Verticillium wilt is a well known global disease that impacts many different crops. Verticillium stripe, however, is a lesser-known disease and one impacting canola, specifically.
They may have similar names, however, they are not nearly the same disease, and it’s important to know that when discussing the disease, says Clint Jurke of the Canola Council of Canada, in this Canola School.
The pathogen causing verticillium stripe plugs up vascular tissue of the stems, says Jurke, and as a result, we see a striping effect.
“We have found that in fact this pathogen is ubiquitous — it’s from the east coast of the country to the west coast. But unfortunately for Manitoba, it seems to be a little heavier as the soil infestation levels are much higher there than they are here in Alberta,” he explains.
One of the trickier aspects of the disease compared to other soil borne diseases is the fact that it doesn’t just stay in the root. With verticillium stripe being in the stem, it produces hardened fungal bodies at the end of the season known as micro-sclerotia. Not to be confused with a different disease canola producers are very familiar with — sclerotinia.
“We often think of sclerotinia, they prove sclerotia which are fairly big chunks of mycelium. The [verticillium stripe sclerotia] are really tiny — not quite microscopic , but they are smaller than pepper,” he explains. “They are produced in the stem, and then when we harvest this crop, unfortunately those stems go through a combine operation, and those microsclerotia get dispersed quite widely. So that’s the real challenge with this particular disease.”
Check out the full conversation, below: