Frost hit many parts of the Prairies last night and earlier this week. The big questions for growers are: How soon after a frost should I swath? Or if I was lucky enough to miss this frost, do I go ahead and swath canola now to avoid the risk of the next one? The answer depends on a few factors, including the maturity of the crop and the temperature and duration of the frost.
Growers who had a frost need to get out and assess the damage in each field. Canola is often unscathed by a light frost of 0 to -2 C and can be left standing to mature further to improve yield and/or grade. But canola with severe wilting or whitening of pods should be swathed quickly to preserve seed volume, since the damage to grade is likely already done.
For growers looking at swathing ahead of the next frost, keep in mind that swathing when the crop is very immature with lots of translucent seed may mean dealing with the same issues (lost yield and/or green seed) whether the frost comes or not. However, for growers with lots of acres still standing, swathing crops with some seed colour change and signs of physiological maturity on most of the green seed should be considered to minimize the overall impact if a killing frost arrives.