A study on generation mean analysis was conducted to determine suitable genotypes of black gram (Vigna mungo L.) for rice fallowconditions, considering various agronomic traits controlled by quantitative inheritance. The Hayman’s six-parameter model, utilizinga Random Block layout with two replications over six generations viz., P1, P2, F1, F2, BC1, and BC2 involving six parents viz., MDU 1, VBN(BG) 6, Mash-114 and ADT 3, PU 31 and CO 6 was followed. The filial generations derived from four crosses, along with their parentsinvolved in the hybridization, were evaluated at TRRI, Aduthurai, during the summer of 2019 under rice fallow conditions. The focus ofthe evaluation was on yield and its nine component traits, including plant height, branches per plant, 50% flowering, pods per cluster,pod number, 100 seed weight, and single plant yield. The study revealed a predominant influence of the duplicate dominant gene onthese yield attributes, indicating the complexity of the genetic basis. This complexity suggests that conventional selection methods may be hindered, making heterosis breeding or bulk method/recurrent selection more favorable for obtaining the desired gene combinations in genotypes suitable for rice fallow conditions.