Sclerotinia stem rot is variable from year-to-year, region to region and even field-to-field.
Plants are most susceptible when the canola crop is flowering, and in high-yielding crops which create dense canopies and when combined with the right environmental factors is the ideal breeding ground for the disease.
Agronomy Specialist Chris Manchur says sclerotinia stem rot is one of the biggest yield robbers for the crop, as a 10 per cent rate of infection can lead to a 5 per cent yield loss.
He says the key is getting ahead of the disease, if you can see symptoms on the plant its too late.
"You need to take a look at some key factors before that actually happens, which usually is around that early flowering period. We're talking about kind of the 10 to 30 per cent flowering. People should be out in their fields and assessing a variety of different factors. That can range from just walking through your field, seeing if your pants are actually wet, because that means that you have that kind of moist humidity, that leaf wetness, and soil moisture to actually produce those spores that will then land onto your petals. "
He notes another thing that you could look at is your plant density, a higher density of canola will increase humidity and help those spores actually germinate.
Another thing to look at is your cropping history, when was the last time a susceptible crop to sclerotinia has been grown? ie soybean, potatoes or sunflowers.
It's important to know what the severity of the sclerotinia was in the field, as the inoculum will return back to the field in later years and cause damage.
"We do have a lot of control methods that we can use to prevent this. Like spraying for fungicides, but we need to know when we want to spray those fungicides. What are the kind of conditions that fungicides are actually warranted, and a lot of that has to do with the environment because sclerotinia loves warm, moist conditions amongst other kinds of factors that could help it proliferate."
Manchur says they are now at the stage where they are looking for farmers across the prairies to work with.
"What we'd like to do is get the number of farms, number of fields across the prairies right now to submit to this tool. So they can reach out to me directly either by phone or by email and we can go and get you signed up for it to get access to the website. You can submit your fields for that step one part, and then we'll return back to those fields later during 30 to 60% seed color change. We'll then go and assess sclerotinia severity and confirm if our recommendations were correct."
Source : Pembinavalley online