Managing the biopesticide when it is inserted in
Bacillus thuringiensis (Bt) occurs naturally in soil. Insecticidal
strains, discovered in 1911, have been used for pest control since
moths are the main pests of cotton and, in the 1990s, INGARD ®
cottons containing a Bt protein toxic to them were released, resulting
in a substantial reduction in insecticide use where they are grown.
From season 2003/04, Australian growers will be able to plant BOLLGARD
II®, containing two Bt proteins.
plantings have led to a substantial reduction in the use of insecticides
on cotton but research doesn't end with the commercial release of
the GM cottons. Much effort goes on in the field and the lab in
the battle to prevent Helicoverpa developing resistance and
on assessing how effective these cotton varieties are across seasons
and in different conditions. And the search for additional toxic
For INGARD ®,
refuge crops are grown to provide a source of susceptible moths
to mate with Bt survivors, thereby diluting any resistance genes.
In BOLLGARD II®, it is hoped that the presence of two toxic
proteins which act differently will considerably slow the development
of any resistance.
Supported by: Australian Cotton Cooperative Research Centre,
Cotton Research and Development Corporation