Herbicide tolerant crops
Herbicide tolerant (HT) crops are the biggest selling GM crops. These crops have been made to be tolerant to either Monsanto's weedkiller RoundUp (glyphosate) or Bayer's weedkiller Liberty (glufosinate ammonium). These are broad spectrum herbicides which kill all green plants except those protected as a result of the genetic modification. Recently, the first crops tolerant to Dow's 2,4-D, a more toxic weedkiller, have been approved for commercial growing in South Africa.
Monsanto's RoundUp Ready soybeans are the leading product. Other herbicide-tolerant crops include maize, sugar beet, and oil seed rape (canola).
Herbicide-tolerant GM crops have been attractive to the biotechnology companies as they have been able to
- sell both the herbicide and the GM seeds as a package
- place the same gene sequences into each of these major crop types
- gain intellectual property rights over the modified seeds and thus charge an annual technology fee.
Herbicide-tolerant GM crops have been attractive to a number of large-scale farmers in North and South America because in the early years after adoption they simplified the spraying regimes i.e. farmers only had to spray them once with with one type of herbicide, saving labour costs. However, repeated blanket applications of the same herbicide have led to herbicide-resistant superweeds evolving. These superweeds are now reducing crop yields and require repeated applications of multiple herbicides and sometimes even pulling up by hand. There are concerns about the impacts on of pesticide residues on human health, on wildlife, and on farmers' livelihoods.
The existence of superweeds is now being used by the companies involved to justify developing new GM crops tolerant to other herbicides, which may be even more damaging. "The weed resistance problems currently infesting U.S. farms are rapidly getting worse, and growers need new technology now to maintain productivity. Within the past year, the number of weed-resistant farm acres in the U.S. has increased by about 25 percent." Dow AgroSciences USA press release, April 2012.
In the USA, agro-chemical and GM seed companies now recommend that farmers use tank mixes of multiple herbides to try to tackle the superweed problem.
In 2012, South Africa approved Dow's GM maize (corn) engineered to be tolerant to the weedkiller 2,4-D (one of the ingredients in Agent Orange). The controversial GM maize, plus the same trait engineered into soybeans, are awaiting approval in the USA. The crops are intended to be planted in response to the spread of superweeds tolerant to Monsanto's weedkiller RoundUp (glyphosate), which have arisen due to use of the company's RoundUp Ready GM crops. In the short term, this will allow the superweeds to be killer by 2,4-D, but in the longer term resistance to this weedkiller will also develop. A significant increase in the use of 2,4-D is expected, leaving toxic residues in the food chain and damaging neighbouring crops due to drift during spraying.
In late 2012, Dow announced plans to introduce GM soybeans which are tolerant to three different weedkillers.
In South America, local people and some scientists have raised concerns about the health effects of being sprayed with the herbicides used on GM soya. Much of this soya is exported to Europe for use in animal feed.
In the UK, the Farm Scale Evaluations ran from 1999-2004. Herbicide-tolerant GM sugar beet, maize and oilseed rape (winter and spring) were grown along side conventional crops to monitor their ecological effects. The studies found that the changes in herbicide use associated with growing these GM crops had negative effects on wildlife.
- GeneWatch reports
- Consultation responses
- GeneWatch UK response to USDA consultation on Dow's 2,4-D tolerant corn and soybeans (12th February 2014) 12th February 2014
GM Freeze and GeneWatch UK: Joint response to EPA consultation on tolerances for residues of glyphosate in or on multiple commodities (1st July 2013)
Repsonse to plans to increase allowed levels of glyphosate (brandname RoundUp) allowed on oilseed crops (soya, flax and oil seed rape) in the food chain in the USA from 20ppm to 40ppm. Higher levels of weedkillers are needed for GM crops because of increased spraying due to superweeds. Some of these crops may be imported to Europe for use in animal feed.
