Fisher’s LSD versus Tukey’s LSD
With Tukey’s procedure it is more difficult to find a difference than with Fisher’s protected LSD.
For example treatments 2, 5, and 4 are not statistically different when using Tukey’s procedure, but 2 and 4 are when using Fisher’s protected LSD.
Fisher’s LSD method does not offer full control of the experiment wise type I error rate, which Tukey’s does.