Twenty two Bt cotton hybrids were evaluated for seed cotton yield and fibre quality parameters over three environments viz., Agricultural Research Station, Siruguppa (E-1), Main Agricultural Research Station, Raichur (E-2) and Agricultural Research Station, Bheemarayanagudi (E-3), during Kharif 2010-11. The seed cotton yield ranged from 1478 to 2203 kg/ha among the Bt cotton hybrids. Pooled data of seed cotton yield revealed that two hybrids viz., MRC 7347 BG II (2203 kg/ha) and ACH 177-2 BG II (2054 kg/ha) recorded numerically superior seed cotton yield over the check, MRC-7351 BG-II (2053 kg/ha). The data on 2.5 per cent span length ranged from 29.2 mm to 33.6 mm, while the fibre strength of the hybrids ranged from 21.7 g/tex to 23.9 g/tex. Fibre fineness or micronaire value ranged from 3.9 to 4.6 g/inch. None of the hybrids were found to be stable across all the test environments indicating the need to undertake extensive testing of Bt cotton hybrids for recommending region specific hybrids possessing high yielding potential coupled with desirable fibre quality parameters.
