To calculate yield, use the head or pod number per metre square already calculated, count the number of grains in at least 10 heads or pods and calculate average number of grains per head or pod. Do not count all large heads as this will lead to an over estimate. Estimate grain weight using the table below.
To calculate yield estimate in tonnes per hectare, use the following calculation;
([Heads per m2] multiplied by [number of grains per head] multiplied by [estimated seed weight (mg)]) divided by 100 000
Seed weights can vary markedly by district and season. The following table should be used as a guide only.
| Crop | Approximate seed weight (mg) |
|---|---|
| Wheat | 30-45 |
| Barley | 35-45 |
| Field peas | 200-250 |
| Lupins | 150-200 |
| Canola - hybrid | 4-6 |
| Canola - open pollinated | 3-4 |