Scale | % leaf area infected | Description |
0 - 1 | 0 | no infection |
1 - 2 | 3 | >1% but <10% |
2 - 3 | 10 | 11 - 20 small lesions |
3 - 4 | 25 | 10% leaf area infected |
4 - 5 | 50 | 25% leaf area infected |
5 - 6 | 75 | 50% leaf area infected |
6 - 7 | 90 | 75% leaf area infected |
7 - 8 | 97 | Only few green areas left (much less than 10%) |
8 - 9 | 100 | foliage completely destroyed/dead |