The performance of different Bt cotton hybrids were compared in mother and baby trial design to assess the potentiality under researcher managed (mother) Vs farmers growing practices (baby trial) in black soil under rainfed situation. The field experiment was conducted at Govankoppa village of Bailhongal taluk for two years (2008-09 and 2009-10). The results indicated that Bunny BG-II Bt recorded significantly higher seed cotton yield (2385 kg/ha) than JK-99 Bt (1920 kg/ha), Brahma Bt (1770 kg/ha) and DHH-11 Bt (1615 kg/ha). RCH - 708 Bt (37.05 mm) recorded significantly higher 2.5% span length (mm) compared to all other cotton genotypes except MRC - 6918 Bt (35.90mm). Bundle strength did not differ significantly with the cotton genotypes.  In baby trial, the seed cotton yield of RCH-708 Bt, RCH-2 Bt, JK-99 Bt and Brahma Bt could not vary significantly between mother and baby trial. Hence, in the present investigation it can be concluded that RCH-708 Bt, RCH-2 Bt, JK-99 Bt and Brahma Bt genotypes have recorded the maximum potential in both researcher managed (mother) and farmers practice (baby trial).