Calculate germination rate, germination energy, and adjust seeding rate based on actual germination test results.
Test seed germination rate and energy, then adjust your seeding rate accordingly. Input total seeds tested, normally germinated, early germination (day 4), field area, theoretical rate, and label germination. Get actual seed rate, total seed required, and extra seed needed. Always test before planting.
You bought "certified 95% germination" alfalfa seed and planted at the standard 15 kg/ha. Emergence was patchy — only 60% ground cover. You sent a sample to the lab and got 72% germination. The seed was 3 years old and had been stored in a hot shed. You needed 20 kg/ha, not 15. The 5 kg/ha shortage cost you 30% yield in the first cutting. A $5 germination test would have saved you $200/ha in lost production.
Germination rate measures seed viability. Test before planting to ensure optimal plant population.
A: 1) Count 100 seeds (or 50 for large seeds). 2) Place between moist paper towels or on wet sand in a tray. 3) Keep at 25-30°C (77-86°F) — top of refrigerator or seedling heat mat. 4) Keep moist but not soaking. 5) Count germinated seeds at day 4 (energy) and day 7-14 (final rate, depends on species). 6) Repeat 3-4 times for reliability. A seed is germinated when the radicle (root) emerges and is at least as long as the seed.
A: Germination rate (final count, day 7-14): percentage of seeds that germinate given optimal conditions. Measures viability. Germination energy (early count, day 3-5): percentage that germinate quickly and uniformly. Measures vigor. Seed can have 90% germination but only 60% energy — it will eventually sprout but unevenly, causing variable plant sizes and reduced yield. Both matter for field performance.
A: Under cool (5-10°C), dry (<8% moisture) storage: corn 2-3 years, wheat 5-10 years, rice 2-3 years, soybean 2-3 years, alfalfa 5-10 years, onion 1-2 years, lettuce 3-5 years, tomato 4-6 years, pepper 2-4 years. Under warm, humid conditions: viability drops by 50% or more in 1-2 years. Always store seed in airtight containers in a cool, dry place. Old seed may still germinate but at reduced rate and vigor — test before planting.