Herbicide resistance testing
Why carry out herbicide resistance testing?
- Have you noticed a gradual decline in weed control over several years?
- Or do you have one weed type that seems harder to control than others?
- Have you seen healthy weeds beside dead weeds of the same species?
Any of these issues may indicate a herbicide resistance problem. Undiagnosed herbicide resistance could mean you are spending more each year on herbicides that will not work on your weeds.
Herbicide failure in the field could occur to a range of issues (timing, conditions, etc.). Therefore, do not assume you have herbicide resistance. You may just be missing the opportunity to use a very effective herbicide.
What factors lead to herbicide resistance in weeds?
Herbicide resistance risk could be increased by:
- Repetitive application of herbicides with the same mode of action
- Multiple herbicide applications during the same growing season
- A lack of non-chemical management
- Using herbicides with long residual periods
- A lack of crop rotation
- Reduced or less effective dose rates of herbicide are applied
Female inspecting crops whilst holding tablet computer
Which weed species could have herbicide resistance?
Poppy
Chickweed
Groundsel
Blackgrass
Italian ryegrass
Wild oats
Mayweed