Efficacy of Ricinus communis L., Cassia occidentalis L. and Bacillus thuringiensis against Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

Helicoverpaarmigera is one of the most destructive pests field crops worldwide. The Study was designed to investigate through laboratory screening insecticidal activity Ricinus communis, Cassia occidentalis and Bacillus thuringiensis var. Kurstaki (Btk) their combinations against 2nd larval instar H. armigera. Five concentrations (4%, 6%, 8%, 10% 12%) each plant extract (0.62, 1.25, 2.5, 5, 10 mg/ml) Bt were used in this experiment. Mortality (%) recorded after 24,48,72 96 hrs post treatment. results showed that R. C. Btkhave larvae highest concentration (12%) caused 80% 70% mortality for communis occidental respectively. statistical analysis revealed there a significant differences between all treatments control. Additionally, (plant/plant or plant/Bt) increased %. also clearly demonstrate are significantly more toxic than where LC50 values 6.4 % 8.1% occidental. On other hand value 0.41 mg/ml. binary mixture have potentiation effect 48 hrs. Regarding extracts induced whereas an additive effects.