Herbicide Resistance: Are you at risk?
Herbicide resistance is a growing problem that can have serious impact on the success
of your growing season – now and in the years to come. The good news is that there
are more options than ever before for managing herbicide resistance.
Like LibertyLink® Soybeans. By rotating to the
LibertyLink Soybean system, you get a high-yielding crop along with the powerful,
non-selective weed control provided by first-in-class Liberty® herbicide.
You can out-manoeuvre herbicide resistance
The fundamental point in reducing the incidence of herbicide resistance is rotating
production practices – breaking the cycles that enable herbicide resistance to develop.
Rotate crops: Since certain weeds are more prevalent in a particular
crop, the same population of weeds will be repeatedly exposed to the same herbicide,
presenting greater opportunity for resistance to develop. Crop rotation can introduce
a different season of growth, vary the weed population, and involve different classes
Rotate herbicides: Repeated use of one herbicide maintains selection
pressure on a particular weed population, and increases the likelihood that resistant
plants will survive and reproduce.
Rotate modes of action: It can be tempting to continue to use a
herbicide that has been highly effective. Over several years, though, repeated use
of the same mode of action gives resistant weeds the opportunity to set seed, multiply
and spread throughout a field.
Other handy management tips
Weed seed deposition: High seed production by plants that have
developed resistance leads to a higher proportion of resistant plants in the weed
population. Controlling weeds before they produce seed will help reduce growth of
Tillage: No-till or reduced-till farming practices can generate
weed control challenges, and advancements in herbicide technology provide crucial
support to the success of reduced/no-till farming. Careful planning of herbicide
use will help optimize weed control.
Weeds thrive on routine! Adding LibertyLink Soybeans to your rotation will help
you to out-manage herbicide resistance
Differential diagnosis: Is it really herbicide resistance, or…?
Accurately identifying resistance is the first step toward putting renewed weed management strategies into action.
It shouldn't be immediately assumed that resistance is the cause. Other potential reasons should first be considered, including:
- herbicide application: inappropriate dose or timing, or faulty sprayer
- weed factors: very high coverage, size of weeds, or germination following spraying
- soil conditions: moisture, seedbed quality, adsorption
- environmental conditions: rainfall, temperature.
Field observation can give some important clues to possible resistance. Consider these factors:
- Past experience: If the weed species has previously been well controlled by the same herbicide, but control has become less effective over a period of years, resistance could be the issue.
- Herbicide history: Repeated use of the same herbicide, or herbicides with the same mode of action, favours selection for resistance.
- Are other weed species controlled? If other susceptible weed species are effectively controlled by the herbicide, resistance is a possibility.
- Is there a mix of living and dead plants? This could be a sign of resistant plants, although variations in stage of weed growth or incorrect herbicide application could also explain this situation.
- Is there resistance in nearby fields or farms involving the same weed species and herbicide? If yes, there is a good chance that you're observing resistance.
Test to be sure
If resistance is suspected, a sample of plants and/or seeds should be collected from the suspected resistant population to be tested for resistance.