Weeds are a reality of the world we live in and an especially prominent reality for farmers. Weeds can have a number of negative impacts on crop production and our environment: they compete with other plants for precious resources; decrease wildlife habitats; decrease water and soil quality; and increase wear and tear costs of farming equipment.
Herbicides offer effective control against many weed species and are used on a high percentage of crops in the U.S. With the advent of crop biotechnology in the 1990s, farmers had access to seeds that possessed weed-resistance traits, thereby limiting the amount of herbicide needed to protect their crops. Today, nearly 90 percent of corn acres in the U.S. are planted with genetically modified seed. However, farmers still rely on herbicides in order for additional protection that biotechnology sometimes cannot provide.
The Weed Science Society of America (WSSA) points out that the introduction of herbicide-resistant crops does not necessarily coincide with the evolution of herbicide-resistant weeds. “A plant does not evolve resistance because herbicides cause a genetic change in the plant that makes it resistant,” WSSA reported. Rather, the process takes place over time as a few plants with natural resistance to an herbicide begin to reproduce until they overtake the number of non-resistant plants in a field.
Taking these issues into consideration, what do farmers do to tackle weeds? Similar to integrated pest management (IPM), integrated weed management (IWM) measures can help prevent the spread of weed resistance. Some factors involved in IWM that can reduce the proliferation of weeds include crop rotation, good soil fertility, cover crops and planting date. Selecting different types of herbicides rather than sticking to one compound can also help control herbicide-resistance.
There is no single solution that can guarantee the complete eradication of weeds, but crop protection products can significantly reduce weed infestations. The advantages of using herbicides to control weeds prevent farmers from returning to labor-intensive hand-weeding and unsustainable tillage techniques.