4. In the case of barley, durum wheat, oats, spelt wheat and wheat, the crop shall conform to the following standards as regards the minimum species purity—
| Crops to produce | Minimum standard (percentage by number) | Higher Voluntary Standard (percentage by number) |
|---|---|---|
(a)Basic seed | No standard | 99.99 |
(b)C1 seed | No standard | 99.99 |
(c)C2 seed | No standard | 99.99 |