Believe it or not, spring is just around the corner, and before you know it you’ll get the itch to get your equipment rolling and put seed in the ground.
Peas (mostly) go first, when it’s still a little cold and damp. In fact, lots of peas are seeded when there’s still a bit of snow on the north side of the hills.
If that’s how you roll, germination and vigour tests are an absolute must. Even when you’re seeding in almost perfect conditions, these tests still hold the keys to targeting your ideal plant population.
Germination tests measure how many seeds will grow in ideal conditions. Some seeds take in water but do not germinate; dormant seeds are viable but fail to germinate under test conditions; hard seeds have a seed coat that is too hard to allow water to pass through; and dead seeds will not produce any part of a seedling.
Vigour tests measure how well the seed will perform under stressful conditions.
Knowing germination alone leaves you entirely unprepared for less-than-ideal conditions. For example, you can have 99% germ and 80% vigour, and as soon as you put a stressor on the seed, it may not live up to its promise. (In reality, a good result is at least 85%. Anything less and I’d worry about the seed quality – enough to recommend sourcing new seed.)
Make sure to test twice: first after harvest and cleaning; then again six weeks before seeding because a lot can happen as temperatures and moisture levels fluctuate during the months in storage. Test each seed lot (every 20 tonnes) separately.
Remember that seed represents your potential. It’s where your yield comes from, so it’s really important to start with healthy, high-potential seed. You’ll also be able to calculate a more accurate seeding rate if you understand both germination and vigour. If you have good germination but poor vigour, you may have to up your rate to offset it.
This also underlines the importance of a seed treatment, as it provides another layer of protection that gives your seed the extra vigour it will need under stressful conditions.
Consult your Cargill agronomist if you have questions about seed treatments and seeding rates. We’d like to help you achieve that ideal plant population – and maybe we can convince you to wait until all the snow melts...
Typical vigour tests
- Cold Germination: Tests the seed’s ability to withstand cold stress (5-7° Celsius) that’s normal for early seeding conditions.
- Accelerated Aging: Predicts storage and field planting potential. Seed is placed under high humidity and high temperature for a period of time. The amount of germination determines vigour (90% germ is considered high vigour).
- Controlled Deterioration: Tests storage performance. Seed is brought to 20% moisture and held there for an extended amount of time to determine rate of deterioration.
- Electrical Conductivity: Seed is soaked in deionized water, allowing sugars, starches and amino acids to leach from the seed. The water is tested for electrical conductivity. *ProTip: High EC should be used with caution.
- Seedling Growth Rate: Seed germinates under optimal conditions and growth rate, size, and root length is measured to determine vigour. Different varieties have different characteristics so the lab technicians need to know their varieties.
Written with files from Allison Hebert.