Truth: Conventional breeding outstrips GM in delivering climate-ready crops

Myth at a glance

Tolerance to extreme weather conditions and resistance to the pests and diseases that often accompany them are complex traits that cannot be inserted into plants through genetic engineering. Claimed GM successes in this respect are actually conventionally bred plants with added GM traits for herbicide tolerance or to produce Bt insecticidal toxins.

Conventional breeding is far ahead of genetic engineering in delivering climate-ready crop varieties that often have additional useful qualities such as pest- and disease-resistance.

Only part of the solution to climate change lies in plant genetics. The other part lies in climate-resilient agriculture based on proven agroecological techniques, such as building the soil to conserve water and planting a diversity of crops.

Climate change is often used as a reason to claim that we need GM crops.1 But the evidence suggests that the solutions to climate change do not lie in GM. This is because tolerance to extreme weather conditions such as drought and flooding – and resistance to the pests and diseases that often accompany them – are complex traits. That means they are the product of many genes working together in ways we do not yet fully understand. Such complex genetic traits cannot be delivered through GM.

Where a GM crop is claimed to possess complex traits, they have generally been achieved through conventional breeding, not GM. After the complex trait is developed through conventional breeding, simple GM traits such as pest resistance or herbicide tolerance are added to the conventionally bred crop to represent the “inventive step” necessary to enable the GMO developer company to patent it.

While the resulting crop is often claimed as a GM success, this is untrue. It is a success of conventional breeding with added GM traits. The GM traits do not contribute to the agronomic performance of the crop but make the crop the property of a GMO company and (in the case of herbicide tolerance) keep farmers dependent on chemical inputs sold by the same company.

Hollow promises vs. existing solutions

GMO developer companies have promised for years that GM would deliver climate-ready crops that would help humankind survive climate change. But these promises have proved hollow.

Some thought the breakthrough had finally come in December 2011, when the US Department of Agriculture (USDA) deregulated Monsanto’s drought-tolerant maize variety, DroughtGard MON87460.2 It was hailed as the first commercialized GM maize variety designed to tolerate drought.3 But the USDA, in its assessment of the crop, noted that many non-GM maize varieties on the market are at least as effective as Monsanto’s engineered maize variety in managing water use.4

According to calculations based on Monsanto’s own data by Dr Doug Gurian-Sherman of the Union of Concerned Scientists, DroughtGard GM maize has at best delivered around a 1% US nationwide increase in yield under moderate drought conditions only,5 whilst conventional breeding coupled with improved agronomy and agroecological practices have provided a 1% year-on-year yield benefit.56

This is to be expected, given that GM crops are developed by adding GM traits to the best conventionally bred varieties.

Meanwhile, conventional breeding, sometimes helped by marker assisted selection, has outstripped GM in producing numerous climate-ready crops.

Examples include:

  • Maize varieties that yield well in drought conditions,7 including some developed for farmers in Africa89101112
  • Cassava that gives high yields in drought conditions and resists disease13
  • Climate-adapted, high-yield sorghum varieties developed for farmers in Mali14
  • Beans resistant to heat, drought, and disease1516
  • Pearl millet, sorghum, chickpea, pigeon pea and groundnut varieties that tolerate drought and high temperatures17
  • Rice varieties bred to tolerate drought, flood, disease, and saline (salty) soils18
  • Drought-resistant rice that yields up to 30% higher than other local varieties in Uganda19
  • Flood-tolerant rice varieties developed for Asia20,21
  • Over 2,000 indigenous rice varieties variously adapted to environmental fluctuations and resistant to pests and diseases, registered by Navdanya, an NGO based in New Delhi, India22
  • Tomato varieties developed by Nepali farmers that tolerate extreme heat and resist disease.23

These are just a few examples among many. GMWatch keeps a database of non-GM breeding successes on its website.24

Genetics not the whole solution

Only a part of the solution to climate change lies in plant genetics. Insofar as genetics is the solution, humanity will continue to rely on the same source that GMO developer companies mine for their germplasm – the hundreds of thousands of locally adapted seed varieties developed and conserved over centuries by farmers worldwide. These varieties are our living germplasm bank.

That part of the solution that lies beyond plant genetics is found in proven effective agroecological farm management techniques, such as building organic matter into the soil to conserve water, water conservation and management, planting a diversity of crops, rotating crops, and choosing the right plant for the conditions.

Conclusion

Tolerance to extreme weather conditions and resistance to the pests and diseases that often accompany them are complex genetic traits with multiple gene functions at their basis. These complex traits cannot be inserted into plants through genetic engineering, which is limited to manipulating one or a few genes. Claimed GM successes in this respect are actually conventional breeding successes with added GM traits for herbicide tolerance or to produce Bt insecticidal toxins. These GM traits do not contribute to the agronomic performance of the crop under adverse weather conditions.

