Seeding rate & plant population
Seeds per hectare and kg of seed needed for your target stand, row width and germination.
Dryland about 15 000–25 000 under 500 mm rain, 25 000–40 000 at 500–700 mm, 40 000–55 000 above 700 mm on deep soils; irrigated 60 000–90 000 plants/ha
Printed on the seed bag or certificate. Certified seed is usually 85–95%.
Share of germinating seed that becomes an established plant: about 90% in a good seedbed, 70–80% with crusting, dry planting or pests.
Usually 280–400 g; check the bag
Dryland 0.9–2.1 m; high-potential 0.76–0.9 m
Hybrid maize is often sold in bags of 60 000 or 80 000 seeds.
How this is calculated
Not every seed becomes a plant, so you plant more seeds than the stand you want. Seeds per hectare = target plants ÷ (germination × field emergence). For 25 000 maize plants with 90% germination and 90% emergence: 25 000 ÷ (0.90 × 0.90) = 30 864 seeds/ha.
Seed mass: seeds per kg = 1 000 000 ÷ thousand-seed weight in grams, so 350 g gives 2 857 seeds/kg and 30 864 seeds need 10.8 kg/ha.
Spacing: a hectare has 10 000 ÷ row width metres of row (6 667 m at 1.5 m rows). 30 864 seeds over 6 667 m is 4.6 seeds per metre, one seed every 21.6 cm. Set the planter to this spacing and check it in the field.
The crop hints are typical ranges only. The right population depends on your rainfall, soil depth and cultivar, so follow your seed supplier's recommendation for your area.
Read the guide: Plant population: how many seeds to plant for your rainfall
Results are estimates for planning. Check product labels and local recommendations before you apply anything.