Genetic Engineering So Far Fails to Deliver Climate Solutions

A new report published by the Union of Concerned Scientists (UCS) reviews the failings of  biotechnology to develop  drought-tolerant crop varieties for our increasingly parched landscapes.

High and Dry: Why Genetic Engineering Is Not Solving Agriculture’s Drought Problem in a Thirsty World,” provides an analysis of the prospects for genetic engineering new crop varieties that can thrive under drought conditions and reduce demand on dwindling water resources. Given the record-breaking 2011 drought in Texas and the expectation that climate change will bring more frequent and severe droughts, we will need solutions to growing food under such extremes.  The question is whether we can genetically engineer our way out of climate change.  And the answer seems to be no — at least so far.

Using USDA data, UCS researchers find that the only approved drought-tolerant GE seed variety developed by Monsanto shows underwhelming performance for its not-so-cheap seed. The so-called “DroughtGard” corn increased yields by only one percent and did not improve water use efficiency. The UCS website has a succinct summary of the findings in the report and the organization’s recommendations, provided below.

Genetic engineering is costly, has limited applications and plenty of unintended consequences. We cannot afford to abandon publicly-funded classical plant breeding.  Senator Tester (D-MO) has introduced a “Seeds and Breeds” amendment to the Farm Bill that would enhance research funding for classical plant and animal breeding. Classical breeding research projects aim to give farmers access to improved crop cultivars and livestock breeds that are better adapted to diverse farming systems and regional variations. Though much more modestly funding that the millions that go into developed GMO crops, classical plant breeding has a long and respectable track record of success — more than can be said of DroughtGard.

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High and Dry Summary of Findings & Recommendations

1.  A Small Bang for Big Bucks

Though the mid-2000’s saw a surge in field trials for crop varieties with engineered drought tolerance traits, as of 2012 only one such variety—Monsanto’s DroughtGard, containing the engineered genecspB—had been approved by the USDA.

The results so far paint a less than spectacular picture of DroughtGard’s effectiveness: USDA analysis of data supplied by Monsanto show that DroughtGard produces only modest results, and only under moderate drought conditions at that. The report estimates that cspB corn would increase the overall productivity of the U.S. corn crop by only about one percent. And DroughtGard does not improve water use efficiency.

The evidence suggests that alternatives to GE—classical breeding, improved farming practices, or crops naturally more drought-tolerant than corn, such as sorghum and millet—can produce better results, often at lower cost. If we neglect these alternatives because of exaggerated expectations about the benefits of GE, we risk leaving farmers and the public high and dry when it comes to ensuring that we will have enough food and clean freshwater to meet everyone’s needs.

2.  Why Drought Tolerance Is So Challenging

There are several reasons why a GE magic bullet for drought tolerance may prove elusive. Drought tolerance is a complex trait that can involve many different genes, corresponding to different ways the plant can respond to drought; genetic engineering can manipulate only a few genes at a time. And in the real world, droughts vary widely in severity and duration, affecting the crop at different stages of its growth, so any engineered gene will be more successful under some drought conditions than others.

Genes that improve drought tolerance may have other effects on crop growth, some of which may be undesirable—a phenomenon known as pleiotropy. This has been commonly observed with many otherwise promising drought tolerance genes, and is likely a reflection of the interconnectedness of drought response with many other aspects of plant growth.

Molecular biologists try to reduce the negative effects of pleiotropy by ensuring that the engineered genes only become active under drought conditions, but if droughts are prolonged, the harmful effects may be hard to avoid.

3.  Market Uncertainties

If Monsanto’s cspB corn can meet these challenges, it will still face market hurdles. For starters, DroughtGard will have to compete in the marketplace with drought-tolerant varieties produced through less expensive breeding methods.

Another challenge for cspB corn is that farmers buy their seeds well before they plant. Because drought is not reliably predictable, many farmers may not want to pay the higher price of engineered drought tolerance just in case drought occurs. This may largely restrict planting of cspB corn mainly to areas where moderate drought is frequent, such as the western regions of the U.S. Corn Belt.

Other factors important for marketing seed include the overall quality of the corn varieties that the cspB is placed in and how these compare to competitors varieties.

4.  Recommendations

Given the status of R&D on GE drought tolerance and water use efficiency and challenging questions about its prospects, UCS recommends that:

  • Congress and the USDA should substantially increase support for public crop-breeding programs to improve drought tolerance.
  • Congress and the USDA should use conservation programs funded under the federal Farm Bill to expand the use of available methods for improving drought tolerance and WUE.
  • The USDA and public universities should increase research devoted to finding better ways to store and conserve soil water, groundwater, and surface water, and better farming methods to withstand drought.
  • In particular, organic and similar methods that improve soil fertility simultaneously improve the capacity of soil to store water for crop use during drought, while mulches can reduce soil temperature and reduce evaporation. These methods should be encouraged through incentives.
  • Public and private research institutions should devote more funding and effort to improve crops that are important in drought-prone regions in the Southern Hemisphere.
  • Researchers at the USDA and public universities should carefully monitor the efficacy and possible undesirable effects of cspB corn. Such monitoring is important because this variety is the first GE commercial drought-tolerant crop, and the resulting information would enhance our understanding of GE drought tolerance.
  • The USDA and public universities should expand their research on using plant breeding to improve water use efficiency—a vital concern that has not attracted major efforts from the biotechnology industry.

 

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