Editing Genetically modified maize (section)

=== Herbicide-resistant maize ===
Corn varieties resistant to [[glyphosate]] herbicides were first commercialized in 1996 by [[Monsanto]], and are known as "Roundup Ready Corn". They tolerate the use of [[Roundup (herbicide)|Roundup]].<ref>{{cite web|title=Roundup Ready System |url=http://www.monsanto.com/weedmanagement/Pages/roundup-ready-system.aspx |publisher=Monsanto |url-status=dead |archive-url=https://web.archive.org/web/20130402204619/http://www.monsanto.com/weedmanagement/Pages/roundup-ready-system.aspx |archive-date=2 April 2013 }}</ref> [[Bayer CropScience]] developed "Liberty Link Corn" that is resistant to [[glufosinate]].<ref>{{cite web |url=http://www.bayercropscience.us/products/herbicides/liberty/|title=Bayer LibertyLink official website|publisher=Bayer Crop Science|access-date=28 October 2014}}</ref> [[Pioneer Hi-Bred]] has developed and markets corn hybrids with tolerance to [[imidazoline]] herbicides under the trademark "Clearfield" – though in these hybrids, the herbicide-tolerance trait was bred using tissue culture selection and the chemical mutagen ethyl methanesulfonate, not [[genetic engineering]].<ref name="imidcorn" >{{cite journal | vauthors = Tan S, Evans RR, Dahmer ML, Singh BK, Shaner DL | title = Imidazolinone-tolerant crops: history, current status and future | journal = Pest Management Science | volume = 61 | issue = 3 | pages = 246–57 | date = March 2005 | pmid = 15627242 | doi = 10.1002/ps.993 }}</ref> Consequently, the regulatory framework governing the approval of transgenic crops does not apply for Clearfield.<ref name="imidcorn" />

As of 2011, herbicide-resistant GM corn was grown in 14 countries.<ref>{{cite web | vauthors = James C |title=ISAAA Brief 43, Global Status of Commercialized Biotech/GM Crops: 2011|work=ISAAA Briefs|publisher=International Service for the Acquisition of Agri-biotech Applications (ISAAA)|location=Ithaca, New York|year=2011|url=http://www.isaaa.org/resources/publications/briefs/43/executivesummary/default.asp|access-date=27 July 2012}}</ref> By 2012, 26 varieties of herbicide-resistant GM maize were authorised for import into the [[European Union]],<ref>{{cite web | author = Staff | url = http://ec.europa.eu/food/dyna/gm_register/index_en.cfm | title = EU register of genetically modified food and feed | work = European Commission, Health and Consumers, EU register of authorised GMOs | access-date = 26 August 2012 }}</ref> but such imports remain controversial.<ref>{{cite web | vauthors = Hogan M | date = 5 April 2012 | url = https://www.reuters.com/article/us-germany-gmo-basf-idUSBRE8340Y120120405 | title = BASF to undertake GMO potato trials in Europe | work = Reuters Edition US | access-date = 26 August 2012 }}</ref> Cultivation of herbicide-resistant corn in the EU provides substantial farm-level benefits.<ref name="Wesseler-2007">{{cite journal | vauthors = Wesseler J, Scatasta S, Nillesen E | title = The maximum incremental social tolerable irreversible costs (MISTICs) and other benefits and costs of introducing transgenic maize in the EU-15. | journal = Pedobiologia | date = August 2007 | volume = 51 | issue = 3 | pages = 261–9 | doi = 10.1016/j.pedobi.2007.04.004 | url = https://mpra.ub.uni-muenchen.de/33229/1/MPRA_paper_33229.pdf }}</ref>