We are finding quite a few canola plants with healthy developed pods that appear to be sun-bleached red. However, the seeds are completely red, not just the tops or “exposed” areas of the pod to the direct sun.
When opening up the pods, the seeds have stopped developing, and are “pepper,” so to speak, and are yellow and dark brown. The plants seem to be well developed, with no visible diseases affecting them, root to tip. Any ideas?
This sounds like a case of “sunscald” in the canola. This has been seen in several fields since mid-July in Manitoba. It is most likely to occur when canola is ripening during periods of prolonged heat and strong sunlight. The red or purple colour is a stress response caused by high levels of anthocyanin pigment and a lack of chlorophyll in the naturally maturing tissue. It is not a recorded cause of yield loss. Some varieties may be more susceptible than others and high levels in a field do not necessarily mean it is ripe and should be swathed.
The small yellow/brown seeds that look like pepper are probably attributed to the heat during ripening. Hot daytime temperatures and low rainfall during ripening cause the seeds to mature and dry down very quickly. Like the sunscald, there remains lots of seed pigment colour which tends to get locked in due to the environmental stress. Average individual seed weights on canola that ripened in hot/dry conditions also tends to be lower compared to canola that ripened under more moderate temperatures and more rain.
The CropChatter Team