Genetically modified crops are plants used in farming. Their DNA has been changed using special scientific methods. Usually, these changes help plants gain traits that they naturally do not have. By 2015, 26 types of plants had been genetically modified and approved for use in at least one country. Most of these plants have genes that help them survive when chemicals called herbicides are used or when insects try to harm them. Other traits include protection from viruses, slower ripening, different flower colors, or changes in their nutritional content. In 2014, 28 countries grew genetically modified crops, and 39 countries imported them but did not grow them.

Background

Rules about using genetically modified (GM) crops for business are mostly decided by each country. To grow GM crops, they must pass environmental checks to be legally planted. Different permission is usually needed to use GM crops in food for people or as animal feed.

GM crops were first grown on a large scale in 1996 in the United States, China, Argentina, Canada, Australia, and Mexico. Some countries have allowed GM crops but have not planted them because of public concerns or more government rules. These countries may still import GM foods for people to eat. For example, Japan allows importing GM foods but does not grow GM crops. The European Union controls the import of GM foods, while each country in the EU decides if GM crops can be planted. In the United States, different government groups handle rules for planting (USDA, EPA) and for food safety (FDA).

Two types of GM crops have been approved for food use in some countries but are not allowed to be planted. A GM melon designed to stay fresh longer was approved in 1999, and a GM wheat resistant to weed killers was approved in 2004.

Genetically modified crops cultivated in 2014

In 2014, 181.5 million hectares of genetically modified crops were grown in 28 countries. Half of all genetically modified crops planted were soybeans, which were either made resistant to herbicides or able to survive insect attacks. Eleven countries grew modified soybeans, with the United States, Brazil, and Argentina growing 90% of the total soybean area. Of the 111 million hectares of soybean grown worldwide in 2014, 82% was genetically modified. Seventeen countries grew 55.2 million hectares of genetically modified maize, and fifteen countries grew 23.9 million hectares of genetically modified cotton. Nine million hectares of genetically modified canola were grown, with 8 million of those in Canada. Other genetically modified crops grown in 2014 included alfalfa (862,000 hectares), sugar beet (494,000 hectares), and papaya (7,475 hectares). In Bangladesh, genetically modified eggplant was grown commercially for the first time on 12 hectares.

Most genetically modified crops were made to resist specific herbicides, such as glyphosate or glufosinate. In 2014, 154 million hectares of herbicide-resistant crops were planted, and 78.8 million hectares of insect-resistant crops were planted. This included 51.4 million hectares in thirteen countries where crops had both herbicide resistance and insect resistance. Less than one million hectares of genetically modified crops had other traits, such as virus resistance, delayed aging, changed flower color, or altered plant composition. Drought-tolerant maize was planted for the second time in the United States on 275,000 hectares.

Genetically modified crops that resist herbicides are now more widely available than traditionally bred resistant varieties. They covered 83% of the total genetically modified crop area, which is about 8% of the world’s arable land. Approval has been given to grow crops resistant to herbicides such as 2,4-dichlorophenoxyacetic acid, dicamba, glufosinate, glyphosate, sulfonylurea, oxynil, mesotrione, and isoxaflutole. Most herbicide-resistant genetically modified crops were made to tolerate glyphosate, with 93% of soybeans in the United States and most genetically modified maize also being glyphosate-tolerant.

Most genes used to make crops resistant to insects come from the bacterium Bacillus thuringiensis. These genes produce special proteins called cry proteins, which help protect plants from insects. A few crops use genes that produce vegetative insecticidal proteins. Insect-resistant crops protect against beetles and moths. The only gene used for insect protection that does not come from Bacillus thuringiensis is the Cowpea trypsin inhibitor (CpTI). CpTI was first approved for use in cotton in 1999 and is now being tested in rice.

Many genetically modified crops have more than one resistance trait. This could include multiple insect-resistant genes, multiple herbicide-tolerant genes, or a mix of both. Smartstax is a type of genetically modified maize that has eight different genes added, making it resistant to two types of herbicides and protecting against six types of insects.

While most genetically modified crops are made to resist insects or tolerate herbicides, some are developed for other traits. For example, flowers have been engineered to display colors they cannot naturally produce, such as blue in roses. Some crops, like genetically modified papaya, are made to resist viruses. Other changes alter the plant’s composition to improve nutrition, extend shelf life, or make them more useful for industry. Recently, crops that can tolerate drought have been made available for commercial use.

Genetically modified crops by country

The following graph shows the area planted in GM crops in the five countries that grow the most GM crops. The area planted is shown along the y-axis in thousands of hectares, and the year is shown along the x-axis.

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