A-optimal diallel crosses for test versus control comparisons

A-optimality of block designs for control versus test comparisons in diallel crosses is investigated. A sufficient condition for designs to be A-optimal is derived. Type S0 designs are defined and A-optimal type S0 designs are characterized. A lower bound to the A-efficiency of type S0 designs is also given. Using the lower bound to A-efficiency, type S0 designs are shown to yield efficient designs for test versus control comparisons