Evaluation of Some Plant Products of Tripura, North-East India for Piscicidal Property

The study was carried out to examine the acute toxicity of leaves of Moringa oleifera (Drumstick), barks of M. oleifera, leaves of Camellia sinensis (Tea), barks of Magnolia champaka (Champak), fruits of Melia azedarach (Chinaberry), leaves of Glycyrrhiza glabra (Mulethi), leaves of Millettia pachycarpa (Bish lata), seeds of Jatropha curcas (Bherenda) and Hevea brasiliensis (Rubber), leaves of Tephrosia purpurea (Bannilgach), leaves of Dioscorea alata (Banalu) and fruits of Trichosanthes tricuspidata (Makal) with an aim of using them as low-cost piscicides for eradication of weed fishes during pond preparation for seed rearing. The products were locally collected, processed and their aqueous extracts were prepared (1:5) and then their potency was evaluated against Puntius sophore (Sophore barb), a weed fish. The test method followed was static bio-assay (24 hr and 48 hr). Test concentrations of the extracts were assessed through range finding study. Median lethal concentrations (LC50) were estimated by probit analysis. All products were observed effective as piscicide. Tea leaves’ extract was observed most effective followed by extract of Tephrosia leaves, Jatropha seed, Trichosanthes fruits, Rubber seed, Moringa barks, Moringa leaves, Dioscorea leaves, Magnolia barks, Millettia leaves, Glycyrrhiza leaves and fruits of Melia. The 24h LC50 varied from 11.0 to 247 ml/L and 48h LC50 from 9.2 to 202 ml/L. From, this study, it could be concluded that aqueous extracts of leaves of tea, Tephrosia, Moringa, Dioscorea, Millettia and Glycyrrhiza, seeds of Jatropha and Rubber, barks of Moringa and Magnolia and fruits of Trichosanthes and Melia possess piscicidal property; hence, they are useful as low-cost bio-piscicides.