Agriculture is facing a new threat in the form of weeds that have developed a resistance to the herbicide Roundup and its generic form, glyphosate. So far, the resistant weeds have not shown up in South Dakota, but are in neighboring Minnesota. One of the weeds that has quickly adapted to become resistant is pigweed, a common plant that is well known in the richer soils of South Dakota. Pigweed (right) can grow three inches a day to six feet tall and is so tough that it can damage farm equipment. Horseweed and giant ragweed are among the ten weeds which have developed a resistance to glyphosate.
The resistant strains of weeds have a gloomy portent for agriculture. Ninety percent of the soybeans grown in the U.S. are genetically modified (GM) to be resistant to Roundup, a herbicide that is applied to soil and kills all plants except the crops genetically modified to be resistant to it. Seventy percent of the corn and cotton grown in the U.S. are also such GM crops.
Roundup herbicide has had advantages for agriculture in South Dakota. It lessens the amount of work it takes to grow crops, it has changed the methods of farming to lessen erosion and toxicity problems. As an herbicide, it is much less dangerous and toxic than other chemicals and degrades without leaving much residual chemicals in the soil.
The use of Roundup in South Dakota has all but eliminated the phenomena of pink air every spring. When fall and spring plowing was the method of preparing the soil for planting, the Dakota winds would whip the dry earth into the air and give the sky a pinkish cast. That airborne dust contained many chemical residues, so that some people with sensitivities to the chemicals had to wear masks during the windy, dusty season, or even leave the state until the air cleared up. Minimum tillage agriculture which leaves crop residues to cover the earth and utilizes glyphosate to prevent the growth of weeds is largely responsible for cleaning up the air and reducing soil erosion to a remarkable degree.
In its coverage of the resistant weed problem, The New York Times reports that farmers are having to return to old, labor-intensive farming practices and are trying various combinations of weed control to see what might reduce the weed problem.
Monsanto Chemical owns the patent on Roundup and a number of the genetically modified crop seeds engineered to be resistant to it. Monsanto has aggressively enforced its patent rights with teams of field investigators who search out farmers who have GM seeds that they haven’t bought from Monsanto. In some cases, farmers have been brought into court for using seeds that they grew themselves but became crossed with GM strains from neighboring fields.
On top of the uncontrollable weeds that have developed a resistance to Roundup much like that in the GM crops, an early test of GM soybeans by members of the Russian academy of science have indicated that hamsters fed GM soybeans have developed fertility and developmental problems, and possibly heightened development of allergies. A major concern with U.S. agricultural exports has been that some countries block GM-grown crops. While the Russian tests are too preliminary from which to draw conclusions, they may harden some nations against accepting GM crops and cause others to block them in the future.
A documentary film, “Food, Inc.,” has also called into question Monsanto’s patented hold on agriculture and the approval of GM crops for human and animal consumption. The testing procedures for determining whether GM crops can have any effect on the humans and animals who eat them are inadequate and have not been developed to the point where scientists feel confident in their results.
SDSU President David L. Chicoine sits on the board of Monsanto, a paid position. He was Dean of the College of Agriculture at the University of Illinois, which works closely with Monsanto in its research and development and marketing programs. While the Roundup resistant weeds have not invaded South Dakota yet, the concerns about Monsanto and its products and practices have.
In a year when farmers in the northeastern part of the state can’t get into their fields because of flooded roads and saturated soils, the herbicide-resistant weeds and the questions about GM crops cast deeper shadows on agriculture, which is struggling for viability in these parts.
Update: Larry Kurtz has called attention to this article on glyphosate in Scientific American.