The popularity of genetically modified crops with US farmers is increasing but Michael Duffy, associate director of the Leopold Center for Sustainable Agriculture at Iowa State University, says this has nothing to do with economic factors.

Duffy recently studied information on more than 300 Iowa farmers, which was gathered by the US Department of Agriculture. His findings, published in the Leopold Center newsletter, showed that farmers using GM crops were not gaining any economic advantage over farmers using conventional seeds.

Any economic advantages bought by the GM varieties requiring less herbicide were generally negated by smaller yields and the higher costs of seeds. In other cases, where farmers used the GM corn seeds designed to repel European corn borers, the advantages of higher yields were counterbalanced by higher fertilizer costs and higher seed costs.

Duffy explained that US farmers were still choosing to use the GM crop varieties because they are viewed as insurance against any insect infestation. Furthermore, he concluded: “For herbicide-tolerant soybeans, farmers answer by saying they can cover more acres more quickly and they don’t have to worry about weed management as they did in the past.”