It’s September 23. Do I cut that green canola?

September 10, 2014 - Issue 23

September 23, 2015 - Issue 27

swathing canola

As we progress further into September, growers get more anxious to swath. Swathing at 60% seed colour change is still preferred, but by this date some growers don’t want to wait any longer. Here are some scenarios that may help with the decision to go or wait:

What’s the forecast?

—Warm temperatures. If all seeds are green but firm, a couple days of heat before swathing could move that seed along quickly. If the local forecast is for warm temperatures in the next week, waiting to swath will be beneficial.

—Frost. Canola swathed in anticipation of frost needs to dry down to less than 20% seed moisture to avoid significant damage from a frost event. If frost is in the forecast but the days are too cool and wet to allow sufficient drying, swathing before the frost won’t help. It may be better to leave the crop standing, and then if a frost occurs, decide when to swath based on the amount of damage. The amount of damage will depend on seed stage, moisture, the amount and duration of freezing temperatures. Click here for more information.

Time Management. How much canola is left to swath? If there is more canola standing than can be reasonably swathed within a couple days after a frost, then swathing a few fields early might be good risk management. Ensure seeds throughout the plant are firm when rolled between thumb and forefinger, and if possible, wait for at least some seed colour change. Mushy, watery seeds will likely be lost.

Combine Timing. Swathing early does not mean combining early. Canola swathed green takes a lot longer to cure than canola swathed at 50% to 60% seed colour change. Whether growers swath a green crop now or wait a week, combining will likely occur around the same time. And by cutting early, the crop may not meet its yield and quality potential.

Curing time. When the long-term forecast is wet and cool, early swathing when canola seeds are firm but green often does not lead to high green counts —provided growers are patient and allow for the additional curing that must take place in the swath. By contrast a period of hot, dry weather before the green is cleared can lock in high green counts.

Further reading:

Don’t wait for green to clear

Canola Watch