Just like any other crop, timing of when you start harvesting your canola can have a big impact on yield and quality, so here are a few things to keep in mind as you watch your crops progress this fall.
The first decision to make is whether you will be straight cutting or swathing a crop. This is largely influenced by hybrid — if you’ve seeded canola with pod shatter tolerance, such as a BrettYoung Pod DefendR hybrid, you may choose to leave these fields out to straight cut. The second decision to make is whether a pre-harvest aid is required to help with the harvestability of your crop and to even out dry down.
Swath Timing #
Some other things to consider before taking the combine straight to the field are whether or not the plants are well knit together, crop uniformity, crop standability, pod integrity, and frost risk. Field conditions throughout the year can affect all these things, and a field you planned to straight cut in the spring might now be better to swath to avoid large yield losses from unfavourable conditions.
For crops that are facing the risk of frost this fall, it’s important to remember that swathed canola only reduces yield losses from a frost if it has had time to drop below 20% moisture. Disease pressure throughout the year can also have big impacts on your harvest decisions — they may weaken the integrity of the pods, and sclerotinia can run rampant in a swath under the right conditions, causing even more damage.
If you are heading out to swath your canola, you will want to do so at 60% seed colour change (SCC). Determining proper SCC before swathing helps to reduce yield losses and green seed counts. Achieving at least 60% SCC prior to swathing is an underutilized practice in Western Canada. Waiting to swath until after 60% SCC can save growers upwards of 10 bu/ac compared to swathing at that 30 to 40% SCC timing.
Determining SCC #
SCC is determined by opening pods on the main stem of the canola plant. Starting at the bottom and working your way up, open the pods to see if there is any colour change on the seeds (even a small spot on one seed counts). Once you get to the pods that no longer have any colour change, evaluate how much of the plant does have some change in it from 0% (none of the pods having colour change) to 100% (all of the pods having colour change). 60% SCC means that 60% of the way up the main stem, pods should have some SCC to them. Seeds at the top of the stem at this point should be firm, being able to be rolled in your fingers without being squished.
You will want to scout more than just one area, and not just the roadside to determine SCC for a field, come back every couple of days to keep an eye on the progression of the field. If the bulk of the pods (i.e. your yield) are on the side branches and not on the mainstem, alter your assessments to look at those branches more closely.
Pre-Harvest Aids #
With dry, warm days during harvest, your crop and its weeds have time to dry naturally. But if the forecast doesn’t look cooperative, you’re trying to beat frost, or if you’re on a time crunch, a pre-harvest spray may be necessary to help prepare your canola for straight combining. The purpose of using a pre-harvest application is for weed control and crop desiccation.
There are three main options for pre-harvest aids in canola:
- Desiccation (diquat): fast dry down
- Pre-harvest glyphosate: perennial weed control
- Heat® LQ (saflufenacil): dry down and annual weed control
For timing of pre-harvest aids, it is best to talk to the manufacturer and always follow the label rates as all options are to be applied at different crop maturities. Tall canola crops with thicker green stalks benefit from a pre-harvest application to help dry down the stalk and allow for a smoother straight combining experience. No pre-harvest aids will help to quicken plant physiological maturity.
Harvest Timing #
Even if you’ve chosen to straight cut your canola and are leaving it to mature standing, deciding when to harvest is the same timing no matter which method you’ve chosen to go with. You’re looking for no more than 10% moisture — when the pods are dry and you can hear the seeds rattling around inside of them.
Overall, whichever method you choose to take in your canola crop this year, scouting is key. Knowing your field conditions helps to make an informed decision on whether or not to swath and the correct timing for harvest. The end goal is to minimize losses from pod shatter and pod drop through being overly ripe, and to reduce green seed numbers by making sure the crop has been given enough time to ripen.
