Proponents and critics of genetic engineering in agriculture usually agree on one thing: The technology is powerful, whether for good or ill. Today, the Union of Concerned Scientists broke ranks and asserted that genetic engineering is simply ineffective, at least in increasing crop yields.
UCS's Doug Gurian-Sherman searched the scientific literature for side-by-side comparisons of conventional and genetically engineered lines of corn and soybeans. He found that in almost all cases, genetically engineered crops did not produce larger harvests. The one exception was insect-resistant Bt corn, which produced higher yields only when neighboring plots of conventional corn suffered infestations of a worm called the European corn borer. Crop yields have increased significantly over the past decade, he says, but almost all of that increase was due to traditional plant breeding or other agricultural practices.
These results won't surprise most farmers. They plant crops that have been genetically modified to tolerate doses of the herbicide glyphosate (widely known as Roundup) mainly because that trait makes it easier and sometimes cheaper to control weeds, not because it increases yields. The UCS study is instead aimed at the general public, in an effort to counter claims by the biotechnology industry that genetic engineering offers the best solution to global food shortages.