Harvest of organic cotton.
A Greenpeace report reviewing the Chinese experience of GE Bt
(Bacillus thuringiensis) cotton shows adverse environmental impacts
after just five years of commercial growing, concluding that the
variety will be ineffective in controlling pests after eight to ten
years of continuous production. Bt cotton is the main GE crop
variety grown in large-scale commercial production in China.
Laboratory tests and field monitoring conducted by four Chinese
state-owned science institutes verify:
- a resistance build-up towards Bt in the main target pest,
cotton bollworm: susceptibility of bollworm to the Bt toxin fell to
30 percent after 17 generations under continuous feeding with Bt
cotton leaves. The resistance of the bollworm increased 1000 times
when the feeding was continued to the 40th generation.
- a significant reduction of the parasitic natural enemies of
- an increase of secondary pests: e.g. cotton aphids, cotton
spider mites, thrips and others, replaced the cotton bollworm as
primary pests in some of the cotton fields.
These factors have forced farmers to continue the use of
chemical pesticides, and increased the possibility of outbreaks of
certain pests due to the destabilized insect community.
The author of the study, a researcher at the Nanjing Institute
of Environmental Sciences, and an advisor for Greenpeace, Professor
Xue Dayuan, said:
"The report confirms that the Bt cotton is released to the
environment prematurely. After five years of growing, Chinese
farmers and scientists are now faced with serious problems and
confronted with the fact that too little is known about the
interaction of GE crops with the environment. High hopes have been
brought crashing down and reality shows that the information from
the GE industry has been unsubstantiated."
Bt cotton, a genetically engineered variety containing a gene
from soil bacteria inserted to produce a toxin that kills certain
types of pests, was first introduced to China in 1997 by Monsanto.
It was advertised as a magical fix to pest problems. Since then the
area of cultivation has increased to 1.5 million hectares in 2001,
which is 35 percent of the total cotton area. Monsanto's Bt cotton
accounts for two third of all GE cotton grown in China.
"As farmers growing this GE crop are now finding themselves
entangled in Bt-resistant superbugs, emerging secondary pests,
diminishing natural enemies, destabilized insect ecology, and the
need to keep spraying chemical pesticides to deal with the
increasingly uncontrollable situation, will Monsanto deal with any
of these problems their lack of precaution have caused?" asked Lo
Sze Ping, Greenpeace China program manager.
"The Chinese government has a role in helping the international
community to ensure that corporations such as Monsanto are held
liable for the damage they are causing by having developed and
released GE crops," Lo added.
View the report
summary of research on the environmental impacts of Bt cotton in