Farm tools
Know your farmBefore you commit
19 free farm tools on South African figures: Grain SA, SAFEX and the Land Bank. Pick one, type your own numbers.
Seed rate
How much seed a hectare, and what does it cost?
1. Your crop
Seed line in the crop budget: R 1 806.71/ha (Grain SA 2026-09-04, one total; Grain SA publishes no seed count or price behind it).
2. The plants you want
3. Your seed bag and price
From the bag and your quote: no South African source publishes seed prices or a cultivar's seed size.
The answer
31 000 plants a hectare at 70% germination and 100% field emergence need 44 286 seeds a hectare. Enter the seed count or mass and the price from your bag to cost it.
| Plants wanted (guide) | 31 000/ha |
| Germination (legal minimum) | 70% |
| Field emergence (no losses counted) | 100% |
| Seeds to plant | 44 286/ha |
| Crop budget seed line (Grain SA) | R 1 807/ha |
If field emergence is 10 points lower (90%): 49 206 seeds a hectare (hypothetical, not a forecast).
No field losses are counted: no South African guide publishes a field emergence for maize. Enter what you expect. Germination is the legal minimum for seed sold in South Africa (70%); the figure on your bag is likely higher and needs less seed.
Seeds = plants / (germination x emergence). Not which population to plant: that is your cultivar, soil, rainfall and agronomist. The legal germination minimums: Plant Improvement Act Regulations, 2025 (Government Notice R6852 of 2025), Table 4: Requirements for seed and seed samples [Reg. 27], column 6.
Choose what goes along to the other crop tools
What you untick starts from Grain SA's figures in the other tool. Nothing personal goes along: farm figures only.
How this works and the sources
How much seed the plant population you want takes: the seeds a hectare after germination and field emergence, the kilograms or bags from the seed count or mass on your bag, the seeds a metre of row at your row width, and the seed cost a hectare and on your hectares against the seed line of your crop budget. The population starts from what a South African guide publishes for the crop; type your cultivar's recommendation over it.
What this does not tell you
- This does not tell you which population to plant. That comes from your cultivar, soil, rainfall and agronomist; the guides' figures are a starting point, and the maize guide is from 2003.
- Germination starts at the legal minimum for seed sold in South Africa; your bag's figure is usually higher and needs less seed. Field emergence is a published figure only for soybeans and wheat; for the other crops no field losses are counted until you enter your own.
- No South African source publishes seed prices or a cultivar's seed size: the seed count or mass and the price come from your bag and your quote. Grain SA's seed line is one total a hectare with no count or price behind it.
- One population over the whole land: no variable rate, and no adjustment for an early or late planting date.
- Nothing you enter is uploaded or kept by us; the share link carries farm figures only, never a cultivar or supplier name.
Sources
- Department of Agriculture with ARC-Grain Crops Institute, Maize production (J. du Plessis, 2003), Table 5: Guidelines for a realistic plant population (2003-01-01)
- Grain SA, Pula Imvula December 2015: Recommendations for soybean plant establishment (N. Barnard, Pannar) (2015-12-01)
- Grain SA, Pula Imvula April 2017: Science supports sunflower production (2017-04-01)
- ARC-Grain Crops Institute, Sorghum production (fact sheet) (2013-11-06)
- ARC-Small Grain, University of the Free State, ABInBev and SABBI: Guidelines for the production of small grains in the summer rainfall region (2019) (2019-03-18)
- Plant Improvement Act Regulations, 2025 (Government Notice R6852 of 2025), Table 4: Requirements for seed and seed samples [Reg. 27], column 6 (2025-11-21)
- Grain SA summer grain production budgets 2026/27 (2026-09-04)
Estimate, not advice. Confirm every figure with your bank, attorney and tax practitioner before a decision.