Seed Replacement Rate & Split Certified from Own-Saved Seed
Plans wheat
SRR is the share of your seed bought fresh as certified seed rather than saved from last year — enter your area, seed rate per hectare and target SRR percent to get the certified seed, own-saved seed and total seed in kilograms.
Split your seed need
Next: buy 33 kg of fresh certified seed this season and reuse 67 kg of your own; raising the SRR each year refreshes more of the crop's genetics.
Seed Replacement Rate is the share of total seed that is fresh certified seed; higher SRR lifts genetic purity and yield potential but raises seed cost.
Seed replacement rate — key facts
- Total seed
- area (ha) × seed rate kg/ha
- Certified seed
- total × SRR%
- Own-saved seed
- total − certified
- Self-pollinated SRR
- ≈ 25–33% (every 3–4 yrs)
- Hybrid SRR
- 100% — can't save seed
- Wheat seed rate
- ≈ 100 kg/ha typical
- 1 acre
- = 0.405 hectare
- Privacy
- Runs in your browser; nothing uploaded
How much fresh seed to buy, and how much to keep back
Saved seed is cheap, but its quality drifts: purity slips, vigour falls and seed-borne disease builds over generations. Certified seed is tested for germination and purity, so replacing a share of your seed each year keeps the stand uniform and the yield up. The seed replacement rate is the dial that balances seed cost against that drift — a low SRR for self-pollinated crops you can save, and 100% for hybrids whose seed cannot be saved true to type.
This tool works out the certified seed, the own-saved seed and the total seed in kilograms from your field area, the seed rate per hectare and your target SRR, across acre, hectare, guntha, bigha or m². Use it to budget the certified seed to buy and the seed to keep back from harvest, and to plan a multi-year replacement cycle. Pair it with the Field Establishment, Plant Population Yield Response and GDD to Maturity tools to plan the crop end to end.
Budget certified seed
Know the fresh seed to buy this season.
Plan a replacement cycle
Set an SRR that refreshes seed every few years.
Keep quality up
Replace enough to hold purity and vigour.
Any crop & unit
Wheat, paddy or hybrids — per acre or hectare.
Frequently Asked Questions
How is the seed replacement rate split calculated?+
The tool finds the total seed for your field as area in hectares × seed rate per hectare. It then splits it by your target SRR: certified seed = total × SRR%, and own-saved seed = total − certified. So if you plan a 40% SRR, 40% of your seed is bought fresh as certified seed and the rest is saved from your own crop.
What is the seed replacement rate (SRR)?+
The seed replacement rate is the percentage of the seed you sow that is fresh certified seed rather than seed saved from your previous harvest. A 100% SRR means all new certified seed every season; a 25% SRR means a quarter is replaced each year and the rest is farm-saved. It is a standard agricultural planning figure, tracked nationally for major crops.
Why replace seed instead of saving it all?+
Saved seed slowly loses quality — varietal purity drifts, vigour falls and seed-borne disease builds up over generations. Certified seed is tested for germination and purity, so replacing a share each year keeps your stand uniform and high-yielding. The SRR is the dial that balances seed cost against that quality drift.
What is a good seed replacement rate?+
For self-pollinated crops like wheat and paddy, replacing seed roughly every three to four years — an SRR of around 25–33% — is a common recommendation, so each lot is no more than a few generations from certified. Cross-pollinated and hybrid crops need higher replacement, often 100% for hybrids whose seed cannot be saved true to type. Set the SRR your crop needs.
Why can't I save hybrid seed?+
Hybrid seed is the first generation from two parent lines and does not breed true — saving and sowing it gives a mix of weaker, variable plants and a big yield drop. That is why hybrid crops are planted at 100% SRR, buying fresh seed every season. For open-pollinated and self-pollinated varieties you can save seed and use a lower SRR.
What seed rate should I enter?+
Enter the recommended seed rate for your crop in kilograms per hectare — for example roughly 100 kg/ha for wheat or 60–80 kg/ha for transplanted paddy nursery, adjusted for your variety and method. The tool multiplies it by your area to get the total seed before splitting it by the SRR. Use a rate that matches your sowing method.
Does this work in acres and other units?+
Yes — enter your area in acres, hectares, guntha, bigha or m² and the tool converts to hectares internally before applying the seed rate. The certified, own-saved and total seed all come back in kilograms. So you can plan in whatever land unit you use locally.
Are the figures exact?+
The split is exact arithmetic from your inputs. The total seed depends on the seed rate you enter, so use a realistic rate for your crop and method, and remember to allow extra for germination and field losses where needed. Use it to budget the certified seed to buy and the own-saved seed to keep back.