Commercial seeds · Evidence before procurement
How to set sowing density from a target plant stand
Work backwards: divide the target plants per m² by the documented germination and expected field emergence to get seeds per m². For seed sold by weight, multiply by thousand-seed weight to get kg per hectare. Every input must come from the seed label, a test report or local experience.
SeedMatchGroup editorial team · Published and source pages checked · Educational planning, not laboratory certification or a crop diagnosis.
Symptoms to record
- The sowing rate was copied from a previous season without new test results.
- Seed is ordered by weight but the target is a plant count.
- Stands are consistently above or below plan.
Diagnostic evidence path
1. Is the target stand documented?
Use the target from local advice or variety guidance for your system and sowing date.
2. Which germination figure applies?
Use the current label or test report for the lot you will sow.
3. What field emergence is realistic?
Use your own stand counts from comparable seasons; treat any assumption as a scenario.
4. Is seed priced by count or weight?
Convert with thousand-seed weight only for weight-based lots.
Worked example — stated assumptions
Hypothetical cereal planning: 300 target plants/m² ÷ 0.80 field emergence = 375 grains/m². With thousand-grain weight 48 g and 95% germination: 375 × 48 ÷ 95 = 189.5 kg/ha. The formula follows LfL Bayern’s planning calculator; the inputs are illustrative.
Calculate seed rate →Related guides and tools
When expert help is needed
Confirm targets with a local agronomist; sowing date, seedbed and variety change the right stand.
Buyer questions
Is more seed always safer?
No. Excess density can increase competition and cost; base the rate on evidence.
Should field emergence be 95%?
Not universally. Use your own records; any figure here is illustrative.
Does this apply to transplants?
For transplanted crops plan by plant count and nursery losses instead.
From observation to a private seed request
Free planning arithmetic. Starting values are hypothetical, not a recommended stand or lot acceptance threshold. Nothing is saved or sent until you submit a brief.
Review official crop data, seed-lot evidence and import references before preparing your request →
Target plants ÷ (germination fraction × post-germination establishment fraction × applicable purity fraction). Confirm the unit basis; do not double-count physical purity or field losses. Zero germination cannot be compensated by ordering more.
Free project workspace (sign-in required) · Existing greenhouse ROI scenarios
Sources and methodology
ISTA informs the distinction between standardized testing and observations; OECD explains varietal certification; Minnesota Extension illustrates why seeding rates depend on production context. Examples here are hypothetical arithmetic, not borrowed crop recommendations. Check the current scheme and local requirements with qualified professionals.