Abstract

                                Experiments were conducted twice to evaluate the influence of Bt cotton on Rotylenchulus reniformis under laboratory (28 o + 2 o C) and glasshouse conditions. Three Bt hybrids viz., Bunny Bt, RasiBt and Jagannath fusion Bt were compared with their respective non Bt (Refugia) for their impact on egg hatching, juveniles attraction, root penetration and development of R. reniformis. Jagannath fusion Bt and Rasi Bt were effective in inhibiting/delaying the egg hatching as compared to their non Bt lines whileBunny Bt had no significant effect in inhibiting the egg hatching over its non Bt. But Bt hybrids had no significant influence in causing mortality of juveniles, attraction of infective pre adult (J4 ) and penetration of R. reniformis. In all Bt hybrids, on 7 th day after inoculation reduction in number of females with egg mass was observed over its non Bt. The penetrated juveniles of R. reniformis were not able to become adults in Bt cotton.

Key words : Bt hybrids, Bunny Bt, Rasi Bt, Jagannath fusion Bt, Non Bt and Rotylenchulus reniformis