Verticillium has been impacting canola crops in Manitoba for over a decade, but it is now spreading across the Canadian Prairies.
According to Jeanette Gaultier of BASF, while verticillium was first detected in Manitoba around ten years ago, it has since been found in every canola growing region of Canada, except the Atlantic provinces.
Verticillium is very specific to brassica species, penetrating the roots early in the season, and growing upwards through the stem. By the end of the season, dark micro sclerotia form on the outer stem, which can then shed back into the soil to infect next year’s crop.
Though difficult to determine precisely how long the disease can persist in the field, research suggests verticillium can remain viable in the soil for many years.
The real kicker is, how do you identify it? Often, it is misidentified for other canola diseases such as blackleg. Because of the nature of the disease impacting the stem, the similarities can be many, taking a trained eye to decipher — which is why Gaultier suggests sending your canola stem into a lab if you have suspicions.
The most standard symptom of the disease is the striping of the stem, with half of it turning green, and the other half brown. Taking a crop section of the stem reveals discolouration across the entire stem. If you wait until later in the season to scout, such as post harvest, the stems will be dry, and the epidermis peels back, creating visible dark micro sclerotia.
How will it impact each field? The answer is a very standard one to agronomy — it depends. The severity will depend on disease pressure, environmental conditions, and of course, whether the pathogen is present. In severe Manitoba fields, some farmers report yield drags, while in other cases, plants may lodge badly while leaving yields mostly unaffected.
Check out the full conversation between Gaultier and RealAgriculture’s Kara Oosterhuis, below: