Rapeseed and mustard belong to the family Cruciferae are important oil crops and currently ranked as the worlds third important oil crop in terms of production and area. However, the average seed yield of rapeseed and mustard is 0.71 t ha-1 in this country (BBS, 2004), which is far below the level as compared to that of the advanced countries. The major reasons for such poor yield of rapeseed and mustard in Bangladesh may be attributed to lack of improved varieties and poor management practices in the framers field. Establishment of optimum plant population by maintaining proper...