- Press articles
- Mail Tribune: Scientists find multiple problems with GMOs (13th April 2014)
- La Junta: Farmers warn of threats to economics posed by genetically engineered crops (17th March 2014)
- Reuters: Group seeks court order on USDA over genetically modified alfalfa (13th March 2014)
- Reuters: As Dow seeks growth, new Enlist crop/chemicals seen as key (10th March 2014)
- BBC: Fears for Mexico's butterfly population (19th February 2014)
- Huffington Post: Meet the New Monsanto: Dow Chemical... and Their New 'Agent Orange' Crops (18th February 2014)
- Dallas News: Climate change, weed killers treacherous for Texas monarchs (12th February 2014)
- The World Post: Last Call For Monarchs (7th February 2014)
- Mail Tribune: The weed resistance crisis in American GMO agriculture (2nd February 2014)
- MongaBay.com: Migrating monarch butterflies hit shockingly low numbers (31st January 2014)
- RT: Monsanto blamed for disappearance of monarch butterflies (31st January 2014)
- News 24: Monarch butterflies drop, migration waning (30th January 2014)
- Mother Earth News: Take This Chance to Speak Up on Genetically Modified Crops and 2,4-D Herbicide (29th January 2014)
- The Guardian: Monarch butterfly numbers drop to lowest level since records started (29th January 2014)
- AP: Monarch butterflies drop, migration may disappear (29th January 2014)
- Off the Grid News: Farmers Abandoning GMO Seeds And The Reason Will Surprise You (4th January 2014)
AP: Government might deregulate corn, soybean seeds (3rd January 2014)
Reports plans to allow commercial plantings of GM crops resistant to the weedkiller 2,4-D in the USA.
- Huffington Post: USDA May Deregulate Corn And Soybean Seeds Able To Withstand Weed Killer Used In Agent Orange (3rd January 2014)
- The Ecologist: 'Harmful' weedkiller in your bread and cereal bars (31st December 2013)
- Daily Mail: How Frankenstein 'superweeds' have swamped 60 MILLION acres of US farmland - and can't be killed (11th December 2013)
- Modern Farmer: The post-GMO economy (6th December 2013)
- AgProfessional: BASF survey shows majority face glyphosate-resistant weeds (4th December 2013)
- New York Times: The Year the Monarch Didn't Appear (22nd November 2013)
- GreenMedInfo: How Roundup Weedkiller Can Promote Cancer, New Study Reveals (11th November 2013)
- Agri.eu: Commission considers backing new GM crop despite gaps in its safety testing (31st October 2013)
- Mother Jones: Argentina Is Using More Pesticide Than Ever Before. And Now It Has Cancer Clusters. (23rd October 2013)
- Seattle Times: Track record mixed for GE crops (19th October 2013)
- Globo: Transgenicos: Ministerio Publico pede a CTNBio que suspenda liberacoes [In Portuguese] (2nd October 2013)
- The Ecologist: Are you eating 'pesticide plants'? (12th September 2013)
- Scottish Farmer: GM - the next generation (10th September 2013)
- Pagina 12: Una ONG ambientalista objeta una nueva semilla [In Spanish] (5th September 2013)
- Wired.co.uk: Study: weeds get unintended 'fitness' boost from genetic modification (19th August 2013)
- Nature: Genetically modified crops pass benefits to weeds (16th August 2013)
- RT: Another win for Monsanto: US raises allowable levels of company's pesticide in crops (23rd July 2013)
- St. Louis Post Dispatch: Some farmers want more scrutiny of new Monsanto crops (18th July 2013)
- The Gazette: Herbicide-resistant weeds gaining ground in Iowa (4th July 2013)
- Forbes: GMO Crops Mean More Herbicide, Not Less (2nd July 2013)
- IPS: U.S. Weighing Increase in Herbicide Levels in Food Supply (2nd July 2013)
- China Digital Times: Soybean Imports Revive Fears About GM Food (24th June 2013)
AgriPulse: USDA extends comment period for GE crops (10th June 2013)
Reports that the U.S. Department of Agriculture (USDA) has extended the public comment periods for certain herbicide resistant crops developed by Dow AgroSciences and Monsanto to 17th July 2013. Online public meetings are also proposed to consider the crops genetically engineered to be resistant to the herbicides known as 2,4-D and dicamba.
