The Great Debate On GMO Crops

Iowa Farm Scene

Believing in safety of genetically modified crops depends on trust and science.

Published on: November 4, 2013

"The U.S. is quickly becoming like a feudal system of farming," says Rosmann. "Farms are growing larger and larger, and there is less crop diversity." The trend to larger farms hurts rural communities, he points out.

Rosmann says farmers in the U.S. are using more chemicals than ever, which he says is harmful to livestock and wildlife. He also believes GMO technology has increased the number of herbicide resistant weeds. "The claim by the biotech industry that pesticide use has decreased with biotechnology isn't true," he said. "Because of weed resistance to glyphosate, herbicide use in the U.S. has increased by 500 million pounds."

ISU weed scientist says increase in weeds that resist herbicides isn't the fault of GMO crops

Mike Owen, the ISU weed scientist, countered Rosmann's statement. "The increase in weeds resistant to herbicide is not attributable to GMO crops," says Owen. "It's how the crops and weeds are managed, as management decisions are made. Weed resistance is a management issue, not the fault of genetic modification."

Owen says a lack of crop diversity, not GMOs, in many ways is the real issue. Also, a lack of diversity in weed control tactics. "Farmers have switched to using a system that is lacking in diversity—and predictably the system is now pushing back as we are seeing more problems with herbicide-resistant weeds."

However, Owen says the herbicide resistant crop technology does help allow more acres to be farmed with no-till. "That is creating less soil erosion and improved water quality because it is supporting conservation tillage agriculture," he noted.

Yields and grain quality on the farm have improved, thanks to biotechnology

Rosmann said herbicide-resistant weeds cost Tennessee farmers $120 million last year in extra herbicide use and in lost yields due to the rise in weed control problems. He believes weed resistance to herbicides will be far more costly to Iowa farmers in future years.