The Impact of GMOs
Insecticide:
In the United States, the use of Bt crops has lead to a decrease in the use of insecticides. The fact that Bt crops have a built in resistance to certain pests means that farmers do not have to use as much pesticide for those affected insects. According from a report from the United States Department of Agriculture, only 9% of U.S corn farmers used insecticides in 2010.
A different study showed that Bt crops in the U.S have reduced insecticide application by approximately 56 million kilograms, or 123
million pounds.
Herbicide:
HT crops are modified to be able to withstand certain herbicides, such as glyphosphate, so that weeds can be easily killed without harming the crops. Glyphosphate can be used as a substitute for more toxic herbicides, although there is some concern over possible over reliance and over use. While some sources say that HT crops have only changed the type of herbicide used, other studies have indicated that the use of HT crops have actually increased the use herbicides. A study posted in Environmental Sciences Europe has shown that from 1996 - 2011, there has been a 239 million kilogram increase in herbicides in the United States.
Resistant insects or weeds:
As with most pesticides, there is a chance of resistance. Insects can evolve resistance to pesticides and weeds can evolve resistance to herbicides. Pest populations can develop resistance by natural selection. While there have been [procedures] used to slow the rate of evolution, there has been evidence of HT resistance in 14 weeds and biotypes in the U.S, as well as resistance to Bt.
Antibiotic resistance:
Biotechnologists use antibiotic resistance genes as selectable markers when inserting new genes into plants. In the early stages of the process scientists do not know if the target plant will incorporate the new gene into its genome. By attaching the desired gene to an antibiotic resistance gene the new GM plant can be tested by growing it in a solution containing the corresponding antibiotic. If the plant survives scientists know that it has taken up the antibiotic resistance gene along with the desired gene. However, bacteria can develop resistance to antibiotics by creating antibiotic resistance genes through natural mutation. There is concern that bacteria living in the guts of humans and animals could pick up an antibiotic resistance gene from a GM plant before the DNA becomes completely digested, though it is an extremely low risk.
Increased Toxicity:
There is a low risk of other genes in the plant becoming damaged during the insertion process, causing the plant to alter its production of toxins. Making sure that this does not happen is an essential part of the safety test that GMO crops go through.
Gene transfer:
Modified genes can pass onto other plant species from the pollen of modified crops. Gaining these traits can lead to some plants gaining an advantage and spreading.
Other potential effects to environment:
GMOs may have an unintended effect on nontarget species within the same ecosystem. For example, Bt crops only targets a few insect species, but other insect species may gain an advantage from the decreased competition.
Crop yield:
Bt crops have shown a higher net return due to reduced loss of usable crops from insects. Crops with stacked genes, multiple modified genes, show higher yields than just single gene or conventional farming.
Potential of decreased Nutritional Value:
A GM plant has the possibility of having lower nutritional quality than its traditional counterpart by making nutrients unavailable or indigestible to humans
Potential for increased nutritional value:
There is potential for GMO crops to be modified to have higher nutritional content. There is already research being done to create rice rich in beta carotene, which is converted by the body into vitamin A.
Potential for adapting crops for environment:
There is also the the potential for crops to be modified to better suit different climates or conditions, such as drought.
In the United States, the use of Bt crops has lead to a decrease in the use of insecticides. The fact that Bt crops have a built in resistance to certain pests means that farmers do not have to use as much pesticide for those affected insects. According from a report from the United States Department of Agriculture, only 9% of U.S corn farmers used insecticides in 2010.
A different study showed that Bt crops in the U.S have reduced insecticide application by approximately 56 million kilograms, or 123
million pounds.
Herbicide:
HT crops are modified to be able to withstand certain herbicides, such as glyphosphate, so that weeds can be easily killed without harming the crops. Glyphosphate can be used as a substitute for more toxic herbicides, although there is some concern over possible over reliance and over use. While some sources say that HT crops have only changed the type of herbicide used, other studies have indicated that the use of HT crops have actually increased the use herbicides. A study posted in Environmental Sciences Europe has shown that from 1996 - 2011, there has been a 239 million kilogram increase in herbicides in the United States.
Resistant insects or weeds:
As with most pesticides, there is a chance of resistance. Insects can evolve resistance to pesticides and weeds can evolve resistance to herbicides. Pest populations can develop resistance by natural selection. While there have been [procedures] used to slow the rate of evolution, there has been evidence of HT resistance in 14 weeds and biotypes in the U.S, as well as resistance to Bt.
Antibiotic resistance:
Biotechnologists use antibiotic resistance genes as selectable markers when inserting new genes into plants. In the early stages of the process scientists do not know if the target plant will incorporate the new gene into its genome. By attaching the desired gene to an antibiotic resistance gene the new GM plant can be tested by growing it in a solution containing the corresponding antibiotic. If the plant survives scientists know that it has taken up the antibiotic resistance gene along with the desired gene. However, bacteria can develop resistance to antibiotics by creating antibiotic resistance genes through natural mutation. There is concern that bacteria living in the guts of humans and animals could pick up an antibiotic resistance gene from a GM plant before the DNA becomes completely digested, though it is an extremely low risk.
Increased Toxicity:
There is a low risk of other genes in the plant becoming damaged during the insertion process, causing the plant to alter its production of toxins. Making sure that this does not happen is an essential part of the safety test that GMO crops go through.
Gene transfer:
Modified genes can pass onto other plant species from the pollen of modified crops. Gaining these traits can lead to some plants gaining an advantage and spreading.
Other potential effects to environment:
GMOs may have an unintended effect on nontarget species within the same ecosystem. For example, Bt crops only targets a few insect species, but other insect species may gain an advantage from the decreased competition.
Crop yield:
Bt crops have shown a higher net return due to reduced loss of usable crops from insects. Crops with stacked genes, multiple modified genes, show higher yields than just single gene or conventional farming.
Potential of decreased Nutritional Value:
A GM plant has the possibility of having lower nutritional quality than its traditional counterpart by making nutrients unavailable or indigestible to humans
Potential for increased nutritional value:
There is potential for GMO crops to be modified to have higher nutritional content. There is already research being done to create rice rich in beta carotene, which is converted by the body into vitamin A.
Potential for adapting crops for environment:
There is also the the potential for crops to be modified to better suit different climates or conditions, such as drought.