Abstract: Striga hermonthica has been identified as an economic parasitic weed affecting high grain yield production of sorghum in Africa particularly Nigeria. Seven sorghum varieties were evaluated for three years (1998-2000) in soil treated with Striga seeds using two sources of nitrogen fertilizer and at five levels of nitrogen to study their association in the control of Striga. The experiment was split-split plot with three replication having sorghum varieties as main plot, source of fertilizer as sub-plot and levels of N as sub-sub plot treatments. There were no significant differences among sources of fertilizer and their interactions. Levels of N and varieties were significant for all the traits (p<0.001). There was positive and significant association between levels of N applied and plant vigour, dry matter yield (shoot and root) p<0.01 and Striga count (p<0.05). The significant linear relationship obtained, recognized plant vigour, dry matter yield and Striga count as beneficial Striga resistance indicator. Between 50 to 100 ppm (when converted 110 to 170 kg of N ha-1) is significant in the control of Striga. SK-5912, KSV-4, KSV-8 and NR71150 are potential sources of Striga resistance.