cotton crop was field tested in USA. After the verification and examination of the safety and suitability of this crop by various government regulatory agencies of USA, Bt cotton was cultivated on 1.8 million acre in 1995. In 2001, the area of cultivation of Bt cotton in USA was 16.79 million acre showing more than ninefold increase in past six years. In 1997, China took up the cultivation of Bt cotton. Then 13 other countries followed it. In March 2002, cultivation of Bt cotton was allowed in India for large scale cultivation with certain conditions. The most important aspect for Bt cotton cultivation is the availability of Bt cotton seeds to the cultivators. At present USA and China have successfully developed Bt cotton seeds indigenously but only USA have commercialised the seed distribution to other countries of the world through its major seed company, Monsanto.
Bt Stands for Bacillus Thuringiensis. It is a genetically engineered variety of cotton that contains Bt gene. Bt gene is a soil bacterium used as an organic pesticide against the divesting caterpillar bollworm. Bt gene is also known as biological pesticide. In other words, Bt cotton is transgenic cotton with insect killer gene that is transferred to it from soil bacteria called Bacillus Thuringiensis (Bt). This gene produces a toxic protein, which is fatal to pests, particularly to bollworm. Thus cotton crop is effectively protected from the attack of bollworm.
So far as the quality of Bt Cotton is concerned, it resembles with a good variety of non-Bt cotton. This is because the transgenic insect resistant cotton is produced only by introducing insect resistant gene into the original cotton. It does not change the original properties of carrier plant. The carrier plant that is transformed into transgenic Bt plant is already of fine variety. So it resembles the many fine varieties of cotton.
Field trials have shown that farmers who grew the Bt variety obtained 25%-75% more cotton than those who grew the normal variety. Also, Bt cotton requires only two sprays of chemical pesticide against eight sprays for normal variety.
In terms of variety, there are various varieties of Bt cotton like the American DPL Series (Xinimian 33B 32, and 9B), the Zhongmian Series (ZM 29,30,32 and 36), the Gnokan Series (GK-12, GM-26, SGK-321), etc. In India only three varieties of Bt cotton have been approved i.e. MECH-12 MECH-162 and MECH-184.
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The major benefit of Bt cotton cultivation is the reduction in the use of pesticides, which thereby, reduces the cost of cultivation. Since it reduces the use of pesticides thereby minimising the chemical pollution of soil and atmosphere, it is recognised as environment friendly or Eco-friendly. In the non-Bt cotton cultivation, generally, 15 rounds of spray of chemicals are required in a season to control the pest especially the bollworm. But in case of Bt cotton crop only 3 rounds of spray of chemicals are considered enough. The cost of chemicals for a single round of spray is around Rs 300 per hectare. It means that more than Rs 3,500 could be saved per hectare if Bt cotton is cultivated. In India, cotton cultivation area is only 5 per cent of the total agricultural area but it consumes around 50 per cent of the total pesticides used for all the crops. In value terms the cost of pesticides used for non-Bt cotton cultivation is around Rs 2,000 crores.
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Besides this, the yield increases by 30 per cent by better protection from the pests. The increase in productivity consequently increases the income of cotton farmers significantly.
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In addition to the above, the studies indicate that a considerable extent of manpower is saved through reduced spray of pesticides in Bt cotton cultivation as compared to other varieties.
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Bt cotton technology also reduces the amount of exposure and risk involved in purchasing, transporting, mixing and spraying the insecticide (for caterpillar control) to the workers or cultivators of cotton.
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The first problem is that the seeds produced after cultivation of Bt cotton are not reusable. For each time, the farmer has to buy seeds from Monsanto-Mahyco. Since Monsanto is in a monopolistic position so they are free to charge any price. This means benefits of Bt cotton to cultivators will largely depend on the price of seeds at which they procure and availability of seeds at the time of season. In the long term, safeguarding the interest of farmers can be made against such a situation by developing indigenous technology.
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The second problem is that if Bt cotton is cultivated without the recommended method then bollworm pest might develop the resistance against Bt gene and that would lead to loss of effectiveness of natural eco-friendly pesticides forever.
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The third problem is the chance of availability of fake seeds of Bt cotton in the market. And it would be difficult for a farmer to differentiate between Bt and non-Bt cotton seeds. As a result the failure of crops and uncertainty of yield could be higher.
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There is also a big threat of gene contamination. It might be carried by insect or even wind that transfer pollen grains from Bt cotton to non-Bt cotton plants cultivated nearby.
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There is an urgent need to create awareness among the farmers about the entire Bt-technology and its functioning, because farmers are under the impression that Bt cotton is the panacea for all the woes (pest problem). They seem to understand that usage of Bt cotton seeds will eliminate the complete use of pesticides and production will increase considerably. This kind of myth should be removed from their minds or else this might lead to a situation where farmers start rejecting the technology in the event of not realising their expected gains. This kind of scenario will be dangerous for the country's cotton economy which requires infusion of latest technology and management practices for its overall growth.
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There is also great need for training to the cotton farmers about the recommended methods of Bt cotton cultivation i.e. 80 per cent of Bt cotton and 20 per cent of non-Bt cotton farming and 3 to 3.5 metre border plantation of non-Bt cotton in Bt cotton field. This minimises the chance of development of resistance in bollworm pests against the Bt gene and also reduces the chances of genetic contamination.
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For the welfare of Bt cotton cultivators, the government should establish an institution or organisation which will prevent the selling of fake Bt cotton seeds and also meet the requirement of Bt cotton cultivator regarding the type of training or help they need. This organisation should also be empowered to interfere in the pricing policy of Bt cotton seeds so that Bt cotton seed distribution companies do not charge extraordinary price to the cotton farmers. In order to check the fake Bt cotton seeds being supplied to the farmers, some private companies as well as CICR have already developed certain tools, but these are to be made available in the market at nominal prices.
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For the welfare of Bt cotton cultivators, the government should enact some law so that Bt cotton seeds distributor companies pay compensation to the Bt cotton cultivators in case of seeds failure under ideal conditions. A special crop insurance scheme may be developed.
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There is also a need for the development of indigenous Bt cotton seeds in India so that our farmers need not depend solely on Monsanto Bt cotton seeds.
Bt cotton is spreading very rapidly, driven by farmers' demand for technology that will reduce the costs of pesticide application and exposure to pesticides, and will allow them to use their time more profitably. They have been able to increase their yield per ha, and reduce pesticide costs, the time spent spraying dangerous pesticides, and the number of incidences of pesticide poisoning.
Bt cotton is undoubtedly the most extensively studied cotton variety today. Rigorous scientific studies conducted in India and abroad demonstrate that Bt cotton and its products are safe for the environment, humans, animals, and agriculture. In fact, the use of Bt cotton is a positive step towards environmental protection because it makes possible the reduction of the insecticide load in the environment and reduces handling of such chemicals by farmers. This reduced use of insecticides will enhance the effectiveness of biological controls and implementation of Integrated Pest Management (IPM) programs.
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