April 6th, 2005 –
Farmers have begun harvesting a vast crop of genetically modified cotton that
allowed them to slash the heavy use of pesticides for which they have long
been criticised.
With NSW and Queensland farmers free for the first time last spring to plant
as much GM cotton as they liked after nine years of caution, about 80 per
cent of the 300,000 hectares sown was genetically modified to resist herbicides
and fight the crop's enemy, the helicoverpa moth.
While cotton growers such as Bourke's Ian Cole would normally spray his crop
up to 18 times each growing season to kill off pest insects, this season he
only sprayed three times after choosing to grow a GM crop.
Those three sprays were targeted to attack sucking insects such as mites and
did not wipe out the "beneficials" - spiders, wasps and ladybirds
- as the powerful, broad-spectrum sprays for helicoverpa used to.
"I'm a big believer in technology being able to solve problems for us
in agriculture," Mr Cole said. "Technology has solved a huge problem
for us in cotton."
Over the years, traditional pesticides had became stronger and were applied
more frequently as insects built immunity.
Helicoverpa moths lay their eggs into the boll, or fruit, of the cotton plants
and when the larvae hatch they eat the fruit.
GM pioneer Monsanto first won permission for Australian farmers to grow its
Ingard GM cotton in 1996.
Ingard contained a gene found in soil bacteria that enabled the cotton to
produce a protein that killed the grubs when they ate the plant.
But because there was a risk of the helicoverpa developing immunity to the
single-gene product, planting of Ingard was limited to 30 per cent.
Now Monsanto has replaced Ingard with Bollgard II, which uses two genes and
produces two deadly proteins. The chance of insects developing immunity to
Bollgard is "extremely small", according to Mark Buckingham, a Monsanto
spokesman.
Ingard enabled farmers to more than halve the amount of pesticide spraying
they needed to do and Bollgard requires 85 per cent less pesticide than conventional
cotton.
As an ongoing safeguard, farmers planting Bollgard must also plant a "refuge
crop" of pigeon pea.
The theory is that any moths that do develop an immunity to Bollgard would
mate with moths that have fed on the nearby pigeon pea and have not developed
immunity. Their offspring would also not have immunity.
Apart from carnations, cotton is still the only GM crop allowed to be commercially
grown in Australia because of strict government regulations and strident opposition
from environmental and consumer groups.
Mr Cole said that as well as being great for the environment and the workplace
safety of his staff, Bollgard saved farmers a lot of money because they do
not have to spray as much and can devote more time to other matters such as
improving water efficiency. Cotton's thirst for water is the industry's other
public relations problem.
Globally, the area planted with GM crops rose 20 per cent last year to 81
million hectares - 5 per cent of the earth's cultivated crop land. More than
8 million farmers in 17 countries planted GM crops in 2004 and 90 per cent
were in developing countries. When commercial GM crops were first planted
in 1996, there were 1.7 million hectares.
Source:
Daniel Lewis (April 2nd, 2005). Poisonous harvest cut by GM crop. Sydney
Morning Herald (reproduced by permission of the publishers)
(http://smh.com.au/articles/2005/04/01/1112302240472.html?oneclick=true)
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