"Oz" wrote in message
...
Gordon Couger writes

There are hundreds of Bt natural BT proteins and hundreds more we can
take a
nasty racial on to make them more effective to meet the needs of killing
worms for a long time. As verities develop rotation of BT strains so less
resistance is likely to happen is a real likelihood.

Given the way resistance usually works I wouldn't count on new strains
of BT overcoming resistance. However BT isn't the only insecticidal bio-
control molecule.

Changing the chemistry of the BT protien has a good deal of potential. I
think they are also experimenting with introducing genes in the population
that make the population more susceptible. It requires a way to selectively
sterilize females and flood the area with males with the desired genetics.
If they can pull that off a lot of things become possible.

The ideal situation would be to have two separate systems to control worms
that you rotated world wide every 2 years. It would work for the seed people
with out much change by raising the systems off by one year. It would be a
little more expensive for them because they would have to save a little more
seed on the two years they skip because the germination of cotton falls off
with storage because of the high oil content and the oil going rancid. It
would be difficult to enforce in the third world but it is long past time
that education should have been brought to farmers around the world. It is
beyond belief the way most countries treat agriculture when it takes from 15
to 70% of their disposable income to eat.

So far the refuge method seems to work for cotton & corn in the US.

Worms are not a big problem anywhere we have farms unless we kill out the
benefices insects. One of the benefits of hot dry weather. We probably
double our money by planting BT cotton. It is mainly insurance in case we
have to spray for beet army worms or some other pest that is not very common
but may strike mid season and we can spray without committing to spraying
ever 5 to 7 days for the rest of the season.

Monsanto is releasing a BT that is more toxic to boll worms this year and
that should reduce the likelihood of resistance a little.

Unless BT crops cover a large area solid other crops and plants should serve
the purpose of a refuge in the third world. The worms that feed on cotton
and corn will eat about anything available.


Gordon