Pesticide resistant rape plants
Scientists have transferred a gene to the rape plant which enables the plant to resist a certain pesticide. When the farmer sprays his genetically modified rape crop with pesticides, he or she can destroy most of the pests without killing the rape plants.
- The farmer can grow a larger crop because it is easier to fight pests.
- In some cases the farmer can use a more environmentally friendly crop spray.
- The farmer can also protect the environment by using less crop spray.
- Genes from the genetically modified rape crop could be transferred to the pests. The pests then become resistant to the crop spray and the crop spraying becomes useless.
- Rape plants can pollinate weeds - for example navew which is found in rape fields. When rape plants pollinate the navew their genes are transferred. The navew then acquires pesticide resistance.
Corn, soya beans and sugar cane have also been genetically modified by scientists so they are able to tolerate crop spray.
Insecticide sweet corn
Scientists have genetically modified sweet corn so that it produces a poison which kills harmful insects. This means the farmer no longer needs to fight insects withinsecticides. The genetically modified corn is called Bt-corn, because the insect-killing gene in the plant comes from the bacteriaBacillus thuringiensis.
- The farmer no longer has to use insecticide to kill insects, so the surrounding environment is no longer exposed to large amounts of harmful insecticide.
- The farmer no longer needs to walk around with a drum of toxic spray wearing a mask and protective clothing.
- This type of genetically modified corn will poison the insects over a longer period than the farmer who would spray the crops once or twice. In this way the insects can become accustomed (or resistant) to the poison. If that happens both crop spraying and the use of genetically modified Bt-corn become ineffective.
- A variety of insects are at risk of being killed. It might be predatory insects that eat the harmful ones or, perhaps attractive insects such as butterflies. In the USA, where Bt-corn is used a great deal there is much debate over the harmful effects of Bt-corn on the beautiful Monarch butterfly.
Cotton and potatoes are other examples of plants that scientists have , genetically modified to produce insecticide.
Golden rice is genetically modified rice that now contains a large amount of A-vitamins. Or more correctly, the rice contains the elementbeta-carotene which is converted in the body into Vitamin-A. So when you eat golden rice, you get more vitamin A.
Beta-carotene gives carrots their orange colour and is the reason why genetically modified rice is golden. For the golden rice to make beta-carotene three new genes are implanted: two from daffodils and the third from a bacterium.
- The rice can be considered a particular advantage to poor people in underdeveloped countries. They eat only an extremely limited diet lacking in the essential bodily vitamins. The consequences of this restricted diet causes many people to die or become blind. This is particularly true in areas of Asia, where most of the population live on rice from morning to evening.
- Critics fear that poor people in underdeveloped countries are becoming too dependent on the rich western world. Usually, it is the large private companies in the West that have the means to develop genetically modified plants. By making the plants sterile these large companies can prevent farmers from growing plant-seed for the following year - forcing them to buy new rice from the companies.
- Some opposers of genetic modification see the "golden rice" as a method of making genetic engineering more widely accepted. Opponents fear that companies will go on to develop other genetically modified plants from which they can make a profit. A situation could develop where the large companies own the rights to all the good crops.
Long-lasting, genetically modified tomatoes came on to the market in 1994 and were the first genetically modified food available to consumers. The genetically modified tomato produces less of the substance that causes tomatoes to rot, so remains firm and fresh for a long time.
- Because the GM tomatoes can remain fresh longer they can be allowed to ripen in the sun before picking - resulting in a better tasting tomato.
- GM tomatoes can tolerate a lengthier transport time. This means that market gardens can avoid picking tomatoes while they are green in order that they will tolerate the transport.
- The producers also have the advantage that all the tomatoes can be harvested simultaneously.
- Scientists today can genetically modify tomatoes without inserting genes for antibiotic resistance. However the first genetically modified tomatoes contained genes that made them resistant to antibiotics. Doctors and vets use antibiotics to fight infections. These genes spread to animals and people, doctors would have difficulties fighting infectious diseases.
Strawberries, pineapples, sweet peppers and bananas have all been genetically modified by scientists to remain fresh for longer.