Resistance Testing

If you see unusual weed escapes resport them!

• A weed species that should have been controlled but is healthy while other susceptible species have been controlled.
• A weed control failure even when the correct herbicide rate was used and it was applied at the appropriate weed stage and under favourable environmental conditions.

Then stop a potential problem from getting worse. If you see weeds that you suspect are resistant, report them by calling:

By taking advantage of this toll-free number, suspicious weed species will be tested for resistance by the University of Guelph. Any information obtained from this service will allow weed researchers to develop control options for resistant weed populations.