Farmer Wang Fengtong found herself in a difficult situation when
choosing what kind of cotton to plant in the spring.
The 40-year-old from Mazhuang village of Xinjin city, in north
China's Hebei Province, eventually decided to keep
planting the genetically modified (GM) cotton, although its
anti-insect effect "seems to have been decreasing."
Speaking to China Daily in a phone interview yesterday,
she said:"After all, its benefits are still higher than those of
conventional types of cotton, and labor is saved."
Mainstream agricultural experts say a more effective way of
managing GM crops is needed if farmers are to keep enjoying the
seeds' benefits in the future.
The government approved the sale of genetically modified cotton,
tomatoes, pimientos and a species of morning glory in the late
1990s. GM cotton, with a Bacillus thuringiensis (Bt) gene inserted
to produce toxins, has proven effective against bollworms, a major
cotton pest.
Since its commercialization in China in 1997, Bt cotton sales
have expanded rapidly, with the total planted area reaching 3.3
million hectares in 2005, accounting for nearly 60 percent of all
the cotton growing in China.
But a study carried out by Cornell University researchers based
on data provided by the Center for Chinese Agricultural Policy
(CCAP) under the Chinese Academy of Sciences (CAS) last month was
less than optimistic.
It found that although Bt cotton reduced pesticide use by more
than 70 percent between 2001 and 2004, since then secondary insects
mainly mirids, which are not targeted by the Bt gene have arisen,
and many GM cotton growers have ended up using the same amount of
pesticides as farmers who planted conventional cotton.
What's more, the GM cotton farmers, who had been earning 36
percent more than farmers planting conventional cotton in 2001-04,
earned 8 percent less than conventional cotton farmers last year
because of higher Bt seed prices, the study said.
"These results should send a very strong signal to researchers
and governments that they need to come up with remedial action for
Bt cotton farmers," said Per Pinstrup-Andersen, the lead scientist
in the study and a professor of food, nutrition and public policy
at Cornell.
However, CCAP director Huang Jikun said the Cornell team's
conclusions could be based on an incorrect reading of the data.
According to Huang, 2004 had particularly low summer
temperatures and more precipitation, so the mirids affected not
only cotton but also other conventional crops nearby.
CCAP interviews with the same farmers in 2005 and 2006 showed
fewer mirids.
"In addition, it is not fair to compare the income of Bt cotton
growers with that of nearby conventional cotton farmers because the
long-time planting of Bt cotton has dramatically reduced the
bollworm population not only on GM cotton farms but also on nearby
non-GM farms, decreasing the latter's pesticides costs," said
Huang.
But Huang did agree that it is important to study and develop
strategies against the secondary insects not dealt with by Bt
crops.
Zhang Yongjun, a senior research fellow at the Institute of
Plant Protection of the Chinese Academy of Agricultural Sciences,
said the rise of the secondary insect problem was mainly due to the
poor management of GM cotton growth in China.
Before planting anti-insect cotton, Chinese farmers widely used
broad-spectrum pesticides, which killed both bollworms and mirids.
But using the pesticides increased costs, caused pollution and
harmed farmers' health.
After planting anti-insect cotton, however, farmers use
pesticides only in the final stage of the crop's growth, when the
Bt cotton's resistance against bollworms is relatively reduced.
"But in terms of preventing mirids, it's too late," said Zhang.
That situation, coupled with weather factors, eventually led to
the outbreak of mirids across cotton-growing provinces in 2004,
Zhang explained.
If the proper pesticide had been used at the right time, the
mirids could have been controlled in 2004, he said.
Besides the threat of secondary insects, there are too many
types of GM anti-insect cotton in the market to select an ideal
type, said Su Guizhen, a cotton farmer in Dalisu village in
Xinsu.
After planting Bt cotton for several years, Su and her husband,
Wang Changshan, decided to shift to conventional cotton, with which
she said they were more familiar.
"We were not certain which type of anti-insect cotton has better
effects or higher output," said Su.
Hu Ruifa, a senior researcher at CCAP, said that although
there's nothing wrong with planting GM cotton, an integrated
management is urgently needed in China, including seed management,
pest observation and training in pesticide uses.
"This is not only needed to maintain the benefits GM cotton can
bring," Hu said, "but also for the sustainable development of
China's agricultural biotechnology as a whole."
(China Daily August 7, 2006)