| Location | Treatmenta | 2008 | 2009 | 2010 | 2011 | |
| Pre-plant | Post-harvest | Post-harvest | Post-harvest | Post-harvest | ||
|
|
| mg∙kg−1 | ||||
| Jackson | 1 | 26.9 | 21.4 | 17.1bb | 34.3 | 25.9 |
|
| 2 | 23.0 | 20.9 | 20.9b | 28.6 | 26.1 |
|
| 3 | 28.6 | 23.8 | 18.1b | 30.4 | 20.5 |
|
| 4 | 26.5 | 24.0 | 17.4b | 33.8 | 33.9 |
|
| 5 | 28.8 | 28.1 | 29.4a | 31.4 | 30.6 |
|
| 6 | 26.0 | 20.1 | 18.4b | 22.9 | 26.6 |
|
| Sigc | nsd | ns | * | ns | ns |
| Milan | 1 | 17.1 | 24.6 | 14.5 | 18.9 | 16.6d |
|
| 2 | 18.1 | 25.1 | 15.8 | 23.0 | 21.9bcd |
|
| 3 | 16.5 | 27.3 | 15.3 | 20.4 | 28.0ab |
|
| 4 | 14.6 | 28.6 | 17.6 | 13.8 | 26.3bc |
|
| 5 | 20.4 | 30.0 | 19.8 | 18.6 | 35.1a |
|
| 6 | 16.9 | 21.4 | 11.6 | 18.0 | 19.1cd |
|
| Sig | ns | ns | ns | ns | ** |