Thursday, October 25, 2018


Bt. Cotton;
What is the Bt. cotton:

“Bt. cotton is genetically modified variety of cotton”. It has been specially designed to fight against those insects who mostly attack the bolls of the cotton crop and try to damage the bolls of cotton fibres plants. Thus we can say that “Bt. cotton is an insect-resistant transgenic cotton crop”.

What is the objective of development of Bt. cotton?

When the cotton bolls come on the cotton plants, so many types of insects attack these cotton bolls. These insects make their food to these cotton bolls. Most of the cotton bolls become to damage and the productivity of cotton falls to the lowest level. The cotton farmers use many types of pesticides to kill these insects. Too much money is spent to buy these pesticides.
The main objective of development of Bt. cotton is to save the cotton crop from various types of insects. Since the Bt. cotton variety itself protects the cotton plant and cotton bolls from insects, therefore its secondary objective is to save money to buy pesticides. It also helps to maintain the quality of soil of the field.
The productivity of cotton crop is also improved.

How the Bt. cotton was developed:   

Bt. cotton was developed by genetically modifying the cotton genome to express a microbial protein from the bacterium “Bacillus thuringiensis. 

In brief, we can say that the transgene inserted into the plant's genome produces toxin crystals that the plant would not produce normally. When a certain population of organisms is ingested, this population of organism dissolves the gut lining and leading to the organism's death.

The History of Bt. Cotton:

Year -1901:  

A Japanese biologist, Shigetane Ishiwatari first time observed the bacterium Bacillus thuringiensis (Bt.) as the cause of the sudden-collapse disease.
 Year -1911: 

 Ernst Berliner first isolated a bacteria that had the capability to kill a Mediterranean flour moth and he re-discovered Bt. Since this moth was found in a German town Thuringia, therefore it was named  Bacillus thuringiensis by him.

Year -1915:

Berliner told the existence of a crystal within Bt.

Year -1956: 

H. Fitz-James, and Angus saw that the main insecticidal activity against lepidopteran (moth) insects was due to the parasporal crystal. This discovery came to increase the interest of biologists in the structure of the crystal, general mode of action of Bt. and biochemistry of it.

Year -1958: 

 In the US, Bt was used commercially. 

Year -1961

Bt. was registered as a pesticide to the EPA.


Use of Bt. increased when insects became more resistant to the synthetic insecticides. Scientists and people became more aware of the environment. Since the environment was harming by using chemical, and Bt. is organic and it affects specific insects and does not persist in the environment, therefore governments and private industries started to fund research on Bt.  

Year - 1995: 

With the advancement in molecular biology, it soon became feasible to move the gene that encodes the toxic crystals into a plant. The first genetically engineered plant, corn, was registered with the EPA. 

Year -1996: 

 Bt. cotton was introduced into US agriculture.
Year -2003: 

Bt. cotton was introduced in Indian cotton farming.

What are the advantages of Bt. cotton?

1 - production of the cotton crop is increased.
2 - the cost of production of the cotton crop is reduced.
- less use of pesticide help to improve the environment.
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