| Scale | Index rating system |
|---|---|
| 0z | No growth of fungi on the specimen, inhibition zone on the medium |
| 0 | No growth of fungi on the specimen |
| 1 | Less than 10% of the specimen area covered by fungi |
| 2 | Less than 30% of the specimen area covered by fungi |
| 3 | Less than 60% of the specimen area covered by fungi |
| 4 | Specimen totally overgrown by fungi |