Bt cotton helps control pests

A study conducted in northern China showed that Bt cotton genetically engineered to kill insects not only reduced the number of insects harmful to itself but also reduced the number of insects in the same way. nearby are not genetically altered. This finding promises pest control methods that can maximize crop yields in the future.

The findings are published in the September 19 issue of Science. Science is a newspaper of AAAS - a non-profit science association.

Dr. Kong-Ming Wu of the Chinese Academy of Agricultural Sciences (Beijing) and colleagues analyzed data from 1997 to 2007 on the cultivation of Bt cotton in six northern provinces of China with an area of covering 38 million hectares of arable land and being cared for by 10 million farmers. They compared cotton planting data to data on the number of pests in the region, focusing primarily on cotton bollworms, which are a major damage crop for Chinese cotton growers.

The study results showed that the number of cotton bollworms was significantly reduced when Bt cotton was planted, especially during the period from 2002 to 2006. Researchers also calculated weak temperature, precipitation together with the introduction of new genetically modified cotton varieties; Since then, it has been confirmed that Bt cotton can withstand insect pests for a long time, and also support other unaltered crops within 10 years. Dr. Wu and his colleagues believe that it may be because cotton is the main host for egg bollworms to lay eggs, reducing the number of larvae in cotton means reducing the number of harmful insects said. General and protect other crops.

Bt is an insecticide derived from gametes and crystals with the toxin of Bacillus thuringiensis , which has been marketed since 1960. Bt is not toxic to humans, animals, animals. animals, bacteria and most insects. However, it is highly selective, causing the worm or caterpillar to die. Bt is now registered and sold for use as an insecticide in more than 50 countries worldwide, Bt does not contaminate groundwater because it decays very quickly.

Bt is an insecticide derived from the gametes and ephemeral crystals of Bacillus thuringiensis (as shown in photos).(Microscope image: Jim Buckman / Courtesy of Wikimedia Commons)

According to the study authors, Bt technology has helped China get a new pest control tool. All farmers in the Bt field benefit. In an email interview, Dr. Wu said: 'In 1992, cotton bollworm caused a loss of 30% of cotton production in northern China. Because the cost of insect control at that time was very high, many farmers did not want to plant cotton anymore. Research on this Bt cotton variety is also significant: all other Bt crops, such as Bt rice, can be cultivated extensively in China. Success with Bt cotton can promote commercial processes of genetically modified crops in China. '

Dr. Jian-Zhou Zhao, co-author of the study, also emphasized the health benefits of using Bt cotton. He said: 'Poisoning from other insecticides that can even lead to death is a major problem for cotton growers in the 1990s. Most farmers do not have appropriate protective clothing when spraying. Insecticide from a small spray bottle worn on the shoulder. This may be another reason why many farmers refused to plant cotton before Bt crops were available, because the cotton growing job was too dangerous and scary. '

The use of Bt cotton and other genetically modified crops can provide a more economical, safer solution for pest control on many small farms around the world. However, Wu and the team acknowledge that the biggest challenge to success on Bt trees is to overcome insect resistance . They claim that although there are significant qualities, only Bt cotton should be considered a factor in the control of pests in general.

The authors of the study include Kong-Ming Wu, Yan-Hui Lu, Hong-Qiang Feng, and Jian-Zhou Zhao of State Key Biological Laboratory of Pests and Plant Diseases, Plant Protection Institute , Chinese Academy of Agricultural Sciences (Beijing, 1000193, PR China)

Jian-Zhou Zhao has partnered with Pioneer Hi-Bred International, Inc., Johnston, IA 50131, USA. Yu-Ying Jiang is a member of the National Agricultural Technical Service and Extension Center, Beijing, 1000026, PR China.

The research was funded by the Ministry of Science and Technology of China and the National Natural Science Foundation of China.

Refer:
Wu et al.Suppression of Cotton Bollworm in Multiple Crops in China in Areas with Bt Toxin-Containing Cotton.Science, 2008;321 (5896): 1676 DOI: 10.1126 / science.1160550