Seeding rate example tables
Refer to Table 4 to see the variation in seeding rate as the seeding conditions change; for hybrids (Table 4a) and for open pollinated canola (Table 4b).
| Hybrid seed | Medium | Large | Very large |
|---|---|---|---|
| Seed size (mg) | 4 | 5 | 6.7 |
| Seeds/kg | 250 000 | 200 000 | 150 000 |
| 80% field establishment (excellent condition) | 1.6 | 2.0 | 2.6 |
| 65% field establishment (reasonable conditions) | 1.9 | 2.4 | 3.2 |
| 30% field establishment (dry seeding, tough start) | 4.2 | 5.3 | 7.0 |
| Open pollinated seed | Small | Medium | Large |
|---|---|---|---|
| Seed size (mg) | 2.9 | 3.3 | 4.0 |
| Seeds/kg | 350 000 | 300 000 | 250 000 |
| 65% field establishment (excellent conditions) | 1.9 | 2.2 | 2.6 |
| 50% field establishment (reasonable conditions) | 2.4 | 2.8 | 3.4 |
| 20% field establishment (dry seeding, tough start) | 6.0 | 7.0 | 8.4 |
Make a better decision next year
Assess the success rate this year, to make a better decision next year. Was the density better or worse than the target?
It is good to know the actual plant density. If the target density was better than expected, then the field establishment was better than estimated. The seed rate may be reduced, under similar seeding conditions.
Conversely, if the target density was worse than expected, the field establishment must have been lower than estimated. Was there a particular reason for this? Or was it just what can be expected of the machinery type? Consider increasing the seeding rate for the following season. Monitor the establishment in different paddocks, each season.
To assess crop density, work out the average number of plants per 1m row and the row spacing;
Crop density (plants/m2) = (average number of plants per 1m row x 100) / row spacing (cm)
For example, the plant density is 24plants/m2, where there is an average of six plants per 1m row and 25cm row spacing.
Calculate field establishment by rearranging the seeding rate calculation;
Field establishment = [crop density (plants/m2) x 10 000] / [seeding rate (kg/ha) x seeds/kg x germination]