As a professional vegetation manager, it is important to understand how weeds develop resistance, and what strategies you can implement to delay resistance.
What is herbicide resistance?
Resistance is the naturally occurring inheritable ability of some weed biotypes within a given weed population to survive a herbicide treatment that would, under normal use conditions, effectively control that weed population.
What are some of the current situations leading to the increased development of herbicide resistance globally?
- Frequent use of herbicides with a similar site of action in a growing season in the same field
- Crop rotations that rely on similar site of action herbicides
- Limited non-herbicide weed control options in-crop
Today, Canadian industrial vegetation managers have approximately 8 groups of herbicides available to control target weeds on our industrial sites.
To date, the development of resistant weeds in industrial settings has been limited as a result of the best management practices you have already been implementing:
- Using full rates
- Calibrating your equipment to ensure proper rates are being applied
- Using high water volumes to get good coverage
- Spot spraying vs full broadcast year after year
- Most roadsides and utility rights-of-way only receive one herbicide application every three to five years
- Excellent monitoring; returning to the sites to ensure weed populations are controlled and managing any that haven’t been controlled; and lastly
Other best management practices we recommend implementing to decrease the risk of resistance developing:
- Rotate herbicides groups -- not product brand names
- Select herbicides with multiple modes of action – each with activity on the target weed
- Use herbicide mixtures containing different herbicide groups with activity on your target species. This has been proven to be more effective than just rotating herbicides.
- If possible, adjust timing of application. Try to avoid applying at the same time year after year, as this can potentially lead to selection of certain weed species.
Leaders in industrial vegetation management for more than 50 years, Corteva Agriscience provides you with the products, tools, and education to help delay resistance.
Our trusted herbicide solutions provide elite control of a broad spectrum of broadleaf weeds, brush and invasive plants.
It’s important to remember the long-term sustainability of herbicides remaining an effective tool to manage vegetation is in your hands.