GM Crops
Genetically modified organisms, or GMOs, are plants or animals that have been altered by DNA technology. GM crops are widely grown in the USA and many parts of the developing world, but public opposition has resulted in much more restricted use in the EU. Although there have been trials of GM crops in the UK, none is currently being grown commercially. Government consultations have addressed the issue of co-existence with conventional and organic crops, with a view to allowing cultivation of certain GM crops within the next few years.
What are the issues surrounding GM?
Recent articles on GM from Biologist magazine
Plant breeding has traditionally taken place by cross-breeding related species of plants, and more recently by chemical or radiation treatment of seeds to induce genetic changes, followed by selection of plants with the desired characteristics, a slow and unreliable process. Genetic modification allows the directed insertion of a specific characteristic into a plant or animal, and so is a powerful tool for creating new varieties.
Most GM crops currently under production have been engineered either for resistance to herbicides or pesticides, or to contain the Bt insecticide gene. GM can also be used to increase the nutritional content of plants: for example, 'golden rice' produces beta-carotene, the precursor to vitamin A. GM can also be used to develop plants more resistant to environmental stresses such as drought and salty soil than conventional varieties.
Much research is currently in progress to develop GM plants that produce drugs, a process known as pharming. For example, tobacco plants have been engineered to produce cyanovirin N, which helps prevent infection by HIV.
What are the issues surrounding GM?
- Increased yields Common GM traits include herbicide and pesticide resistance, which result in increased yields because the farmer can kill any competing weeds or pests without harming the crop. Plants can also be modified to show increased resistance to environmental stresses such as drought. Higher and more guaranteed yields are particularly important in developing countries, where crop failure can have devastating effects. However, there is an argument that many of the problems with food supply in the developing world are political and economic rather than environmental, and that GM crops will do little to alleviate this.
- Cross-fertilisation Early trials of GM oil-seed rape in the UK resulted in the detection of the genetic modification in conventionally grown crops harvested from neighbouring fields. The issue of cross-fertilisation is not a problem for plants such as potatoes and sugar beet that do not produce pollen, but pollination of related plants nearby is highly probable in the case of plants such as oil-seed rape. This can be reduced by a number of measures, such as separation zones around GM crops, cooperation between farmers to plant crops that will flower at different times, and PCR tests of neighbouring crops to detect contamination. As all GM crops that would be grown in the UK have already been subjected to stringent safety tests, the possibility of a low degree of contamination does not pose any risk to the public. The acceptable level of contamination by GM crops has been set at 0.9% in the UK. For pharmed crops the avoidance of cross-fertilisation is very important, and stringent guidelines will be needed before these crops can be cultivated commercially. It is likely that pharming will be confined to non-food crops such as tobacco, so as to avoid contamination of the food chain, and possible that physical containment will also be used.
- The environment GM crops that have a reduced requirement for insecticides or fertilisers can have a positive impact on biodiversity. A recent comparison of maize and cotton producing the Bt insecticide with conventional and organic crops showed that biodiversity in the GM fields was considerably higher than in conventionally farmed fields that were sprayed with insecticide, although slightly lower than around organic crops. Increased yields resulting from GM crops can also have environmental benefits, as less land needs to be cultivated to obtain the same amount of food. However, there is concern that the cultivation of herbicide-resistant crops will not necessarily reduce the levels of herbicide used, and also that widespread farming of GM crops will result in a predominance of large monocultures and a negative impact on biodiversity. In South America the cultivation of GM soya has been associated with rainforest destruction.
- Health benefits The use of the Bt insecticide gene in cotton is said to have had health benefits in China and India due to the reduced need for neurotoxic insecticides (although some question the data behind this assertion). GM has the potential to improve the nutritional content of many plants, such as 'golden rice' with increased beta-carotene to combat vitamin A deficiency. Others argue that a balanced diet should be able to provide adequate nutrition without the need for enhanced crops, and nutritional deficiencies in the developing world could be addressed by improvements in cultivation and supply of conventional crops. The cheap supply of large quantities of drugs by pharming has enormous potential medical benefits, especially in the developing world.
- Economics GM technology is in many cases dominated by large multinational corporations. There is concern about the consequences of the level of control exerted by these companies. Herbicide-resistant plants are supplied in conjunction with a patented herbicide, and 'terminator technology' to make plants that produce sterile seeds prevents the traditional farming practice of saving and re-planting seeds from the previous year's crop. This economic control applies to a high proportion of GM crops, but golden rice has been granted a free licence for humanitarian purposes.
- Safety There is much public concern about the possible danger of consuming foods derived from plants with genetic modifications. In practice most processed products derived from GM crops do not contain DNA and are identical to the same product derived from a conventional variety. Although it is impossible to prove conclusively that there are no long-term health risks associated with the consumption of GM-derived foods, widespread consumption in the USA for a number of years has had no effect on public health. EU regulations impose stringent safety tests on all new GM crops.
We support the use of GM technology in principle, when properly regulated and tested case-by-case. We feel that the cultivation of certain GM crops in the UK could have a positive impact on the environment and that farmers should have the opportunity to use this technology if they wish to do so.
We believe that it is important to assess new crops carefully for safety, and to consider issues of crop separation and cultivation methods, such as use of herbicides, case-by-case. It is necessary to consider all decisions in the light of the best scientific evidence available.
We consider that the responsibility for infringements of GM regulations lies primarily with the farmer and that liability measures should be in place.
We understand that there is considerable public unease surrounding the issue of GM, and believe that the government should do everything possible to allay this unease by seeking to understand and address public concerns, maintaining effective communication with the public and making sure that sufficient regulations are in place and enforced.
Many concerns about the impact of GM technology, such as the dominance of multinational corporations, industrialisation of food production and the environmental consequences of large monocultures, are issues that affect modern agriculture in general and should be considered separately from the use of GM crops per se.
Recent consultation responses
We responded to the following consultation on GM legislation:
20 October 2006
Managing the coexistence of GM and non-GM crops in England
A response to the Department for Environment, Food and Rural Affairs
Recent articles on GM from the Biologist magazine
August 2007
GM crops - good or bad for Africa?
Jennifer Thomson
February 2007
Biofuels - is there a role for GM?
Derek Burke
December 2005
Substantial Equivalence - who needs it anyway?
Alan D B Malcolm
Exploring attitudes to GM Food. Food Standards Agency November 2009
Eating the planet? Friends of the Earth and Compassion in World Farming, November 2009
Reaping the benefits Royal Society, October 2009
Food Ethics Council commentary on “Reaping the benefits” October 2009
Making sense of GM Sense about Science, February 2009
IAASTD report (International Assessment of Agricultural Knowledge, Science and Technology for Development) April 2008
Biotechnology research archive STEPS Centre
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