This is an old revision of this page, as edited by Maccheek (talk | contribs) at 11:26, 12 February 2007 (←Created page with 'The Horsfall-Barratt scale <ref name=Horsfall&Barratt>{{Citation | last1 = Horsfall | First1 = J. G. | last2 = Barratt | First2 = R. W. | title = An Improved Gradi...'). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
The Horsfall-Barratt scale [1] is a system of assessing plant diseases where
| Index | Percent Affected |
|---|---|
| 1 | 0 |
| 2 | 0 to 3 |
| 3 | 3 to 6 |
| 4 | 6 to 12 |
| 5 | 12 to 25 |
| 6 | 25 to 50 |
| 7 | 50 to 75 |
| 8 | 75 to 87 |
| 9 | 87 to 94 |
| 10 | 94 to 97 |
| 11 | 97 to 100 |
| 12 | 100 |
The scale is often used in modified form with index values from 0-11 or with different numbers of index points.