Comparison of Inbred Lines Within Two Groups

Sometimes we have two groups of inbred lines and there are only interest in gca comparisons within two groups of lines of sizes$\P_1$ and $\P_@$, not between two groups. For example, suppose there two Lab, each of the 2 Labs have obtained the best line. 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.