The GM Food Debate

Many people want farmers either to use fewer chemicals or chemicals which are less harmful to the environment. Much of current GM technology is aimed at achieving this. With herbicide tolerant crops just one or two applications of glyphosate can often control weeds, whereas with non-GM crops repeated applications of a range of selective, 'narrow spectrum' herbicides may be needed. Insect resistant crops can lead to significant reductions in the use of insecticides. Corn borers enter the maize stalk and eat the plant from the inside. To kill them conventionally can take up to six sprays. GM maize protects itself against the corn borer and usually only one application of insecticide is needed to control other pests.

Making crops resistant to insects and diseases and reducing weeds should lead to fewer crop losses. For example, worldwide 7% of the annual maize harvest is destroyed by the European corn borer, up to 20% in some areas. If Bt maize delivers its promise, maize yields in Europe and the US together could increase by 7-10 million tonnes.

Fewer chemicals are used on herbicide tolerant and insect resistant GM crops. This in turn brings savings in the energy which would have been used to produce and transport those chemicals. There are potential energy savings on the farm too; the use of tractor diesel is reduced as fewer sprayings means fewer trips across the fields. More efficient processing saves energy. The GM tomato grown in the US stays firmer for longer which means less is lost during processing. Another possible future development is GM wheat modified to make it easier to mill.

In developing countries yields of almost all crops are significantly lower due to greater problems with insects, weeds and diseases. There are 100 million people starving and 800 million people hungry in the world today and the global requirement for food could double in the next two generations. The pressure to produce food in, and for, the developing countries is mounting.

Supporters of GM technology claim that it could be used to help feed the world. As well as increased yields, future applications could enable crops to be grown in less fertile areas. Drought resistance could be built into plants to enable them to grow in arid conditions, whilst plants made resistant to frost could grow in colder climates. Critics of the technology however have their doubts. One concern is whether or not those in the developing countries will have access to the technology. Some of the large corporations who own the technology have freely donated certain applications to developing countries.

With the undoubted benefits of GM crops come possible risks. The more frequently a pesticide is used on successive crops, the more likely it is that resistance to it will emerge in the weeds and insects which it is designed to kill. The concern with GM crops is that increased use of a single herbicide on successive crops will lead to more weeds becoming resistant. Similarly, insects will develop resistant to toxins such as the Bt protein.

There is also the chance that genes from GM crops may be accidentally transferred to non-GM crops. The chances of this are increased if the two crops are grown adjacent to each other. 'Organic' crops will lose their status if they do not remain completely free of all GM genes.

People are becoming increasingly concerned that man's interaction with the environment has led to a reduction in the diversity of our flora and fauna. Some believe that GM technology could lead to a loss of biodiversity. In some countries, single crops are grown over a very wide area. These mono-cultures threaten biodiversity. The less successful crops are not grown so that available varieties are reduced. This also leads to a loss of the flora and fauna which thrives on them.