Many tillage farmers have seed drills out this week. Many more are ordering seed, whichever job you are doing be sure to get your calculations right.
No matter what the crop, seed rate calculation in accordance with your predicted establishment is essential to ensure a plant stand with high yield potential.
Seed rate will change from year-to-year, between varieties and with different batches of seed, as the thousand grain weight (TGW) will differ.
- The target plant population (plants/m²);
- The TGW of the seed;
- The estimated plant establishment percentage.
Establishment rate should be high in current conditions, as ground conditions are favourable and soil temperatures are on the increase.
Spring barley crops planted in the month of March would be expected to have an establishment rate of approximately 85%.
Target plants/m² should increase into April. The establishment percentage will also increase towards the end of April, when temperatures are much higher.
- Up to mid March – 280 plants/m² (85% establishment);
- Mid to late March – 300 plants/m² (85% establishment);
- Early to mid April – 300 plants/m² (85% establishment);
- Late April – 325 plants/m² (90% establishment).
- Up to mid March – 325 plants/m² (85% establishment);
- Mid to late March – 350 plants/m² (85% establishment);
- Early to mid April – 350 plants/m² (85% establishment);
- Late April – 350 plants/m² (90% establishment).
- February – 300 plants/m² (80% establishment);
- Early to mid March – 325 plants/m² (85% establishment);
- Mid March to early April – 350 plants/m² (85% establishment).
- February – 30 plants/m² (75% establishment);
- March – 30 plants/m² (85% establishment);
- April – 35 plants/m² (95% establishment).