The graphic and the combining ability analysis techniques of analysing diallel crosses were compared by using data obained from F1’s, F2’s and F3’s of all possible combinations of five varieties of wheat. The combining ability analysis was found to be better than the graphic analysis in predicting the prepotency of cultures. It was especially so in later generations when the expression of dominance effects is reduced. Graphic analysis gave consistant results in the presence of a high degree of dominance of alleles but failed to identify small but considerable proportions of non-allelic effects. When the degree of dominance was low, even small proportions of non-allelic effects were observed to confound the results. The graphic method was however, helpful in classifying the parents on the basis of allelic content.
