Bt Levels Variations Are within a Biologically Explainable Range

Greenpeace recently presented in public the results of its study on the Bt concentration in insect-resistant maize. A total of 600 leaf samples from several fields of MON810 Bt maize in Germany and Spain were tested by a Swiss laboratory, Ecostrat, for Bt levels. The results of the tests showed that the Bt concentrations varied considerably and were not the same in every plant.

Johannes Jehle of the Dienstleistungszentrum ländlicher Raum (DLR) and colleagues, however, are not able to corroborate the results of the Greenpeace study. Jehle led a three-year research project in which Bt levels in genetically modified MON810 maize were measured. The researchers were able to demonstrate that Bt expression varies depending on the plant organ under investigation, the stage of development, the location and the weather. Over a period of three years with extreme weather differences, they measured variations that were 3 to 10 times smaller overall than those in the one-year Greenpeace measurements. The researchers concluded that the variations in Bt levels were within a natural, biologically explainable range.

To read more, visit http://www.gmo-safety.eu/en/news/568.docu.html.