Research indicates that the optimum stage to swath canola for both yield and quality is up to an average of 60% seed colour change (SCC) on the main stem.
To assess SCC, open up pods on the main stem and look at the colour of the seeds. Pod colour is not a good indicator. Some varieties will show pod colour change long before the seeds change, while the opposite is true of other varieties — pods are green while seeds are brown.
For growers faced with uneven maturity within fields, the best approach is to swath when the most mature plants are close to 60% SCC — provided that the least mature plants are showing some seed colour change at the base of the main stem and that seeds in the upper pods (and branches) are dark green and firm. This will minimize yield loss from seed shrinkage and improve the odds that the seed will cure, although it will likely take longer and may require some more moist conditions. Swathing prior to 15 to 20% seed colour change will likely reduce yield potential and could contribute to green seed issues under hot and/or dry conditions.
For more information on harvesting a multi-stage crop, click here to download a 4-page PDF.
Also click here to download the CCC’s “Canola Time of Swathing Guide”