Editorial

Imagine, if you will, a seed that allows farmers to use less pesticides, thus reducing their exposure to toxic chemicals. It also makes possible low- or no-till cropping systems, thus protecting the environment.

At the same time, it increases yields and saves money.

That pretty well describes the conclusions a panel of scientists from the National Research Council drew about genetically engineered crops.

They focused on crops such as corn, soybeans and cotton that have been genetically engineered to be glyphosate tolerant or produce Bacillus thuringiensis toxins that are lethal to the larvae of some insects.

These crops are not a silver bullet for farmers, the scientists warned. Such crops must be properly managed to avoid the development of herbicide-resistant weeds or toxin-resistant insects. Just as the use of the same types of pesticides year after year will tend to develop resistance, so do cropping systems that rely on genetically engineered traits, the scientists concluded.

Overall, though, the report was an affirmation of the experience farmers have had with genetically engineered crops since they were introduced in 1996.

The research council's study focused primarily on the effect that technology has had on farmers. In a word, that effect has been dramatic.

"The committee finds that genetic-engineering technology has produced substantial net environmental and economic benefits to U.S. farmers compared with non-GE crops in conventional agriculture," the panel concluded.

But the summary adds a caveat. "However, the benefits have not been universal; some may decline over time, and the potential benefits and risks associated with the future development of technology are likely to become numerous as it is applied to a greater variety of crops."

The study's major conclusions were:

* As farmers adopted herbicide-resistant crops, they used glyphosate instead of more toxic herbicides. "However, the predominant reliance on glyphosate is now reducing the effectiveness of this weed-management tool," they wrote.

* "The adoption of herbicide-resistant crops complements conservation tillage practices, which in turn reduces the adverse effects of tillage on soil and water quality," they wrote.

* "Insecticide use has decreased with the adoption of insect-resistant crops," they wrote, noting that insect resistance to the technology has been low.

* For the three major genetically engineered crops -- corn, soybeans and cotton -- cross-breeding into wild or weedy relatives hasn't been a problem. However, they said that accidental cross-breeding with the non-genetically altered crops "remains a serious concern for farmers whose market access depends on adhering to strict non-GE presence" in their crops, they said. "Resolving this issue will require the establishment of thresholds of the presence of GE material in non-GE crops, including organic crops, that do not impose excessive costs on growers and the marketing system."

* Farmers who have adopted GE crops have experienced lower costs of production and higher yields, including in some areas where insect populations were hard to treat without such crops.

* Increased worker safety and greater flexibility of farm management have resulted. New varieties with multiple traits also reduce production risk.

Overall, the panel gave genetically engineered crops a thumps-up, with the positives outweighing the negatives.

Judging from the conclusions of this report, here's another example of how technology has helped farmers and the environment in measurable ways.