4. In the case of barley, durum wheat, oats, spelt wheat and wheat, other than a hybrid in each case, the minimum varietal purity shall conform to the following standards—E+W
| Category | Minimum standard | Higher Voluntary Standard |
|---|---|---|
(a)Basic seed | 99.9 | 99.95 |
(b)C1 seed | 99.7 | 99.9 |
(c)C2 seed | 99.0 | 99.7 |