Deep seeding in canola

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

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.

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

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.

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.