Genetic Modification
The development of genetically modified food is the most controversial development in farming and the food industry for centuries. Throughout history man has developed new methods of farming and new types of food but GM food represents a revolutionary change compared to the evolutionary process that has ruled up to now.
Scientists have developed methods of manipulating DNA, by transferring it from one organism to another. Characteristics such as the height to which wheat grows are encoded into molecules of DNA of all living things. DNA consists of chromosomes that have series of genes; these genes are inherited through the generations. A gene that encodes a desirable trait can be copied and transferred into another organism and this is called genetic modification. There two main types of GM crops being grown at the moment. The first can tolerate herbicides that wipe out other plants and the second type is modified to produce toxin that kills pest that feed on it.
At present around 25% of the world’s crops are lost to pesticides and diseases through insect attack which is enough to feed over one billion people. However with Genetic Modification you can stop this as for example with the Bt maize, the maize plant modified with poisoning producing genes taken from the bacterium thuringiensis is able to resist the corn borer insect which can destroy up to 20% of a crop. Weeds are also a threat to food crops, even though there is no problem with the amount of herbicides, there is a limit to when you can use them. As with ‘broad spectrum’ herbicides you can only spray before the crop has emerged from the soil and then you spray again with selective herbicide when the crops start to emerge. However, crops that have been genetically modified to tolerate the ‘broad spectrum’ herbicide can be sprayed at the optimal time at which to spray and therefore the fewer sprays can reduce number of tractor trips across the field and save energy. Since weeds compete for water, sunlight and soil nutrients, such GM crops might produce higher yields.
