Block Designs for Comparisons within Two Groups of Inbred Lines in Diallel Crosses

Sometimes we have two groups of inbred lines and there are only interest in gca comparisons within group($p_{1}$) and group($p_{2}$) and not between two groups. For example, suppose there two Lab, each of the 2 Labs have obtained the best lines. For this purpose we now give a method of constructing block designs for diallel cross experiments and we will explain how to calculate efficiency. Then we show the efficiencies in the table.