Dunnet tests weather means are different from the mean of the control (The common control in our system is the variety M82). This multiple comparison test takes in consideration the number of independent comparisons that are being made, under the assumption that there are a number of random mistakes and this number is proportional to the number of comparisons being made. Under this assumption, the confidence level is adjusted to the number of comparisons.

Dunnet CW (1955) A multiple comparison procedure for comparing several treatments with a control. J Am Stat Assoc 50:1096-1121