Phenotypic correlation of seed yield and its component traits were studied in four selected single cross F2 corresponding F2M2, two three way and one double cross populations of blackgram. All the eleven populations exhibited significant positive correlation of plant height, number of clusters and pods per plant with seed yield per plant except two F2M2 populations for plant height. In the irradiated pOpulations, the magnitude of the association of plant height with seed yield was of lower order compared to other F2 populations. Irradiated population of single cross, TAU-1 x 169 exhibited significant correlation of pod length with seed yield per plant compared to its F2 population. The nature of correlation between pod length and number of pods per pod was changed from negative to positive consequent to irradiation of the cross, TAU-1 x 169. Most of the traits under study including pod length contributed towards seed yield per plant in single cross F2 and F2M2 and double cross populations.