g15.
Doug Gurian-Sherman, “Failure to Yield: Evaluating the Performance of Genetically Engineered Crops”, Union of Concerned Scientists, April 2009. Another illustration of this comes from a study of results in North America, which found that, after the switch to genetically modified varieties, the yield of soya fell by between 1 percent and 19 percent, with a typical reduction of about 10 percent (the yield from some maize, engineered for pest resistance, rose very slightly, but in the case of oilseed rape, the study found a 7.5 percent reduction): Hugh Warwick and Gundula Meziani, “Seeds of Doubt: North American Farmers’ Experience of GM Crops”, The Soil Association, 2003, chapter 4, available at http://tinyurl.com/nk9ns3n . See also Ricarda A Steinbrecher and Antje Lorch, “Feed the World?”, The Ecologist, November 2008, pp 18–20.