Lowering of environmental pollution through plant protection agents
Reducing the use of pollutive plant protection agents is one of the major aims of the production of genetically modified crops. In order to achieve this aim as well as an increase in crop yields, crops resistant to herbicides, fungicides and insecticides are being created. However, lowering environmental pollution through a reduced use of plant protection agents on these crops is not successful for all puproses.
According to a meta-analysis of the year 2014 by Qaim and Klümper at the University of Göttingen the cultivation of genetically modified crops can increase crop yields and lower the use of plant protection agents. Nevertheless, these effects vary regionally (the positive effect turned out to be higher in countries of the global south) and primarily apply to insect-resistant varieties and less so to herbicide- and fungicide-resistant plants.
Qaim, M. / Klümper, W. (2014): A Meta-Analysis of the Impacts of Genetically Modified Crops. In: PLoS One 9(11), doi: 10.1371/journal.pone.0111629 PMCID: PMC4218791 Online Version
An analysis by the New York Times revealed in 2016 that the cultivation of genetically modified crops reduced the use of insecticides and fungicides successfully, but not that of herbicides. The study compared the application of pesticides (insecticides, fungicides and herbicides) in the USA and in France within 20 years. It showed that the use of herbicides in France had diminished despite the waiving of genetic engineering while it had increased steadily in the US for the last 20 years and even considerably since 2008. One cause of the intensified application of herbicides in connection with genetically modified crops is the development of weeds that have become resistant to herbicides. In many cases, weeds had become resistant to the broad-spectrum herbicide glyphosate, the worldwide bestseller for agriculture, which is ordinarily used on large surface areas.
Hakim, D. (2016): Doubts About the Promised Bounty of Genetically Modified Crops. In: The New York Times (29. Oktober 2016) Online Version (Englisch)
Further information on pesticide use in the USA and herbicide resistances: :
Fernandez-Cornejo, J. / Nehring, R. / Osteen, C. / Wechsler, S. / Mart, A. / Vialou, A. (2014): Pesticide Use in U.S. Agriculture: 21 Selected Crops, 1960-2008. U.S. Department of Agriculture, Economic Research Service (Economic Information Bulletin 124) Online Version
Perry, E. D. / Ciliberto, F. / Hennessy, D. A. / Moschini, G.-C. (2016): Genetically engineered crops and pesticide use in U.S. maize and soybeans. In: Science Advances 2. doi: 10.1126/sciadv.1600850 Online Version
A study by the US National Academics of Sciences of the year 2016 equally stresses the need for a carefully differentiated analysis. It cannot be inferred that a general reduction of environmental pollution can be achieved solely through cultivation of genetically modified crops. Positive effects did occur, but it is necessary to consider local site conditions and to distinguish between different types of pesticide, i.e. between fungicides, herbicides and insecticides.