Reaction of Bt and Popular Varieties of Cotton to Rotylenchulus reniformis

The Bt cotton, MECH 184 and non-Bt cotton varieties were studied for their effect on reniform nematode. The study showed that there was significant reduction in reniform nematode population, Rotylenchulus reniformis, and subsequent increase in biomass of cotton. Development of nematode and egg production is also delayed in Bt cotton. Further, root leacheats from Bt and non Bt cotton plants were taken to study the effect of toxin on nematode through contact nematicidal assay, influence on egg hatching, penetration of juveniles in cotton root under glasshouse conditions. The results showed no mortality of juveniles in contact nematicidal assay. However 3–4 days delay in hatching and subsequent development to J3 stage in Bt cotton. Penetration study showed normal penetration of J4 in roots of both Bt and non Bt cotton.