Crops are genetically modified to give them characteristics that would be slow or impossible to achieve by selective breeding.Aims of GM crops
• Pest resistance: Bt crops produce a toxin that kills insect pests, so they need less insecticide spraying.
• Herbicide tolerance: farmers can spray fields to kill weeds without harming the crop.
• Disease resistance: for example papaya modified to resist papaya ringspot virus.
• Tolerance of drought or salty soils, allowing crops to grow on poor land.
• Improved nutrition: Golden Rice has been modified to produce beta-carotene, which the body converts into vitamin A. Vitamin A deficiency causes blindness in many children where rice is the main food.
• Longer shelf life and less waste.Benefits
Higher yields per hectare mean less land is needed to grow the same amount of food, which may help global food security. Less spraying reduces costs, fuel use and harm to farm workers and non-target wildlife.Concerns
• Widespread planting of Bt crops selects for insect pests that are resistant to the toxin, which then evolve and spread.
• New genes may spread by pollen to wild relatives, called gene flow, possibly producing herbicide-tolerant weeds.
• Large areas of one crop may reduce biodiversity.
• Seed is often patented and expensive, so poorer farmers may depend on large companies and may have to buy new seed each year.
• Pest resistance: Bt crops produce a toxin that kills insect pests, so they need less insecticide spraying.
• Herbicide tolerance: farmers can spray fields to kill weeds without harming the crop.
• Disease resistance: for example papaya modified to resist papaya ringspot virus.
• Tolerance of drought or salty soils, allowing crops to grow on poor land.
• Improved nutrition: Golden Rice has been modified to produce beta-carotene, which the body converts into vitamin A. Vitamin A deficiency causes blindness in many children where rice is the main food.
• Longer shelf life and less waste.Benefits
Higher yields per hectare mean less land is needed to grow the same amount of food, which may help global food security. Less spraying reduces costs, fuel use and harm to farm workers and non-target wildlife.Concerns
• Widespread planting of Bt crops selects for insect pests that are resistant to the toxin, which then evolve and spread.
• New genes may spread by pollen to wild relatives, called gene flow, possibly producing herbicide-tolerant weeds.
• Large areas of one crop may reduce biodiversity.
• Seed is often patented and expensive, so poorer farmers may depend on large companies and may have to buy new seed each year.