Diallel cross designs for test versus control comparisons

Abstract

Block designs for diallel crosses for comparing a group of test lines with a control line are suitable when the experimenters are interested to estimate test vs. control comparisons with respect to their general combining ability effects with a smaller variance. In this paper, some families of small block designs for diallel cross experiments for test vs. control comparisons have been obtained. Out of these, some designs are suitable when the experimenter cannot have blocks of equal size while the others yield designs with equal block size. As the number of lines increases, the variance of estimated contrasts pertaining to test vs. test lines as well as test vs. control lines decreases. Moreover, test vs. control comparisons are made with less variance as compared to test vs. test comparisons, in all the cases.