Conventional breeding is far ahead of genetic engineering in delivering climate-ready crop varieties that often have additional useful qualities such as pest- and disease-resistance.

Only part of the solution to climate change lies in plant genetics. The other part lies in climate-resilient agriculture based on proven agroecological techniques, such as building the soil to conserve water and planting a diversity of crops.

References

  1. Gray L. GM foods “could feed growing population during climate change.” The Telegraph (UK). http://tgr.ph/nnywRL. Published January 22, 2009.
  2. Abbott C. U.S. approves Monsanto drought-tolerant GM corn. Reuters. http://reut.rs/KyB8pX. Published December 22, 2011.
  3. Marshall A. Drought-tolerant varieties begin global march. Nat Biotechnol. 2014;32(308). doi:10.1038/nbt.2875.
  4. Voosen P. USDA looks to approve Monsanto’s drought-tolerant corn. New York Times. http://nyti.ms/mQtCnq. Published May 11, 2011.
  5. Gurian-Sherman D. High and dry: Why genetic engineering is not solving agriculture’s drought problem in a thirsty world. Cambridge, MA: Union of Concerned Scientists; 2012. Available at: http://www.ucsusa.org/assets/documents/food_and_agriculture/high-and-dry-report.pdf.
  6. Yu T, Babcock BA. Are US corn and soybeans becoming more drought tolerant? Am J Agric Econ. 2010;92:1310-1323.
  7. Gillam C. DuPont says new corn seed yields better in droughts. Reuters. http://reut.rs/Li0c5B. Published January 5, 2011.
  8. Cocks T. Drought tolerant maize to hugely benefit Africa: Study. Reuters Africa. http://bit.ly/bPXW0p. Published August 26, 2010.
  9. La Rovere R, Kostandini G, Tahirou A, et al. Potential impact of investments in drought tolerant maize in Africa. Addis Ababa, Ethiopia: CIMMYT; 2010. Available at: http://bit.ly/1mLExYQ.
  10. Atser G. Ghanaian farmers get quality protein, drought-tolerant, and Striga-resistant maize varieties to boost production. Modern Ghana. http://bit.ly/LZolNL. Published April 2, 2010.
  11. Khisa I. Drought tolerant maize varieties ready. The East African. http://www.www.theeastafrican.co.ke/news/Drought-tolerant-maize-varieties-ready/-/2558/2134334/-/yk6a9p/-/index.html. Published January 4, 2014.
  12. Atser G. Nigeria releases two extra-early maturing white maize hybrids. modernghana.com. http://www.modernghana.com/news/482841/1/nigeria-releases-two-extra-early-maturing-white-ma.html. Published August 17, 2013.
  13. International Institute of Tropical Agriculture (IITA). Farmers get better yields from new drought-tolerant cassava.http://bit.ly/L3s946. Published November 3, 2008.
  14. Diarra ST. Resistant seed helps Mali farmers battling climate change. AlertNet. http://bit.ly/Li0AkE. Published January 11, 2011.
  15. Yao S. ARS releases heat-tolerant beans. USDA Agricultural Research Service. http://www.ars.usda.gov/is/pr/2010/100630.htm. Published June 30, 2010.
  16. USDA Agricultural Research Service. Help for the common bean: Genetic solutions for legume problems. Agric Res USDA. 2010; May-June. Available at: http://www.ars.usda.gov/is/ar/archive/may10/bean0510.htm.
  17. International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). ICRISAT develops climate change ready varieties of pearl millet, sorghum, chickpea, pigeonpea and groundnut. SeedQuest. http://bit.ly/KqvVoV. Published June 5, 2009.
  18. Berthelsen J. A new rice revolution on the way? AsiaSentinel. http://bit.ly/Lzthdi. Published January 17, 2011.
  19. Food and Agriculture Organization (FAO). Uganda: After decades of war, a new rice variety helps farmers resume their lives. http://www.fao.org/news/story/en/item/35606/icode/. Published October 2, 2009.
  20. International Rice Research Institute (IRRI). Indian farmers adopt flood-tolerant rice at unprecedented rates. ScienceDaily. http://www.sciencedaily.com/releases/2010/09/100915151015.htm. Published September 15, 2010.
  21. IRIN News. Philippines: Could flood-resistant rice be the way forward? http://www.irinnews.org/Report.aspx?ReportId=82760. Published February 5, 2009.
  22. Commodity Online. GM and India’s rice fields. http://www.rediff.com/money/2007/mar/02comod4.htm. Published March 2, 2007.
  23. Giri A. Nepali farm develops disease, heat resistant tomato. OneIndiaNews. http://news.oneindia.in/2010/12/05/nepalifarm-develops-disease-resistant-tomatoes.html. Published December 5, 2010.
  24. GMWatch. Non-GM successes. 2014. Available at: http://www.gmwatch.org/index.php/articles/non-gm-successes.