Canola Watch quiz: Herbicide injury

If canola plants start to look funny after herbicide spray season, it could be that residues were stripped from the sprayer tank and plumbing, or that spray drifted in from another field. The following images show typical symptoms of foliar herbicide mishaps. Can you name the herbicide group that caused the damage?

1. What herbicide group caused this damage?

2. What herbicide group caused this damage?

3. Two groups are at work here. What are they?

4. Sometimes the cause may seem like herbicide damage, but could be nutrient deficiency or weather related or something else entirely. Through a process of elimination, what did CCC agronomists conclude was the cause of this light-coloured tissue?