The best variety or an almost best one? : a comparison of subset selection procedures

Given are k varieties. The best variety is defined as the variety with the largest average yield per plot of common unit size. An almost best or an e:-best variety is a variety with an average yield on a distance not larger than \epsilon (\geq 0) from the best variety. Subset selection is considered for selection of the best variety, but also for selection of an \epsilon-best variety. A comparison between these two selection goals is made by investigating the relative efficiency of subset selection of an \epsilon-best variety. An application is the field of variety testing is presented.