A diallel cross experiment involving eight parents was conducted to understand the genetic mechanism controlling harvest index in mungbean. Analysis of variance depicted highly significant differences for female, male parents and their interaction in F1 and F2 generations. The data for both the generations was found partially adequate when subjected to adequacy tests. Estimation of genetic components of variation revealed significance of both additive and non-additive components in both generations. In F1 generation degree of dominance was less than 1, indicating preponderance of additive gene effects while in F2 it was more than 1 showing over dominance type of gene action. Graphical differences revealed presence of additive gene action in both the generations
