Bt (Bacillus thuringiensis) is naturally occurring soil bacterium. Different strains of Bt produce proteins that are lethal to different types of insects.
Using biotechnology techniques, Monsanto moved a specific Bt gene into cotton plants so that plants were able to produce their own specific bollworm controlling protein. By back-crossing these Bt cotton lines with top existing varieties in conventional breeding programmes, Bollgard cotton varieties with all the leading agronomic traits - plus the added benefits of built-in bollworm control - were developed.
No. Bollgard cotton is grown just like any other cotton variety, the only difference being that Bollgard will require much less spraying.
Bollgard cotton produces its own insecticidal protein, 24 hours a day, in every part of the cotton plant. However, the insecticidal properties of the protein are only effective against small larvae (<8mm). Once a bollworm larva has reached the 3rd or 4th instar, the amount of protein it ingests is not sufficient to kill it.
Two aspects are therefore very important
Firstly, you must keep your fields free of any other host plants from non-Bt crops that may have been planted in the previous season. If larvae survive to 3rd instar on weeds, and then move over to Bollgard cotton, the Bollgard protein will not kill them.
Secondly, it is very important to scout your fields for larvae (not eggs) regularly, so that you can quickly see if any resistance to the Bollgard protein is building up. It is important to prolong the life of this product as much as possible by preventing resistance build-up. Larvae that show tolerance to the Bollgard protein must be eradicated by spraying, so that they do no survive to pass on the tolerance to the next generation of bollworms. For this reason, Monsanto has insisted on growers also binding themselves to an Insect Resistance Management (IRM) strategy.
Yes - trials conducted in many parts of the world, including the USA and South Africa, have shown yield increases in the order of 5-20%. The probable reason for this is that the earliest squares are protected and therefore have the benefit of full growing season to mature.
No - there is no difference in fibre quality between a cotton variety with the Bollgard gene and the same variety without the Bollgard gene, grown under the same conditions.
No - Bollgard cotton does not have to be harvested separately. It may be delivered to your gin and handled in the same way as any other cotton.
No - at this stage no ratooning of Bollgard cotton is allowed. In the licence agreement, a grower must undertake not to ratoon any Bollgard cotton.
The main reason for this is related to the IRM strategy. By destroying a winter habitat for Bollgard - tolerant bollworms, growers will assist in reducing the risk of resistance development.
Bollgard technology provides all growers with a new tool to assist them to maintain economic and environmentally sustainable cotton production. These benefits will also flow through to the agricultural community.
Obviously Monsanto also hopes to achieve a fair return on their 25 years investment into biotechnology research.
There are many benefits, some obvious and others hidden. Here are a few that we have identified: