Management of sweet potato weevil through biopesticides

Sweet potato weevil is the most disastrous pest affecting sweet potato plantation. Entomopathogenic fungi are by far one of the most effective biological control agents of sweet potato weevil due to their host-specificity. A field experiment was conducted at Central Experimental Station, Wakawali, Dapoli, Maharashtra during Kharif seasons of 2008, 2009 and 2010 to manage the weevil infesting sweet potato. The treatments included Beauveria bassiana, Bio-Power 1.5 per cent WP @ 6.75 kg/ha, Metarhizium anisopliae Stanes, Bio-Magic 1.5 WP @ 11.25 kg/ha, mustard oil cake @ 10 tonnes/ha, neem cake @ 10 tonnes/ha, yam bean seed 5 per cent aqueous extract, cassava tuber rind 5 per cent aqueous extract, garlic 5 per cent aqueous extract, control (only water) and check (dimethoate 0.05% spray). The application of B bassiana @ 6.75 kg/ha and application of neem cake @ 10 tonnes/ha after one month of sweet potato planting proved most effective in reducing the damage to the sweet potato tubers and number of weevils.