Friday 30 March, 2001
GM Crop Caution
Six years ago, farm scale planting of genetically engineered crops began. And the adoption rate has been explosive - last year, an area twice that of the UK was seeded with transgenic varieties.
Whilst many farmers and companies are happy with their increased profits, not so happy are many consumers who are uneasy about the safety of GM food.
In the second part of Seeds Of Contention, Andrew Luck-Baker examines the debates about whether GM crops pose a threat to the environment, or whether in fact they offer a greener kind of crop growing compared to the agriculture of the 20th century.
Six years ago, the topic of plants with genes from other species added to them was an obscure one. Today it has arguably become the most controversial technology of our time.
Not since nuclear power, has a technology come upon the scene to stir up so many environmental and civil society groups. At a meeting of British organic farmers, it was even the subject of a Royal speech:
'Personally I don't think I don't think it is right to tamper with the building blocks of life. I also regard the technology as unproven with the potential to cause serious and possibly irreversible damage to wildlife and the environment'.
However, The Prince of Wales view isn't the only environmental perspective on genetically engineered crops. According to the Biotechnology Industry Organisation, GM crops offer a cleaner kind of agriculture than the intensified farming of the 20th century – less pesticide spraying, fewer and safer herbicides, greater water efficiency to name a few advantages.
But what of the risks? If there are any, are they worth taking to reap the benefits that GM proponents claim?
Gene Flow
One of the main issues is something called gene flow. All the crops grown by farmers around the world were originally bred from wild plant species.
Although crop plants are now in many ways different from their natural ancestors, they still have the ability to interbreed. So pollen from transgenic crops, such as maize and sugarbeet, does have the potential to fertilise their wild relatives and introduce the added DNA into their genetic make-ups - genes which might be from other plants or bacteria, or possibly animals.
So how much do we know about gene flow? Sue Mayer of the pressure group, Genewatch UK comments:
'In the early 1990s we really were very uncertain about whether gene flow between oil seed rape or sugar beet and its wild relatives would take place. We now are certain that it will do. We don't know what the frequency is and we are not really sure what the importance of that will be … But I think that we can say that there are real concerns.'
Genetic Pollution
The opponents of plant genetic engineering have dubbed gene flow, genetic pollution - raising the spectre of wild plants across landscapes taking on novel characteristics. Growing where they don't normally, disrupting natural food chains, unbalancing whole ecosystems.
According to Guy Poppy, an ecologist at the UK's Southampton University, that's most likely to be a gross exaggeration. He says that if even genes do move from crops to wild plants, they won't necessarily establish themselves permanently in those natural populations.
'As people know when they look at human populations, genes tend to have to have an advantage before they spread. If you are talking about spreading where you don't want it, in the case of say herbicide tolerance, its hard to see it spreading into nature reserves because this advantage isn't going to be there.'
| 'Genes will flow but that doesn't necessarily mean that you get genetic pollution.' |
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Single Gene Traits
But Guy Poppy agrees it's impossible to be sure whether every added gene that flows into wild plants will vanish within a plant generation or two. The two mostly widely engineered traits at the moment are herbicide tolerance and pest resistance, specifically against caterpillars or certain beetles.
They're the result of transferring single genes into plants. But in the future, genetic engineers hope to produce crops that, as examples, thrive in salty soils or that can tough out droughts.
LaReesa Wolfenbarger is an ecologist in the US, she explains the crops potential:
| 'We're really dealing with this very low risk, but very high effect kind of trade off… But as we start experimenting with other types of traits that potential may change.' |
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Transgenic Distrust
So we really don't know whether gene flow will cause problems. Consequently governments around the world have different policies towards the concerns. European Union countries have a ban on commercial growing in place for another 18 months at least - whereas in North America, ecological questions have not been deemed sufficient to stop farmers choosing to plant GM Soya, cotton, potatoes and maize.
The widespread distrust of transgenic crops and foods in European Union countries has also led to the compulsory labelling of foods containing transgenic products and to many European food manufacturers demanding only non-GM produce from overseas suppliers. That situation shows signs of blunting some of the initial enthusiasm, on the part of some American Soya and corn growers for GM varieties.
There are also suggestions that the rate of adoption of genetically engineered crops may start to plateau in North America - there are moratoriums on commercial planting in the European Union - an indefinite ban on any kind GM maize in Mexico - and increasingly other countries around the world are taking a cautious approach.
But if there is a coherent message to come out of all of these approaches, it's that it's impossible to generalise and have much certainty either way about the safety of the crops. The balance of risks and benefits are going to vary from crop to crop, from engineered trait to trait, from climate to climate and from ecosystem to ecosystem.
|  |  | | | Seeds Of Contention |  |
| | Broadcast over three weeks, Seeds Of Contention sets out to explore the issues at the heart of the GM crop controversy.
Part one examines the arguments that GM crops are going to be vital in ensuring food security in the developing world, as the global population rises.
Part two looks at the debates about whether GM crops pose a threat to the environment, or whether in fact they offer a greener kind of crop growing compared to the agriculture of the 20th century.
Part three investigates whether there are dangers for farmers from the degree of control, ownership and influence multinational companies have over GM technology.
To find out when you can hear the series in your region, click on our schedule pages here. |
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