The Halo Effect: Suppression of Pink Bollworm on Non-Bt Cotton by Bt Cotton in China


In some previously reported cases, transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce Bt toxins. Here we used 16 years of field data to determine if Bt cotton caused this “halo effect” against pink bollworm (Pectinophora gossypiella) in six provinces of the Yangtze River Valley of China. In this region, the percentage of cotton hectares planted with Bt cotton increased from 9% in 2000 to 94% in 2009 and 2010. We found that Bt cotton significantly decreased the population density of pink bollworm on non-Bt cotton, with net decreases of 91% for eggs and 95% for larvae on non-Bt cotton after 11 years of Bt cotton use. Insecticide sprays targeting pink bollworm and cotton bollworm (Helicoverpa armigera) decreased by 69%. Previously reported evidence of the early stages of evolution of pink bollworm resistance to Bt cotton in China has raised concerns that if unchecked, such resistance could eventually diminish or eliminate the benefits of Bt cotton. The results reported here suggest that it might be possible to find a percentage of Bt cotton lower than the current level that causes sufficient regional pest suppression and reduces the risk of resistance.

Pink bollworm abundance on non-Bt cotton before and after adoption of Bt cotton.

Volledige artikel in Plos One.

Widespread adoption of Bt cotton and insecticide decrease promotes biocontrol services

Over the past 16 years, vast plantings of transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) have helped to control several major insect pests12345 and reduce the need for insecticide sprays156. Because broad-spectrum insecticides kill arthropod natural enemies that provide biological control of pests, the decrease in use of insecticide sprays associated with Bt crops could enhance biocontrol services789101112. However, this hypothesis has not been tested in terms of long-term landscape-level impacts10. On the basis of data from 1990 to 2010 at 36 sites in six provinces of northern China, we show here a marked increase in abundance of three types of generalist arthropod predators (ladybirds, lacewings and spiders) and a decreased abundance of aphid pests associated with widespread adoption of Bt cotton and reduced insecticide sprays in this crop. We also found evidence that the predators might provide additional biocontrol services spilling over from Bt cotton fields onto neighbouring crops (maize, peanut and soybean). Our work extends results from general studies evaluating ecological effects of Bt crops123461213 by demonstrating that such crops can promote biocontrol services in agricultural landscapes.
Nature letter

Een opzettelijke leugen, of moeten ze nog leren lezen bij Greenpeace?

Officiële website van ministerie van landbouw in China:

“Research, selling, importing and exporting of transgenic grain seeds should comply with state regulations. Any institution or individual must not apply transgenic technologies to principle grain cultivars without approval, said the draft of a law referring to transgenics, the practice of inserting into an organism DNA that is not normally present.”

“It will be impossible for transgenic corn and rice to appear on the market if their commercial production is not approved by relevant departments, Chen Xiwen, director of the Office of Central Rural Work Leading Group, said at a press briefing earlier this month.”

Greenpeace maakt daarvan: 

“We’re ecstatic to announce a new legal initiative in China that’s set to keep GM away from the country’s staple food.”

“The State Council has released the draft proposal of a grain law that establishes legislation restricting research, field trials, production, sale, import and export of genetically modified grain seeds. The draft stipulates that no organization or person can employ GM technology in any major food product in China.”

China’s Agricultural Biotechnology Regulations—Export and Import Considerations

China has a biosafety regulatory framework in place for both domestic GM crop commercialization and imports. China imported about four times as many soybeans as it produced domestically in 2010 and is also expected to become a major importer of maize in the near future. Both China’s soybean and maize imports are dominated by GM varieties, with most soybean imported from the US, Brazil and Argentina and maize imported mainly from the US.

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Potential impact and cost-effectiveness of multi-biofortified rice in China


Biofortification, that is, improving the micronutrient content of staple foods through crop breeding, could be a pro-poor, pro-rural, agriculture-based intervention to reduce the health burden of micronutrient malnutrition. While the potential cost-effectiveness of crops biofortified with single micronutrients was shown in previous research, poor people often suffer from multiple micronutrient deficiencies, which should be accounted for in biofortification initiatives. This study is the first to estimate the potential health benefits and cost-effectiveness of multi-biofortification. Rice with enhanced provitamin A, zinc, iron and folate concentrations is used as a concrete example. The research is conducted for China, the largest rice producer in the world, where micronutrient malnutrition remains a major public health problem. Using the DALY (disability-adjusted life year) framework, the current annual health burden of the four micronutrient deficiencies in China is estimated at 10.6 million DALYs. Introducing multi-biofortified rice could lower this burden by up to 46%. Given the large positive health impact and low recurrent costs of multi-biofortification, this intervention could be very cost effective: under optimistic assumptions, the cost per DALY saved would be around US$ 2; it would stay below US$ 10 even under pessimistic assumptions. Continue reading