I’ve spent quite a bit of time in harvested canola fields this fall. It might be because canola started coming off in late August or that there were so many acres this year that almost every second field is canola stubble, but whatever the reason, I’ve noticed most fields have a few things in common.
It’s understandable that once a field is harvested very little goes on there. Some soil test, some spray perennials and others may also add some cultivating, harrowing or a fertilizer application. Nearly all of this fall field work is done from a cab, and that means you’re missing out on three key things you can and should be scouting for in your canola stubble.
1. Blackleg vs. Sclerotinia
At harvest, a dead plant is a dead plant. But once the hustle and bustle of harvest is over, go back into your canola field, get down low and take a look at the standing stubble, especially where you noticed dead and brittle plants. See that greying at the base of the stem? Look closer and it’s likely blackleg, not sclerotinia. In the fields I walked this fall it took me less than 10 seconds to find at least one blackleg infested stalk — it took even less time for some fields. Why does it matter? I discuss that in this post. Check it out. For those in Alberta, now is not the ideal time to scout for clubroot, however, keep that in mind when trying to determine what killed your canola.
2. Plant stand counts
Canola seed is darn expensive, I know. It’s also very small and so incredibly vulnerable to poor seeding operations and conditions, early flea beetle damage and frost. All of these can add up to significant plant losses. Post-harvest is an excellent time to take stock — what was your actual plants per square foot? What contributed to that number? What could you change next year to improve that number? The ideal, by the way, is seven to 14 plants per square foot. How did your fields measure up?
3. Volunteer canola
The number of fall germinating canola seed (or seed left on the surface) tells you two things. First, perhaps your combine settings needed a tweak. It’s possible to lose several bushels out the back of the combine. Playing with and evaluating combine settings every harvest is worth the time. The second thing this observation may tell you is what magnitude of volunteers you’ll have to deal with next year. Rotating herbicide tolerant canola systems is a good resistance management tool and can mean cleaner fields. If you’re sticking with the same system, a pre-seed tank-mix is key.
The Canola Council has also done up its own list on six post-harvest tasks for each field. I’ll second the need for weed scouting and control. As noted in an earlier RealAgriculture post by Shane Thomas, fall is the best time to tackle perennials and winter annuals.