Most (GM crops) have been engineered to resist harmful insects and to withstand glyphosate, a type of weedkiller. This enables farmers to achieve high yields without employing costly practices such as frequent ploughing and crop rotation.
However, these may prove to be transient gains:
Insects are evolving new ways of overcoming the crops’ artificial defences. As GM crops have become more popular, so has the weedkiller they are designed to tolerate, leading to the emergence of resistant weeds. This has forced some farmers to fall back on old methods they thought they were avoiding when they bought expensive GM seed. Even growers of conventional crops may no longer be able to rely on a chemical that has been in use since the 1970s.
The biotechnology industry is fighting back with more advanced crop strains, some of which can be concurrently treated with multiple weedkillers. That, it is argued, will make natural resistance less likely to emerge. But many experts are sceptical. Monsanto used to argue that its original GM crop was unlikely to encourage weedkiller resistance, until the weeds proved it wrong. Scientists risk getting into an arms race against nature, for which farmers will be forced to pay without receiving any long-term benefit in return . . .
Scientists should acknowledge the limits of their understanding, and proceed with caution. By shunning GM crops, Europe is foregoing gains that US farmers have enjoyed since the 1990s. If this has prevented ecological damage that could permanently depress yields, it will have been a small price to pay.
Read the editorial here: http://www.ft.com/cms/s/0/73b3c1dc-f08d-11e2-929c-00144feabdc0.html#ixzz2aQd4jycz – free registration.
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