ToolsSeeding rate
This PropelMapper calculator turns your target stand, seed-tag germination and survival assumption into a seeding rate.
The target stand, seed-unit size and field area are examples. Your field plan and the supplier’s seed information supply those values.
| Measure | Result |
|---|---|
| Seeding rateRounded to the nearest 100 | 39,500 seeds / ac |
| Seeds per foot of row | 2.3 seeds / ft |
| Units per acre | 0.49 units / ac |
| Units for the field | 39.5 units |
You and the grower have chosen a target stand for the field. With the seed tag beside you, you enter germination and a separate assumption for survival after germination. The calculator works back to the seeds needed under those assumptions.
You record the result with the seed lot and the assumptions you used. A visit note can also hold the planter setting, ready to compare with a stand count after emergence.
We can use that uploaded note to prepare your report. You check the numbers and explain the planting plan before sending it. The agronomic target and later interpretation remain yours.
“Planting-plan example: target 32,000 plants per acre, germination 90 percent and survival after germination 90 percent. The calculated rate is about 39,506 seeds per acre. These are the assumptions used for this example.”
A target of 32,000 plants per acre, with 90% germination and 90% survival after germination, gives about 39,506 seeds per acre.
The calculation uses the stated assumptions; the target is the advisor’s decision.
A target of 32,000 plants per acre, with 90% germination and 90% survival after germination, gives about 39,506 seeds per acre.
The calculation uses the stated assumptions; the target is the advisor’s decision.
After your review
Divide the target stand by germination multiplied by expected survival among the seeds that germinate. Purdue AY-217 uses this approach for live-seed emergence. If your survival figure already includes nongerminating seed, entering it here would count that loss twice.
Row width converts seeds per acre to seeds per foot. Seeds per unit and acres give the calculated number of bags for the field, before rounding the order. The unit size comes from the supplier.
For a target of 32,000 plants per acre, divide by 0.90 germination and 0.90 survival. The result is about 39,506 seeds per acre before display rounding. The example demonstrates the calculation; the target remains your decision.