Calculate germination percentage from seed tests. Adjust seeding rates based on actual germination to achieve target plant populations.
Seed test: 100 seeds, 85 germinated. Target seeding rate 100 kg/ha at 95% standard germination.
Increase seeding rate by 12% to achieve target plant population. If germination falls below 70%, consider buying new seed.
Germination % = (Seeds germinated ÷ Total seeds tested) × 100. For a standard 100-seed test: 95 germinated = 95% germination. Certified seed requires minimum 85% for most crops.
Certified seed: Wheat/barley 85%, Canola 80%. On-farm saved seed: aim for 85%+. Below 70% discard or increase seeding rate significantly. Old seed loses 5-15% germination per year.
Adjusted seeding rate = Target rate × (Standard germination ÷ Actual germination). Example: Target 100 kg/ha at 95% germination. Actual 85% = 100 × (95 ÷ 85) = 112 kg/ha.
Count 100 seeds. Place on damp paper towel inside a plastic bag. Keep warm (20-25°C). Count germinated seeds after 7 days (cereals) or 10 days (canola). Repeat for accuracy.