This time of year, mature canola seeds can take a long time to turn brown or black. Growers wondering why seed colour change is taking so long may want to check the fields again and look for these other signs of maturity:
All seeds are firm to roll. (See the short video embedded below.) If the latest pods have seeds that are firm to roll, the crop can probably be swathed — even if there is no obvious colour change. Seed can sit for a long time at firm-to-roll stages (which are basically mature) without turning colour, especially if moisture is adequate and temperatures are cool, slowing the dry down process. Mature seed may turn colour fairly quickly after swathing.
No skin peeling. If the skin peels off like “onion skin” when seed is rolled between the thumb and forefinger, then it’s not ready.
If all or most seeds are firm-to-roll, then the odds of those seeds curing properly in the swath are much better, meaning less risk to yield and quality if the crop is swathed to avoid fall frost risk. However, if there is no heavy frost risk is in the forecast, holding off on swathing and letting the plants continue to mature will increase yield and decrease curing time in the swath. As long as the pods are pliable, there is no immediate risk of shattering.