Inventory of observed unexpected environmental effects of genetically modified crops

Abstract

In general, it can be concluded that very few clearly unexpected effects were observed during the large scale post-release growing of herbicide-tolerant crops and Bt crops. Of course, one has to keep in mind Applied Plant Research (Praktijkonderzoek Plant & Omgeving ) 14 that there will always be an element of subjectivity in assessing effects as “unexpected”. Furthermore, it is also possible that certain effects are becoming visible only after a longer period than 10 – 15 years, but no indications for such effects were found in the literature. Besides the reports about the Farm Scale Evaluations no other reports were found with information about effects of GM crops on biodiversity in ecosysystems surrounding the production fields. Unexpected effects caused directly by the genetic modification were not found. Only in herbicide-tolerant crops, we concluded to some indirect unexpected effects: the reduced uptake of micro-nutrients and some positive and negative effects on susceptibility to diseases. These effects were specific to herbicide use with glyphosate-tolerant crops. Based on this, it was not possible to draw general conclusions for developing protocols for post-release monitoring of environmental effect