BT (Bacillus thuringiensis) cotton is a genetically modified type of cotton that has been engineered to produce its own pesticide to protect it from harmful insects. It was first introduced in the United States in the mid-1990s and has since become a major crop in many cotton-growing countries around the world. However, there are different varieties of BT cotton, each with its own unique attributes that make it suitable for specific growing conditions.
One of the most common varieties of BT cotton is Bollgard I. This variety was first introduced in India in 2002 and has since been widely adopted by farmers across the country. Bollgard I is known for its ability to control the bollworm pest, which is one of the most devastating pests for cotton farmers. It has also been found to increase yields and improve the quality of the cotton lint.
Another variety of BT cotton is Bollgard II. This variety was first introduced in India in 2006 and is an improved version of the original Bollgard I. Bollgard II contains not only the toxin that targets the bollworm pest but also an additional toxin that targets the pink bollworm, another major pest that affects cotton crops. This additional toxin has helped to reduce the use of chemical pesticides and increase yields even further.
A third variety of BT cotton is a stacked trait variety. This type of BT cotton contains multiple BT genes that target different pests, making it resistant to a wider range of insects. For example, some stacked trait varieties may contain genes that target bollworms, pink bollworms, and other pests such as aphids. Thus, this variety can provide greater protection against multiple pests and help to improve crop yields.
In summary, the variety of BT cotton that farmers choose to plant will depend on a number of factors including the local pest pressure, growing conditions, and the farmer’s own preferences. While some varieties are better suited to specific growing conditions or to certain pests, all BT cotton varieties have the potential to improve yields and reduce the use of chemical pesticides. With continued research and development, it is likely that even more advanced varieties of BT cotton will be available in the future, further improving the profitability and sustainability of cotton farming.