Questions of the Week

What funding is available through Canola 4R Advantage?

The CCC is now accepting applications for year two of Canola 4R Advantage, which provides funding to help pay for BMPs focused on nitrogen management, including soil testing, field zone mapping and enhanced efficiency fertilizers. As a reminder, growers have access to several enhancements in year two of the program, including the funding limit increase to $20,000 per eligible BMP per farm (up from $6,000 in year one). Find complete program details here. Are you planning to apply for Canola 4R Advantage? Whether your answer is yes or no, let the CCC know by completing our short, four-question survey today.

What’s wrong with my canola?

Once swathing begins, it becomes much easier to walk fields and see clear evidence of disease infection that may have been overlooked in the growing season. Scout carefully for the big four: pull plants and cut stems (cutting once below the soil line and again at the soil surface) for blackleg and verticillium, assess roots for clubroot, assess the exterior of the stem for verticillium and sclerotinia (note: long flowering caused significant sclerotinia infection, even in fields that were sprayed). Refer to this simple canola disease scouting guide, the ‘Is it verticillium stripe or blackleg?’ guide, and this video. Spending 30 minutes assessing and recording disease (or asking your agronomist to!) near harvest can have more impact on future years’ success than any other 30-minute field management investment. While scouting disease, take time to count plants too using the  canola counts calculator. Plant counts at harvest are as or more important than spring counts.

What is turning canola grey/black?

According to AAFC plant pathologist, Dr. Kelly Turkington:

“Sooty moulds are a group of saprophytic fungi that grow on normally mature or prematurely ripened plants, turning them from a nice harvest golden brown colour to a dusty dark grey/black colour due to superficial growth of the sooty mould fungi. The main species that hitchhike onto and infect dead or damaged tissue are Alternaria spp. (not the pathogenic ones!) and Cladosporium spp. They typically occur if there are wet conditions post maturity that delay the timely harvesting of crops, or on prematurely ripened plant tissues killed by abiotic stresses (e.g. hail, flooding, drought, high temps) or biotic factors (root rots, insect damage, etc.) in moist conditions. Normally sooty moulds are not an issue in terms of yield loss, but instead may lead to excessive weathering and discolouration of plants and harvested crop. 

Alternaria blackspot (pathogenic species of Alternaria) normally results in leaf lesions and then eventually blackish flecks/lesions on the pod tissues. It is very evident before plants start to turn colour and mature. The unaffected parts of the pods are still green, and you don’t see the general dusty grey/black that is typical of sooty mould. Alternaria blackspot typically affects the rarely grown Polish canola (B. rapa) more than Argentine canola (B. napus). Sulphur deficiency can contribute to a substantial increase in Alternaria blackspot.” 

Some fungicide labels indicate Alternaria control in canola but are most likely mentioned as a side benefit from late or second pass sclerotinia fungicide applications. Like sclerotinia, by the time a grower identifies Alternaria infection that is severe enough to warrant fungicide, the spray decision is too late. With no or limited impact on yield, a targeted preventative fungicide application for Alternaria is generally economically impractical.  Always read and follow label directions, including preharvest intervals. There are no effective management tools for sooty moulds.

How to tackle kochia?

There are two main factors to consider regarding managing kochia at harvest.

1. Avoid green seed in the bin: Kochia, which can be widespread and stays green into the fall, contributes more to canola heating in the bin than any other weed species. Glyphosate resistant kochia must be swathed or treated with a layered herbicide to be successfully combined. (Control green seed to reduce storage concerns)
2. Minimize weed seed spread: A single kochia plant can produce more than 15,000 seeds. Mowing a kochia plant patch increases the weed seedbank in that specific area but limits the seeds’ spread into other parts of the field. Plan now to intensively manage next year any patches that are mowed this year. Swathing and burning is another option to manage kochia in fall, but ensure swathed weeds don’t spread seeds by tumbling. Research shows kochia shed seed at 1585 growing degree days. A combine seed destroyer can effectively manage a large percentage of kochia seeds if canola is harvested as soon as it is mature. Pre-Harvest herbicides may not reduce the weed seed bank. (How to contain herbicide resistant kochia) (Resistant weed management)

How to assess maturity in uneven fields?

Uneven emergence and challenging growing conditions mean plant staging is patchy and/or variable in many fields. Maximizing profitability depends on accurately assessing maturity and determining where the majority of yield will be. Refer to the Canola Council of Canada’s Canola Swathing Guide for tips on how to assess an uneven field. (What to do with uneven fields) (Harvest management – timing, quality and yield)