How to determine overall seed-colour change

Listen to a podcast on seed colour change.

All these seeds would be considered "changed."
All these seeds would be considered “changed.”

The optimal swath timing for canola yield and quality is when 60% of seeds on the main stem are showing some colour change. Seed colour change (SCC) is considered any amount of yellow or brown on the seed.

Start in an area of the field that best represents the stand, stage and yield potential of the crop. Pull a plant and isolate the main raceme, which is typically the longest branch with the most pods — representing the greatest percentage of yield. Take pods from the bottom, middle and top of the main raceme.

For 60% SCC, seeds from pods at bottom third of the main raceme will be totally brown to purplish brown, seeds from the middle third will be starting to turn, and seed from the top are green but firm and will roll between your thumb and forefinger without mushing.

Check five plants in this area, then repeat in another couple of places in the field.

Results of Canola Council of Canada 2001-02 research project. Click to enlarge.

Read more in the Swath later for higher yield article.