What is a weed? We typically think of a weed as “a plant out of place.” By this definition, that could apply to any plant in an undesirable location. A volunteer corn seedling in a field of soybeans is a weed. A bermudagrass runner in your flowerbed is a weed. Crabgrass and dandelions in your lawn are weeds. It’s really all about perspective- after all, corn would have been cultivated in the season before soybeans, we really like bermudagrass when it grows in the yard, crabgrass is an important and nutritious forage for wildlife (and livestock), and early settlers of the US brought dandelion over to grow for food.
Every year, Americans spend large sums of money managing weeds with chemicals. This has unfortunately (or fortunately, if you’re a weed) led to populations of herbicide resistant weeds all over the country. While this continues to be a marvel of biology and rapid evolution, it has caused many headaches for farmers. Integrated Pest Management (IPM) has become the norm for producers in the United States who 10 years ago were consistently using glyphosate (roundup) at every turn.
IPM incorporates physical, cultural, chemical and biological methods of controlling pests. It uses pesticides as a last resort, and stresses the importance of rotating chemicals with different modes of action (MOA) to help prevent herbicide or insecticide resistance. It uses the biology of the pest to determine when management is most effective. By tailoring our strategy to each unique situation, we can effectively curb pesticide resistance and promote more environmentally friendly methods on the farm and at home.