Genetically modified organisms (GMOs) were first bred into plants in the early 1990s with the promise that they would increase nutrition, provide resistance to drought, and create faster growth. Another trait that has been bred into GMO crops is resistance to herbicides used to kill weeds, while not effecting the crop.

GMO Crops Bred to Withstand Higher Amounts of Glyphosate

The majority of GMO crops, including corn, soybeans, canola, cotton and alfalfa, have been bred to resist one best-selling herbicide called glyphosate, a broad spectrum herbicide that is designed to kill a variety of weeds. Glyphosate is the primary active ingredient in a popular herbicide sold in stores and now also in the herbicides of a number of other manufacturers.

Weeds Evolve Resistance to Glyphosate

Since the herbicide glyphosate was first used in 1970, weeds have adapted and evolved resistance to it, requiring stronger and stronger amounts of glyphosate to kill them. Considering the increasing number of GMO crops today that are designed to resist glyphosate, the Environmental Protection Agency (EPA) estimates that 180 to 185 million pounds of glyphosate are used in US agriculture each year.

The Effect of Glyphosate on Plants Animals and Humans

Unlike other herbicides, glyphosate does not directly kill the weed or plant with which it comes in contact. Instead, it binds to important minerals such as manganese and calcium needed for growth, making them unavailable to the plant. Because manganese also is essential for plant defense against diseases in the soil, the extensive use of glyphosate has caused an increase in crop diseases.

There is recent research suggesting that the increase in crop diseases caused by glyphosate could be effecting animals fed GMO corn and soybean feed. Veterinarians have also identified genetically modified plants, especially soybeans and corn consumed by cattle, pigs, sheep, goats and poultry, as the cause of reproductive failure in animals (infertility, miscarriage and spontaneous abortions). Scientists have suggested that humans consuming these plants and animals may be likewise effected.