Field evaluation of eight commercial neem based formulations viz Neem Gold, Nimbo Bas, Multineem, Nimbex, NeemAzal, Nimbecidine, Neemarin and Achook having 0.03, 0.15, 0.03, 0.03, 1.00, 0.03, 0.15 and 0.03 per cent azadirachtin, respectively, neem seed kernel extract (NSKE) (5%) and Ha NPV was done against the bollworms of cotton. Four NPV products viz Helicide, Helinash, Biovirus and PDBC virus were also evaluated for their efficacy against the bollworms of cotton. NSKE, NeemAzal and Nimbecidine were found to be highly effective in reducing the damage to the cotton bolls. Among the four Helicoverpa NPV products, PDBC virus and Helinash were the most effective in suppressing the damage by the bollworms. All the biopesticides were superior to the standard check, endosulfan, in preventing the damage to bolls after four sprays recording significantly higher yields over untreated control. The cotton plots treated with NSKE (5%) recorded the highest yield of 11.60 q/ha followed by the plots treated with NeemAzal (11.05 q/ha), PDBC virus (10.49 q/ha), Nimbecidine (10.43q/ha), Helinash (10.12 q/ha) and Nimbo Bas (9.88 q/ha).
Neem, bollworms, cotton, Ha NPV