- ABC News: Glyphosate resistance on the rise in Australia (15th May 2013)
- The Guardian: Tracking the causes of monarch butterfly decline (18th April 2013)
- Mother Jones: Monsanto Claims to Ditch Herbicide While Selling More of It (10th April 2013)
- Huffington Post: My War Against GM Crops (24th March 2013)
- Farmers Weekly: US farmers may stop planting GMs after poor global yields (6th February 2013)
- UPI: Resistant weeds said threat to U.S. crops (4th February 2013)
- Farm Industry News: Glyphosate-resistant weed problem extends to more species, more farms (29th January 2013)
- Reuters: UPDATE 1-Dow's controversial new GMO corn delayed amid protests (18th January 2013)
- Agriculture.com: New GM corn delayed until 2014 (18th January 2013)
- The Western Producer: Scientist raises concerns about GM crops and glyphosate (21st December 2012)
- Mother Jones: Meet the Weeds That Monsanto Can't Beat (20th December 2012)
- GRTV: Farmer to Farmer: The Truth About GM Crops (17th December 2012)
- New York Times: Pesticides: Now More Than Ever (11th December 2012)
- The Guardian: European Commission could open GM pandora's box (7th November 2012)
- Guardian: How GMOs unleashed a pesticide gusher (3rd October 2012)
- Independent Science News: Seralini and Science: an Open Letter (2nd October 2012)
- Reuters: Pesticide use ramping up as GMO crop technology backfires: study (1st October 2012)
- Daily Mail: Russia suspends import and use of American GM corn after study revealed cancer risk (29th September 2012)
- The Guardian: Study linking GM maize to cancer must be taken seriously by regulators (28th September 2012)
- BBC News: Agent Orange chemical in GM war on resistant weeds (19th September 2012)
- The Grocer: Monsanto Roundup weedkiller and GM maize implicated in 'shocking' new cancer study (19th September 2012)
- The Telegraph: GM crop enquiry launched by French government (19th September 2012)
- Deutsche Welle: Soy production endangers Argentina (3rd September 2012)
- IOL News: Controversial GM mielies get green light (24th July 2012)
- The Grower: Glyphosate-resistant weeds also may be disease resistant (18th July 2012)
- Mother Jones: USDA Prepares to Green-Light Gnarliest GMO Soy Yet (18th July 2012)
- Science News: Glyphosate-Resistant 'Superweeds' May Be Less Susceptible to Diseases (17th July 2012)
Reuters: US House biotech proposal would bypass courts - critic (5th June 2012)
Reports plans to re-start plantings of GM sugar beet in the US, while court cases are ongoing.
- Nature: War on weeds loses ground (22nd May 2012)
- Daily News Tanzania: Superweeds caused by GMO are super problems (20th May 2012)
- Superweeds: A Long-Predicted Problem for GM Crops Has Arrived (15th May 2012)
- Ottawa Citizen: Reaping what we sow (12th May 2012)
- Reuters: Super weeds no easy fix for US agriculture-experts (10th May 2012)
- San Francisco Chronicle: Genetically modified crops' results raise concern (30th April 2012)
- New York Times: A Battle Over an Engineered Crop (25th April 2012)
- Farmers Weekly: US growers petition government over GM crops (25th April 2012)
- Reuters: Analysis - Dow's new corn - "time bomb" or farmers' dream?
- Delaware Online: As Roundup's effect fades, farming costs rise (17th April 2012)
- Summit Voice: Popular weedkiller causes deformities in amphibians (3rd April 2012)
- StarTribune: Study ties GMO corn, soybeans to butterfly losses (16th March 2012)
Mother Jones: How NPR Got It Wrong on Monsanto's Superweeds (14th March 2012)
Includes some history on how Monsanto's RoundUp Ready trait was discovered.
