[holding answer 16 July 2008]: In the Daily Mail on 18 December 2007, the then Government Chief Scientific Adviser Sir David King was reported as acknowledging that he had made an honest mistake about the push-pull system of maize production. The technique, which has been developed by Rothamsted Research and local research institutes in Africa, does not currently involve genetic modification of the crops. Under the technique, repellent crops are planted between the rows of maize to drive the stemborer pests away from the maize (“push”) in combination with plants around the field that attract stemborers away from the maize (“pull”). Rothamsted Research reports that trials in Kenya and Uganda have helped participating farmers increase their maize yields by 20 to 50 per cent.
One of the “push” plants also controls a parasitic plant, the African witchweed, that otherwise causes even greater crop losses. The genetic basis of the mechanism is being studied by Rothamsted Research and its African collaborators under new funding from the Department for International Development and the Biotechnology and Biological Sciences Research Council.