12 Factors Influencing Canola Seed Survival

Not every canola seed turns into a seedling. In fact, the Canola Council of Canada reports only 50 to 60 percent of seeds - both open-pollinated and hybrid - generally produce viable seedlings.

However, the survival rates can vary from 25 to 75 percent, depending on a range of factors. Knowing and accounting for these factors may help growers make better estimates of optimal planting rates.

Here are some factors to consider:

  1. Seed size. In some cases, larger seeds offer more vigor. This can help the plant cope with early stresses. Hybrid seed vigor usually is better than open-pollinated seed vigor. Less robust seed should have warmer soils, shallow planting depth and slightly higher plant populations.
  2. Seed chlorophyll. Higher chlorophyll content can reduce vigor and increase seed mortality. Levels should be below 35mg/kg.
  3. Hybrids. Typically, hybrids have 10 to 20 percent greater vigor than open-pollinated varieties.
  4. Seedbed temperature. Cold soils (lower than 40 degrees Fahrenheit) at planting and in the following two weeks can increase seed mortality by up to 20 percent. Canola prefers soils of at least 50 degrees for germination.
  5. Frost. Early frost can thin stands. The earlier you plant, the higher population you may need to overcome potential losses to frost.
  6. Seed depth. Optimum planting depth is a half to a full inch below the press wheel furrow. Deeper planting requires more time for emergence, reduces plant populations and decreases growth. Maturity may be delayed. In addition, seedling disease risks rise.
  7. Seeding speed. The faster you plant, the less likely you'll plant uniformly. Seed survival may suffer. If you have to plant quickly to cover a large number of acres, realize you may lose more seeds to early-season stresses.
  8. Fertilizer in the seed row. Too much fertilizer, especially nitrogen, can increase seed mortality.
  9. Seeding equipment and seedbed quality. Too much compaction, too little seed-soil contact or too much residue all can hurt seed performance.
  10. Tight rotations and disease. If you go fewer than two years between canola crops in a field, you could increase the opportunity for seedling diseases to impact stands.
  11. Weeds. Heavy weed pressure can increase seed mortality. The seed must compete for nutrients and sunlight. Early-season weed control helps. Denser canola stands also will be more competitive with weeds.
  12. Insects. Heavy pressure from flea beetles can thin a stand even with high rates of insecticide seed treatments. If flea beetle populations are high in fall, spring pressure is likely to be high. Higher seeding rates can spread insect pressure over more plants. Other pests to monitor are cutworms and wireworms.