- Penn State Live: Integrated weed management best response to herbicide resistance (9th February 2012)
- Bloomberg: Monsanto Says Weedkiller-Resistant Kochia Found in Western Canadian Fields (12th January 2012)
- Farmers Weekly: Resistance to Roundup is increasing (7th November 2011)
- Forbes India Magazine: Bt Brinjal and India's Wake-up Call (20th October 2011)
- ArabNews.com: Super weeds pose growing threat to US crops (19th September 2011)
- Wallaces Farmer (USA): Glyphosate-Resistant Weeds Are Huge Challenge (9th August 2011)
- St Louis Today: Resistant weeds leave farmers desperate (17th July 2011)
New York Times: In Midwest, Flutters May Be Far Fewer (11th July 2011)
Reports that the growing use of herbicide-tolerant genetically modified crops is threatening the monarch butterfly by destroying the milkweed on which it lays its eggs.
The Guardian: Global food crisis: the speculators playing with our daily bread (2nd June 2011)
Dan Basse, president of AgResource (Chicago) tells the Guardian that the promise that biotech seeds would deliver big increases in yields has turned out to be illusory. He also fears that "superweeds are coming on so fast with GM that US farmers are going to have to go back to more traditional cultivation methods [as opposed to the practice with GM seeds of not tilling the soil and simply spraying to control pests] - but they don't have the capacity to do that."
- The Telegraph: GM soy: the high cost of the quest for 'green gold' (17th May 2011)
- Wall Street Journal: Superweed Outbreak Triggers Arms Race (4th June 2010)
- Press releases
- GeneWatch UK PR: Supermarkets must stop harm to Monarch Butterfly, end GM animal feed use 30th January 2014
- Testbiotech, GeneWatch UK and the Pesticide Action Network (PAN) PR: Stop risky herbicide 2,4-D (27th January 2014) 27th January 2014
- GeneWatch UK PR: Second generation of GM crops resistant to more toxic weedkillers expose industry's diversionary PR strategy 30th August 2013
- External links
- RALLT, African Centre for Biosafety, Third World Network (2014) Open letter to the UN Re: Impact of GM herbicide-resistant crops on the right to food (April 2014)
- NDRC: Monarch butterfly population hits a new low (29th January 2014)
- WWF: Monarch Population Hits Lowest Point in More Than 20 Years (29th January 2014)
- Center for Food Safety: New report shows record decline in Monarch Butterflies: Monsanto a major culprit (29th January 2014)
- Union of Concerned Scientists: Fait Accompli - USDA Decision on Herbicide-Resistant Crops Betrays Farmers and the Public (8th January 2014)
- Center for Food Safety: "Agent Orange" Crops Would Trigger Massive Increase in Use of Toxic Pesticide 2,4-D (3rd January 2014)
- Union of Concerned Scientists: The Rise of Superweeds - and What to Do About It (December 2013)
- 2,4-D and dicamba-resistant crops and their implications for susceptible non-target crops (7th November 2013)
- Michigan State University: 2,4-D and dicamba-resistant crops and their implications for susceptible non-target crops (7th November 2013)
- Testbiotech: Spraying with glyphosate leaves high levels of residue in soybeans (22nd October 2013)
- Center for Food Safety: New Genetically Engineered (GE) Crop Will Sharply Increase Use of Toxic Pesticide, a "Probable Human Carcinogen" (29th August 2013)
Food and Water Watch: Genetically Engineered Foods
Includes a cartoon explaining the rise of superweeds and impacts on Monarch butterflies.
Gaban BL (2013) Comparison of Roundup Ready and Conventional Soybean (Glycine Max L.) Weed Control Systems for Optimizing Yield and Economic Profitability (May 2013)
Finds no significant difference in yield between RoundUpready (glyphosate-resistant) soybeans and conventional soybeans.
- Save our Crops Coalition: SOCC Opposes New Uses of Dicamba and Residue Tolerances for Monsanto's Dicamba Tolerant Crops (17th January 2013)
- CRIIGEN: Long-term toxicity study of GM herbicide-tolerant maize (September 2012)
- Genok: Report: Soybean Production in the Southern Cone of the Americas: Update on Land and Pesticide Use (July 2012)
- Rabo AgFocus: Nature Finds a Way: The Rising Cost of Herbicide Resistant Weeds in the U.S. (June 2012)
- PAN: Dow and Monsanto in deadly race on the pesticide treadmill (11th January 2012)
- Friends of the Earth Europe: Herbicide resistant crops
- GeneWatch briefings