36. Genetically Modified (GM) Crops: a Note of Caution


According to Owen Paterson, the Minister in charge of DEFRA, GM foods are the best thing since sliced bread(1). He claims that Europe is missing out because less than 0.1% of the global cultivation of GM crops is grown in the EU. He argues that Europe is missing out while the rest of the world is forging ahead and benefitting from the GM technology. His ambition is that the UK should play a leading role in pushing ahead with the technology in Europe.

Therefore it is extremely relevant that a study conducted in New Zealand at the University of Canterbury has compared crop production in the USA where there is extensive use of GM crops with Europe where as Paterson has emphasised there is negligible use of the technology (2).

The research team set out to answer the following questions:

  • Is the the biotechnology chosen by the American farmer successful in optimizing yield?
  • Is the American agro ecosystem achieving greater outcomes in lessening its impact on the environment, as might be indicated in reducing use of inputs such as pesticides?
  • Is the social context created through policies on innovation and intellectual property (IP), and government subsidy programmes delivering greater resilience?
  • Are the prevailing policies adequate to meet future human resource needs?

In North America, the adoption of GM soybeans, maize, rapeseed and cotton has almost reached saturation. According to industry sources, GM maize reached 88% by 2011, GM soybeans 94% by 2011 and GM cotton 94% by 2012 in the USA. The proportion of GM rapeseed reached 82% in the USA by 2007 and 95% in Canada by 2009.


The introduction of GM crops commenced after 1985 and so the information in Table 1 enables a comparison to made of the impact of the technology. It is evident that in with both maize in USA and rapeseed in Canada there has been an increase in yields after the GM crops were introduced. However over the same periods in Europe there were also substantial increases in yields but this happened without GM crops. In fact the yields of maize in Europe were lower in the earlier period but were virtually identical in the second period. This means that there had been a greater improvement in Europe in the absence of the GM technology. For rapeseed production the output in Canada was much lower than in Europe but the proportional increase in Europe (48%) was slightly greater than in Canada (39%).

TABLE 1 Average yields, tonnes/hectare

EUROPE 4.9 8.3


With wheat the yields have been consistently higher in W. Europe than in the United States, on average by 3.14 tonnes/hectare from 1961 to 2011. While wheat yields significantly increased over time in both countries, the increase per annum was significantly higher in W. Europe than in the USA. GM wheat is not used in either region which confirms that yield gains are not dependent on GM biotechnologies and that the combination of biotechnologies used by W. Europe is demonstrating greater productivity than the combination used in the USA.


A comparison between pesticide usage between 1995 and 2007 shows that in the USA, chemical insecticide usage had fallen by 15% but that herbicide usage had increased by 8%. Over the same period in France there had been reductions in both herbicide (to 94% of 1995 levels) and chemical insecticide (to 24% of 1995 levels) use by 2007.However 2 years later the herbicide use was down to 82%, and insecticide use was down to 12% of the 1995 levels. Similar trends were seen in Germany and Switzerland. So clearly there had been much greater progress achieved in Europe despite the absence of any GM crops.

It was concluded that GM crops have maintained or increased US pesticide use relative to equally advanced competitors. Furthermore the pattern and quantities unique to the use of GM-glyphosate-tolerant crops has been responsible for the selection of glyphosate-tolerant weeds, with estimates of resistant weeds on between 6 and 40 million hectares in the United States.


  1. https://www.gov.uk/government/speeches/rt-hon-owen-paterson-mp-speech-to-rothamsted-research
  2. J A Heinemann et al (2013) International Journal of Agricultural Sustainability DOI:10.1080/14735903.2013.806408

To be Continued.

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