Deep seeding in canola

Seeding too deep will delay germination, thus reducing seed yield and oil content.

Weak seedlings with pale cotyledons

What to look for


  • Pale and weaker plants that are more frequent in softer soil areas or along seeding rows.
  • Early sown crops are less affected than those sown in cold wet conditions


  • Seedlings have delayed emergence and are more susceptible to waterlogging and root disease.
  • Emerged plants have a longer hypocotyl, and smaller cotyledons with pale margins.
  • Very deep sown seedlings may fail to emerge.

What else could it be

Condition Similarities Differences
Diagnosing poor quality seed in canola Lack of vigour Do a germination test or check seed depth to determine cause

Management strategies

  • Canola seed sown to a depth of 12-25 mm into a firm, moist seedbed germinates rapidly with a high emergence percentage.
  • On sandy soils or where the topsoil dries quickly, planting can be slightly deeper, around 30 mm.
  • Seed larger than 2 mm diameter (5 mg) will also help when sowing deeper.
  • Late sown canola in June-July should be sown at 1-2 cm for rapid emergence.
  • Be wary of varying soil types within paddocks. Seeding equipment may sink further in sandy soils, changing the seeding depth.

How can it be monitored?

  • Test the seed depth with a higher seed rate to make finding the seed easier, but don't forget to change back to normal seed rate.

Where to go for expert help

Mark Seymour
+61 (0)8 9083 1143
Page last updated: Friday, 17 April 2015 - 11:52am