Will Genetic Engineering Divert Us from Essential Food Production Science?

August 29, 2011 | 6:53 pm
Doug Gurian-Sherman
Former contributor

Climate change, increasing population, greater demand for animal products, and the un-sustainability of current food production: All will challenge our ability to produce enough food in coming decades. Already there is evidence that climate change has reduced crop yields.

Drought-stricken corn. Photo: bionicteaching

But the good news is that we already have many of the tools that we need to respond.

Tom Philpott at Mother Jones highlights a peer-reviewed article showing that small Mexican maize farmers have an important piece of the answer to these challenges.

The article suggests that there is a lot of genetic diversity in corn grown on traditional small Mexican farms that will allow food production there to adapt to climate change. Genetic diversity provides the building blocks of crop adaptability—the inherited differences between plants that is evolution’s way of allowing survival in changing environments.

The value of crop genetic diversity goes way beyond Mexican maize fields. Other scientists have documented  large amounts of untapped genetic diversity in the world’s major crops wherever they have looked, such as in wheat and cassava. Breeders can use this, along with diversity found in wild species related to crops, to adapt our crops to climate change and to increase productivity.

When coupled with ecological farming principles that increase resilience in the face of drought, flood and rising temperatures, breeding can go a long way toward providing enough food sustainably by mid-century. For example, organic and similar practices build soil organic matter–this allows soil to hold more water which can help during drought. And breeding is already having success in developing drought tolerant ricecorn, and other crops, flood tolerant rice, many types of pest resistance, improved nutrient content, and much more.

Engineered Omissions

Given all the evidence, it is perplexing that some scientists still want to put too many of our eggs in the genetic engineering (GE) basket.  Currently, that basket looks pretty empty, with only a few crops resistant to herbicides and a few types of pests.

For example,  Nina Federoff seems unaware of the potential of breeding, and the advances already being achieved through these scientifically sophisticated methods. In an op-ed in the New York Times, “Engineering Food for All” the former Bush-appointed Science Adviser to the Secretary of State lauds the wonders of crop genetic engineering, while tagging breeding as an “older” method that is “less capable”.

In a more blunt assessment during a public forum that I participated in at Dartmouth College several months ago, Federoff declared that crop breeding had run its course, and implied that GE was now our last best hope.  She could not have been more wrong. The only way one can come to such conclusions is by omitting or overlooking loads of important science.

Most of the benefits from GE extolled in the op-ed are modest at best. They only seem impressive if you don’t compare them to the successes and potential of agroecology, agronomy, or breeding—which continue to achieve far more than GE. When looked at side-by-side, GE often pales by comparison to breeding.

Take drought tolerance for example. While a number of drought tolerant crops have been developed in recent years through breeding–with more to come–the first modest GE version is at least a year or two away. In the U.S., where GE crops have to compete with advanced agricultural methods, the yield increases from engineered genes have been much less than from breeding and improved crop management. If not for the latter methods, and had we relied only on GE instead, overall corn yields in the U.S., the biggest global exporter, would probably be about 25 percent less than they are. Yield of soy, our second biggest crop, would be about 16 percent less.

And for poor farmers in developing countries, methods based on sophisticated ecological principles can far outpace the gains from GE, as pointed out by author Anna Lappé at Civil Eats in her response to the op-ed.

Even where a particular advantage is claimed for GE, the op-ed is often misinformed. Engineered insect-resistance reduces harmful mycotoxins that occur in some corn kernels—an unanticipated bonus. But here too, breeding is showing up its engineered counterparts. Federoff claims that insect-resistant corn prevents fungi, and hence mycotoxins, from contaminating corn. She is only half right. It reduces only one type of mycotoxin, called fumonisin. That’s a good thing. But GE insect-resistant corn does nothing to prevent an even more serious cancer-causing mycotoxin called aflatoxin, caused by other types of fungi. By contrast, conventional breeding, in the hands of the U.S. Department of Agriculture, has recently produced corn that so far shows resistance to both fumonisin and aflatoxin.

The attractiveness and need for GE depends in part on how it stacks up against other agricultural methods and technologies. So far, and for the foreseeable future, breeding and ecologically-based farming will be considerably more effective and cost less. Genetic engineering can have a role if properly regulated, but focusing on it myopically threatens to distract us from supporting better technologies.

[Federoff’s assessment of the risks and regulation of GE is also off base—I’ll address that in my next post.]