Herbicide-defying “superweeds” have become an all-too-real problem affecting more than 60 million acres of farmland. A recently published policy brief, “The Rise of Superweeds – and What to Do About It,” from the Union of Concerned Scientists (UCS) explains how we got ourselves into this problem.
When Monsanto introduced a new line of genetically engineered seeds called “Roundup Ready” in the 1990s, they were promoted as a way to make weed control easier. The seeds were genetically altered to be immune to glyphosate, the active ingredient in Monsanto’s patented herbicide, Roundup. Since glyphosate is less toxic than other common herbicides, the Roundup Ready system was hailed as an environmental breakthrough – until it backfired.
As farmers began to use more and more Roundup, genes for glyphosate resistance began to spread in weed populations. The growth of resistance accelerated as farmers increasingly abandoned other weed control measures, relying exclusively on Roundup instead of using a variety of herbicides or crop rotation. All this enabled weeds to flourish, and so the superweed crisis was born.
Instead of learning from its mistakes, the pesticide and seed industry has created a new generation of genetically engineered, herbicide-resistant crops to fight back against superweeds. These products are currently awaiting USDA approval. The fundamental problem with this approach, however, is that weeds that developed resistance to glyphosate are capable of doing the same to new herbicides as well.
There are better, healthier ways for farmers to control weeds. The Union of Concerned Scientists recommends that farmers adopt practices grounded in the science of agroecology, including crop rotation, cover crops and judicious tillage, using manure and compost instead of synthetic fertilizers and taking advantage of the weed-suppressing chemicals that some crops produce naturally. These practices not only control weeds, but also make farmland healthier by increasing soil fertility and water-holding capacity while reducing water pollution and global warming emissions.