Experiences with incomplete block designs in Denmark

Incomplete block designs were first used in the statutory variety trials in Denmark in 1979. During the last years the use of incomplete block designs in variety trials has increased and is now used both for performance trials and DUS trials in most of the trials with many entries. The need for incomplete block designs has increased as the number of varieties in many crops has increased. Incomplete block designs are also used in a few other types of designs such as trials with different pesticides. Most of the incomplete block designs have been Alpha-designs. Examples of designs and the efficiency of such designs were presented together with a discussion of the most important benefits and drawbacks of using such designs